linux/fs/ext4/ialloc.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ext4/ialloc.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* BSD ufs-inspired inode and directory allocation by
* Stephen Tweedie (sct@redhat.com), 1993
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/random.h>
#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <linux/cred.h>
#include <asm/byteorder.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
#include <trace/events/ext4.h>
/*
* ialloc.c contains the inodes allocation and deallocation routines
*/
/*
* The free inodes are managed by bitmaps. A file system contains several
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
* block for inodes, N blocks for the inode table and data blocks.
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block.
*/
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
/*
* To avoid calling the atomic setbit hundreds or thousands of times, we only
* need to use it within a single byte (to ensure we get endianness right).
* We can use memset for the rest of the bitmap as there are no other users.
*/
void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
{
int i;
if (start_bit >= end_bit)
return;
ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
ext4_set_bit(i, bitmap);
if (i < end_bit)
memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
}
void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
{
if (uptodate) {
set_buffer_uptodate(bh);
set_bitmap_uptodate(bh);
}
unlock_buffer(bh);
put_bh(bh);
}
static int ext4_validate_inode_bitmap(struct super_block *sb,
struct ext4_group_desc *desc,
ext4_group_t block_group,
struct buffer_head *bh)
{
ext4_fsblk_t blk;
struct ext4_group_info *grp;
if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
return 0;
if (buffer_verified(bh))
return 0;
grp = ext4_get_group_info(sb, block_group);
ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2023-04-29 04:06:28 +00:00
if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
return -EFSCORRUPTED;
ext4_lock_group(sb, block_group);
if (buffer_verified(bh))
goto verified;
blk = ext4_inode_bitmap(sb, desc);
if (!ext4_inode_bitmap_csum_verify(sb, desc, bh) ||
ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
ext4_unlock_group(sb, block_group);
ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
"inode_bitmap = %llu", block_group, blk);
ext4_mark_group_bitmap_corrupted(sb, block_group,
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
return -EFSBADCRC;
}
set_buffer_verified(bh);
verified:
ext4_unlock_group(sb, block_group);
return 0;
}
/*
* Read the inode allocation bitmap for a given block_group, reading
* into the specified slot in the superblock's bitmap cache.
*
* Return buffer_head of bitmap on success, or an ERR_PTR on error.
*/
static struct buffer_head *
ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
{
struct ext4_group_desc *desc;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct buffer_head *bh = NULL;
ext4_fsblk_t bitmap_blk;
int err;
desc = ext4_get_group_desc(sb, block_group, NULL);
if (!desc)
return ERR_PTR(-EFSCORRUPTED);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
bitmap_blk = ext4_inode_bitmap(sb, desc);
if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
(bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
ext4_error(sb, "Invalid inode bitmap blk %llu in "
"block_group %u", bitmap_blk, block_group);
ext4_mark_group_bitmap_corrupted(sb, block_group,
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
return ERR_PTR(-EFSCORRUPTED);
}
bh = sb_getblk(sb, bitmap_blk);
if (unlikely(!bh)) {
ext4_warning(sb, "Cannot read inode bitmap - "
"block_group = %u, inode_bitmap = %llu",
block_group, bitmap_blk);
return ERR_PTR(-ENOMEM);
}
if (bitmap_uptodate(bh))
goto verify;
lock_buffer(bh);
if (bitmap_uptodate(bh)) {
unlock_buffer(bh);
goto verify;
}
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
ext4_lock_group(sb, block_group);
if (ext4_has_group_desc_csum(sb) &&
(desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
if (block_group == 0) {
ext4_unlock_group(sb, block_group);
unlock_buffer(bh);
ext4_error(sb, "Inode bitmap for bg 0 marked "
"uninitialized");
err = -EFSCORRUPTED;
goto out;
}
memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
sb->s_blocksize * 8, bh->b_data);
set_bitmap_uptodate(bh);
set_buffer_uptodate(bh);
set_buffer_verified(bh);
ext4_unlock_group(sb, block_group);
unlock_buffer(bh);
return bh;
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
}
ext4_unlock_group(sb, block_group);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
if (buffer_uptodate(bh)) {
/*
* if not uninit if bh is uptodate,
* bitmap is also uptodate
*/
set_bitmap_uptodate(bh);
unlock_buffer(bh);
goto verify;
}
/*
* submit the buffer_head for reading
*/
trace_ext4_load_inode_bitmap(sb, block_group);
ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);
ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
if (!buffer_uptodate(bh)) {
put_bh(bh);
ext4_error_err(sb, EIO, "Cannot read inode bitmap - "
"block_group = %u, inode_bitmap = %llu",
block_group, bitmap_blk);
ext4_mark_group_bitmap_corrupted(sb, block_group,
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
return ERR_PTR(-EIO);
}
verify:
err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
if (err)
goto out;
return bh;
out:
put_bh(bh);
return ERR_PTR(err);
}
/*
* NOTE! When we get the inode, we're the only people
* that have access to it, and as such there are no
* race conditions we have to worry about. The inode
* is not on the hash-lists, and it cannot be reached
* through the filesystem because the directory entry
* has been deleted earlier.
*
* HOWEVER: we must make sure that we get no aliases,
* which means that we have to call "clear_inode()"
* _before_ we mark the inode not in use in the inode
* bitmaps. Otherwise a newly created file might use
* the same inode number (not actually the same pointer
* though), and then we'd have two inodes sharing the
* same inode number and space on the harddisk.
*/
void ext4_free_inode(handle_t *handle, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
int is_directory;
unsigned long ino;
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *bh2;
ext4_group_t block_group;
unsigned long bit;
struct ext4_group_desc *gdp;
struct ext4_super_block *es;
struct ext4_sb_info *sbi;
int fatal = 0, err, count, cleared;
struct ext4_group_info *grp;
if (!sb) {
printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
"nonexistent device\n", __func__, __LINE__);
return;
}
if (atomic_read(&inode->i_count) > 1) {
ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
__func__, __LINE__, inode->i_ino,
atomic_read(&inode->i_count));
return;
}
if (inode->i_nlink) {
ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
__func__, __LINE__, inode->i_ino, inode->i_nlink);
return;
}
sbi = EXT4_SB(sb);
ino = inode->i_ino;
ext4_debug("freeing inode %lu\n", ino);
trace_ext4_free_inode(inode);
dquot_initialize(inode);
dquot_free_inode(inode);
is_directory = S_ISDIR(inode->i_mode);
/* Do this BEFORE marking the inode not in use or returning an error */
ext4_clear_inode(inode);
es = sbi->s_es;
if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
ext4_error(sb, "reserved or nonexistent inode %lu", ino);
goto error_return;
}
block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
/* Don't bother if the inode bitmap is corrupt. */
if (IS_ERR(bitmap_bh)) {
fatal = PTR_ERR(bitmap_bh);
bitmap_bh = NULL;
goto error_return;
}
if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
grp = ext4_get_group_info(sb, block_group);
ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2023-04-29 04:06:28 +00:00
if (!grp || unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
fatal = -EFSCORRUPTED;
goto error_return;
}
}
BUFFER_TRACE(bitmap_bh, "get_write_access");
fatal = ext4_journal_get_write_access(handle, sb, bitmap_bh,
EXT4_JTR_NONE);
if (fatal)
goto error_return;
fatal = -ESRCH;
gdp = ext4_get_group_desc(sb, block_group, &bh2);
if (gdp) {
BUFFER_TRACE(bh2, "get_write_access");
fatal = ext4_journal_get_write_access(handle, sb, bh2,
EXT4_JTR_NONE);
}
ext4_lock_group(sb, block_group);
cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
if (fatal || !cleared) {
ext4_unlock_group(sb, block_group);
goto out;
}
count = ext4_free_inodes_count(sb, gdp) + 1;
ext4_free_inodes_set(sb, gdp, count);
if (is_directory) {
count = ext4_used_dirs_count(sb, gdp) - 1;
ext4_used_dirs_set(sb, gdp, count);
ext4: fix accessing uninit percpu counter variable with fast_commit When running generic/527 with fast_commit configuration, the following issue is seen on Power. With fast_commit, during ext4_fc_replay() (which can be called from ext4_fill_super()), if inode eviction happens then it can access an uninitialized percpu counter variable. This patch adds the check before accessing the counters in ext4_free_inode() path. [ 321.165371] run fstests generic/527 at 2021-04-29 08:38:43 [ 323.027786] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: block_validity. Quota mode: none. [ 323.618772] BUG: Unable to handle kernel data access on read at 0x1fbd80000 [ 323.619767] Faulting instruction address: 0xc000000000bae78c cpu 0x1: Vector: 300 (Data Access) at [c000000010706ef0] pc: c000000000bae78c: percpu_counter_add_batch+0x3c/0x100 lr: c0000000006d0bb0: ext4_free_inode+0x780/0xb90 pid = 5593, comm = mount ext4_free_inode+0x780/0xb90 ext4_evict_inode+0xa8c/0xc60 evict+0xfc/0x1e0 ext4_fc_replay+0xc50/0x20f0 do_one_pass+0xfe0/0x1350 jbd2_journal_recover+0x184/0x2e0 jbd2_journal_load+0x1c0/0x4a0 ext4_fill_super+0x2458/0x4200 mount_bdev+0x1dc/0x290 ext4_mount+0x28/0x40 legacy_get_tree+0x4c/0xa0 vfs_get_tree+0x4c/0x120 path_mount+0xcf8/0xd70 do_mount+0x80/0xd0 sys_mount+0x3fc/0x490 system_call_exception+0x384/0x3d0 system_call_common+0xec/0x278 Cc: stable@kernel.org Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/6cceb9a75c54bef8fa9696c1b08c8df5ff6169e2.1619692410.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-29 10:43:44 +00:00
if (percpu_counter_initialized(&sbi->s_dirs_counter))
percpu_counter_dec(&sbi->s_dirs_counter);
}
ext4_inode_bitmap_csum_set(sb, gdp, bitmap_bh);
ext4_group_desc_csum_set(sb, block_group, gdp);
ext4_unlock_group(sb, block_group);
ext4: fix accessing uninit percpu counter variable with fast_commit When running generic/527 with fast_commit configuration, the following issue is seen on Power. With fast_commit, during ext4_fc_replay() (which can be called from ext4_fill_super()), if inode eviction happens then it can access an uninitialized percpu counter variable. This patch adds the check before accessing the counters in ext4_free_inode() path. [ 321.165371] run fstests generic/527 at 2021-04-29 08:38:43 [ 323.027786] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: block_validity. Quota mode: none. [ 323.618772] BUG: Unable to handle kernel data access on read at 0x1fbd80000 [ 323.619767] Faulting instruction address: 0xc000000000bae78c cpu 0x1: Vector: 300 (Data Access) at [c000000010706ef0] pc: c000000000bae78c: percpu_counter_add_batch+0x3c/0x100 lr: c0000000006d0bb0: ext4_free_inode+0x780/0xb90 pid = 5593, comm = mount ext4_free_inode+0x780/0xb90 ext4_evict_inode+0xa8c/0xc60 evict+0xfc/0x1e0 ext4_fc_replay+0xc50/0x20f0 do_one_pass+0xfe0/0x1350 jbd2_journal_recover+0x184/0x2e0 jbd2_journal_load+0x1c0/0x4a0 ext4_fill_super+0x2458/0x4200 mount_bdev+0x1dc/0x290 ext4_mount+0x28/0x40 legacy_get_tree+0x4c/0xa0 vfs_get_tree+0x4c/0x120 path_mount+0xcf8/0xd70 do_mount+0x80/0xd0 sys_mount+0x3fc/0x490 system_call_exception+0x384/0x3d0 system_call_common+0xec/0x278 Cc: stable@kernel.org Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/6cceb9a75c54bef8fa9696c1b08c8df5ff6169e2.1619692410.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-29 10:43:44 +00:00
if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
percpu_counter_inc(&sbi->s_freeinodes_counter);
if (sbi->s_log_groups_per_flex) {
struct flex_groups *fg;
fg = sbi_array_rcu_deref(sbi, s_flex_groups,
ext4_flex_group(sbi, block_group));
atomic_inc(&fg->free_inodes);
if (is_directory)
atomic_dec(&fg->used_dirs);
}
BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
out:
if (cleared) {
BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
if (!fatal)
fatal = err;
} else {
ext4_error(sb, "bit already cleared for inode %lu", ino);
ext4_mark_group_bitmap_corrupted(sb, block_group,
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
}
error_return:
brelse(bitmap_bh);
ext4_std_error(sb, fatal);
}
struct orlov_stats {
__u64 free_clusters;
__u32 free_inodes;
__u32 used_dirs;
};
/*
* Helper function for Orlov's allocator; returns critical information
* for a particular block group or flex_bg. If flex_size is 1, then g
* is a block group number; otherwise it is flex_bg number.
*/
static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
int flex_size, struct orlov_stats *stats)
{
struct ext4_group_desc *desc;
if (flex_size > 1) {
struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
s_flex_groups, g);
stats->free_inodes = atomic_read(&fg->free_inodes);
stats->free_clusters = atomic64_read(&fg->free_clusters);
stats->used_dirs = atomic_read(&fg->used_dirs);
return;
}
desc = ext4_get_group_desc(sb, g, NULL);
if (desc) {
stats->free_inodes = ext4_free_inodes_count(sb, desc);
stats->free_clusters = ext4_free_group_clusters(sb, desc);
stats->used_dirs = ext4_used_dirs_count(sb, desc);
} else {
stats->free_inodes = 0;
stats->free_clusters = 0;
stats->used_dirs = 0;
}
}
/*
* Orlov's allocator for directories.
*
* We always try to spread first-level directories.
*
* If there are blockgroups with both free inodes and free clusters counts
* not worse than average we return one with smallest directory count.
* Otherwise we simply return a random group.
*
* For the rest rules look so:
*
* It's OK to put directory into a group unless
* it has too many directories already (max_dirs) or
* it has too few free inodes left (min_inodes) or
* it has too few free clusters left (min_clusters) or
* Parent's group is preferred, if it doesn't satisfy these
* conditions we search cyclically through the rest. If none
* of the groups look good we just look for a group with more
* free inodes than average (starting at parent's group).
*/
static int find_group_orlov(struct super_block *sb, struct inode *parent,
ext4_group_t *group, umode_t mode,
const struct qstr *qstr)
{
ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
struct ext4_sb_info *sbi = EXT4_SB(sb);
ext4_group_t real_ngroups = ext4_get_groups_count(sb);
int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
unsigned int freei, avefreei, grp_free;
ext4_fsblk_t freec, avefreec;
unsigned int ndirs;
int max_dirs, min_inodes;
ext4_grpblk_t min_clusters;
ext4_group_t i, grp, g, ngroups;
struct ext4_group_desc *desc;
struct orlov_stats stats;
int flex_size = ext4_flex_bg_size(sbi);
struct dx_hash_info hinfo;
ngroups = real_ngroups;
if (flex_size > 1) {
ngroups = (real_ngroups + flex_size - 1) >>
sbi->s_log_groups_per_flex;
parent_group >>= sbi->s_log_groups_per_flex;
}
freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
avefreei = freei / ngroups;
freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
avefreec = freec;
do_div(avefreec, ngroups);
ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
if (S_ISDIR(mode) &&
((parent == d_inode(sb->s_root)) ||
(ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
int best_ndir = inodes_per_group;
int ret = -1;
if (qstr) {
hinfo.hash_version = DX_HASH_HALF_MD4;
hinfo.seed = sbi->s_hash_seed;
ext4: Support case-insensitive file name lookups This patch implements the actual support for case-insensitive file name lookups in ext4, based on the feature bit and the encoding stored in the superblock. A filesystem that has the casefold feature set is able to configure directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups to succeed in that directory in a case-insensitive fashion, i.e: match a directory entry even if the name used by userspace is not a byte per byte match with the disk name, but is an equivalent case-insensitive version of the Unicode string. This operation is called a case-insensitive file name lookup. The feature is configured as an inode attribute applied to directories and inherited by its children. This attribute can only be enabled on empty directories for filesystems that support the encoding feature, thus preventing collision of file names that only differ by case. * dcache handling: For a +F directory, Ext4 only stores the first equivalent name dentry used in the dcache. This is done to prevent unintentional duplication of dentries in the dcache, while also allowing the VFS code to quickly find the right entry in the cache despite which equivalent string was used in a previous lookup, without having to resort to ->lookup(). d_hash() of casefolded directories is implemented as the hash of the casefolded string, such that we always have a well-known bucket for all the equivalencies of the same string. d_compare() uses the utf8_strncasecmp() infrastructure, which handles the comparison of equivalent, same case, names as well. For now, negative lookups are not inserted in the dcache, since they would need to be invalidated anyway, because we can't trust missing file dentries. This is bad for performance but requires some leveraging of the vfs layer to fix. We can live without that for now, and so does everyone else. * on-disk data: Despite using a specific version of the name as the internal representation within the dcache, the name stored and fetched from the disk is a byte-per-byte match with what the user requested, making this implementation 'name-preserving'. i.e. no actual information is lost when writing to storage. DX is supported by modifying the hashes used in +F directories to make them case/encoding-aware. The new disk hashes are calculated as the hash of the full casefolded string, instead of the string directly. This allows us to efficiently search for file names in the htree without requiring the user to provide an exact name. * Dealing with invalid sequences: By default, when a invalid UTF-8 sequence is identified, ext4 will treat it as an opaque byte sequence, ignoring the encoding and reverting to the old behavior for that unique file. This means that case-insensitive file name lookup will not work only for that file. An optional bit can be set in the superblock telling the filesystem code and userspace tools to enforce the encoding. When that optional bit is set, any attempt to create a file name using an invalid UTF-8 sequence will fail and return an error to userspace. * Normalization algorithm: The UTF-8 algorithms used to compare strings in ext4 is implemented lives in fs/unicode, and is based on a previous version developed by SGI. It implements the Canonical decomposition (NFD) algorithm described by the Unicode specification 12.1, or higher, combined with the elimination of ignorable code points (NFDi) and full case-folding (CF) as documented in fs/unicode/utf8_norm.c. NFD seems to be the best normalization method for EXT4 because: - It has a lower cost than NFC/NFKC (which requires decomposing to NFD as an intermediary step) - It doesn't eliminate important semantic meaning like compatibility decompositions. Although: - This implementation is not completely linguistic accurate, because different languages have conflicting rules, which would require the specialization of the filesystem to a given locale, which brings all sorts of problems for removable media and for users who use more than one language. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-25 18:12:08 +00:00
ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
parent_group = hinfo.hash % ngroups;
} else
parent_group = get_random_u32_below(ngroups);
for (i = 0; i < ngroups; i++) {
g = (parent_group + i) % ngroups;
get_orlov_stats(sb, g, flex_size, &stats);
if (!stats.free_inodes)
continue;
if (stats.used_dirs >= best_ndir)
continue;
if (stats.free_inodes < avefreei)
continue;
if (stats.free_clusters < avefreec)
continue;
grp = g;
ret = 0;
best_ndir = stats.used_dirs;
}
if (ret)
goto fallback;
found_flex_bg:
if (flex_size == 1) {
*group = grp;
return 0;
}
/*
* We pack inodes at the beginning of the flexgroup's
* inode tables. Block allocation decisions will do
* something similar, although regular files will
* start at 2nd block group of the flexgroup. See
* ext4_ext_find_goal() and ext4_find_near().
*/
grp *= flex_size;
for (i = 0; i < flex_size; i++) {
if (grp+i >= real_ngroups)
break;
desc = ext4_get_group_desc(sb, grp+i, NULL);
if (desc && ext4_free_inodes_count(sb, desc)) {
*group = grp+i;
return 0;
}
}
goto fallback;
}
max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
min_inodes = avefreei - inodes_per_group*flex_size / 4;
if (min_inodes < 1)
min_inodes = 1;
min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
if (min_clusters < 0)
min_clusters = 0;
/*
* Start looking in the flex group where we last allocated an
* inode for this parent directory
*/
if (EXT4_I(parent)->i_last_alloc_group != ~0) {
parent_group = EXT4_I(parent)->i_last_alloc_group;
if (flex_size > 1)
parent_group >>= sbi->s_log_groups_per_flex;
}
for (i = 0; i < ngroups; i++) {
grp = (parent_group + i) % ngroups;
get_orlov_stats(sb, grp, flex_size, &stats);
if (stats.used_dirs >= max_dirs)
continue;
if (stats.free_inodes < min_inodes)
continue;
if (stats.free_clusters < min_clusters)
continue;
goto found_flex_bg;
}
fallback:
ngroups = real_ngroups;
avefreei = freei / ngroups;
fallback_retry:
parent_group = EXT4_I(parent)->i_block_group;
for (i = 0; i < ngroups; i++) {
grp = (parent_group + i) % ngroups;
desc = ext4_get_group_desc(sb, grp, NULL);
if (desc) {
grp_free = ext4_free_inodes_count(sb, desc);
if (grp_free && grp_free >= avefreei) {
*group = grp;
return 0;
}
}
}
if (avefreei) {
/*
* The free-inodes counter is approximate, and for really small
* filesystems the above test can fail to find any blockgroups
*/
avefreei = 0;
goto fallback_retry;
}
return -1;
}
static int find_group_other(struct super_block *sb, struct inode *parent,
ext4_group_t *group, umode_t mode)
{
ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
struct ext4_group_desc *desc;
int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
/*
* Try to place the inode is the same flex group as its
* parent. If we can't find space, use the Orlov algorithm to
* find another flex group, and store that information in the
* parent directory's inode information so that use that flex
* group for future allocations.
*/
if (flex_size > 1) {
int retry = 0;
try_again:
parent_group &= ~(flex_size-1);
last = parent_group + flex_size;
if (last > ngroups)
last = ngroups;
for (i = parent_group; i < last; i++) {
desc = ext4_get_group_desc(sb, i, NULL);
if (desc && ext4_free_inodes_count(sb, desc)) {
*group = i;
return 0;
}
}
if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
retry = 1;
parent_group = EXT4_I(parent)->i_last_alloc_group;
goto try_again;
}
/*
* If this didn't work, use the Orlov search algorithm
* to find a new flex group; we pass in the mode to
* avoid the topdir algorithms.
*/
*group = parent_group + flex_size;
if (*group > ngroups)
*group = 0;
return find_group_orlov(sb, parent, group, mode, NULL);
}
/*
* Try to place the inode in its parent directory
*/
*group = parent_group;
desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && ext4_free_inodes_count(sb, desc) &&
ext4_free_group_clusters(sb, desc))
return 0;
/*
* We're going to place this inode in a different blockgroup from its
* parent. We want to cause files in a common directory to all land in
* the same blockgroup. But we want files which are in a different
* directory which shares a blockgroup with our parent to land in a
* different blockgroup.
*
* So add our directory's i_ino into the starting point for the hash.
*/
*group = (*group + parent->i_ino) % ngroups;
/*
* Use a quadratic hash to find a group with a free inode and some free
* blocks.
*/
for (i = 1; i < ngroups; i <<= 1) {
*group += i;
if (*group >= ngroups)
*group -= ngroups;
desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && ext4_free_inodes_count(sb, desc) &&
ext4_free_group_clusters(sb, desc))
return 0;
}
/*
* That failed: try linear search for a free inode, even if that group
* has no free blocks.
*/
*group = parent_group;
for (i = 0; i < ngroups; i++) {
if (++*group >= ngroups)
*group = 0;
desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && ext4_free_inodes_count(sb, desc))
return 0;
}
return -1;
}
/*
* In no journal mode, if an inode has recently been deleted, we want
* to avoid reusing it until we're reasonably sure the inode table
* block has been written back to disk. (Yes, these values are
* somewhat arbitrary...)
*/
#define RECENTCY_MIN 60
#define RECENTCY_DIRTY 300
static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
{
struct ext4_group_desc *gdp;
struct ext4_inode *raw_inode;
struct buffer_head *bh;
int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
int offset, ret = 0;
int recentcy = RECENTCY_MIN;
u32 dtime, now;
gdp = ext4_get_group_desc(sb, group, NULL);
if (unlikely(!gdp))
return 0;
bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
(ino / inodes_per_block));
if (!bh || !buffer_uptodate(bh))
/*
* If the block is not in the buffer cache, then it
* must have been written out.
*/
goto out;
offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
raw_inode = (struct ext4_inode *) (bh->b_data + offset);
/* i_dtime is only 32 bits on disk, but we only care about relative
* times in the range of a few minutes (i.e. long enough to sync a
* recently-deleted inode to disk), so using the low 32 bits of the
* clock (a 68 year range) is enough, see time_before32() */
dtime = le32_to_cpu(raw_inode->i_dtime);
now = ktime_get_real_seconds();
if (buffer_dirty(bh))
recentcy += RECENTCY_DIRTY;
if (dtime && time_before32(dtime, now) &&
time_before32(now, dtime + recentcy))
ret = 1;
out:
brelse(bh);
return ret;
}
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
static int find_inode_bit(struct super_block *sb, ext4_group_t group,
struct buffer_head *bitmap, unsigned long *ino)
{
bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;
unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
next:
*ino = ext4_find_next_zero_bit((unsigned long *)
bitmap->b_data,
EXT4_INODES_PER_GROUP(sb), *ino);
if (*ino >= EXT4_INODES_PER_GROUP(sb))
goto not_found;
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
if (check_recently_deleted && recently_deleted(sb, group, *ino)) {
recently_deleted_ino = *ino;
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
*ino = *ino + 1;
if (*ino < EXT4_INODES_PER_GROUP(sb))
goto next;
goto not_found;
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
}
return 1;
not_found:
if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))
return 0;
/*
* Not reusing recently deleted inodes is mostly a preference. We don't
* want to report ENOSPC or skew allocation patterns because of that.
* So return even recently deleted inode if we could find better in the
* given range.
*/
*ino = recently_deleted_ino;
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
return 1;
}
int ext4_mark_inode_used(struct super_block *sb, int ino)
{
unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
struct buffer_head *inode_bitmap_bh = NULL, *group_desc_bh = NULL;
struct ext4_group_desc *gdp;
ext4_group_t group;
int bit;
int err;
if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
return -EFSCORRUPTED;
group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
if (IS_ERR(inode_bitmap_bh))
return PTR_ERR(inode_bitmap_bh);
if (ext4_test_bit(bit, inode_bitmap_bh->b_data)) {
err = 0;
goto out;
}
gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
if (!gdp) {
err = -EINVAL;
goto out;
}
ext4_set_bit(bit, inode_bitmap_bh->b_data);
BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(NULL, NULL, inode_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
err = sync_dirty_buffer(inode_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
/* We may have to initialize the block bitmap if it isn't already */
if (ext4_has_group_desc_csum(sb) &&
gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
struct buffer_head *block_bitmap_bh;
block_bitmap_bh = ext4_read_block_bitmap(sb, group);
if (IS_ERR(block_bitmap_bh)) {
err = PTR_ERR(block_bitmap_bh);
goto out;
}
BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
err = ext4_handle_dirty_metadata(NULL, NULL, block_bitmap_bh);
sync_dirty_buffer(block_bitmap_bh);
/* recheck and clear flag under lock if we still need to */
ext4_lock_group(sb, group);
if (ext4_has_group_desc_csum(sb) &&
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
ext4_free_group_clusters_set(sb, gdp,
ext4_free_clusters_after_init(sb, group, gdp));
ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);
ext4_group_desc_csum_set(sb, group, gdp);
}
ext4_unlock_group(sb, group);
brelse(block_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
}
/* Update the relevant bg descriptor fields */
if (ext4_has_group_desc_csum(sb)) {
int free;
ext4_lock_group(sb, group); /* while we modify the bg desc */
free = EXT4_INODES_PER_GROUP(sb) -
ext4_itable_unused_count(sb, gdp);
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
free = 0;
}
/*
* Check the relative inode number against the last used
* relative inode number in this group. if it is greater
* we need to update the bg_itable_unused count
*/
if (bit >= free)
ext4_itable_unused_set(sb, gdp,
(EXT4_INODES_PER_GROUP(sb) - bit - 1));
} else {
ext4_lock_group(sb, group);
}
ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
if (ext4_has_group_desc_csum(sb)) {
ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);
ext4_group_desc_csum_set(sb, group, gdp);
}
ext4_unlock_group(sb, group);
err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
sync_dirty_buffer(group_desc_bh);
out:
brelse(inode_bitmap_bh);
return err;
}
static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
bool encrypt)
{
struct super_block *sb = dir->i_sb;
int nblocks = 0;
#ifdef CONFIG_EXT4_FS_POSIX_ACL
fs: rename current get acl method The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. The current inode operation for getting posix acls takes an inode argument but various filesystems (e.g., 9p, cifs, overlayfs) need access to the dentry. In contrast to the ->set_acl() inode operation we cannot simply extend ->get_acl() to take a dentry argument. The ->get_acl() inode operation is called from: acl_permission_check() -> check_acl() -> get_acl() which is part of generic_permission() which in turn is part of inode_permission(). Both generic_permission() and inode_permission() are called in the ->permission() handler of various filesystems (e.g., overlayfs). So simply passing a dentry argument to ->get_acl() would amount to also having to pass a dentry argument to ->permission(). We should avoid this unnecessary change. So instead of extending the existing inode operation rename it from ->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that passes a dentry argument and which filesystems that need access to the dentry can implement instead of ->get_inode_acl(). Filesystems like cifs which allow setting and getting posix acls but not using them for permission checking during lookup can simply not implement ->get_inode_acl(). This is intended to be a non-functional change. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-09-22 15:17:00 +00:00
struct posix_acl *p = get_inode_acl(dir, ACL_TYPE_DEFAULT);
if (IS_ERR(p))
return PTR_ERR(p);
if (p) {
int acl_size = p->a_count * sizeof(ext4_acl_entry);
nblocks += (S_ISDIR(mode) ? 2 : 1) *
__ext4_xattr_set_credits(sb, NULL /* inode */,
NULL /* block_bh */, acl_size,
true /* is_create */);
posix_acl_release(p);
}
#endif
#ifdef CONFIG_SECURITY
{
int num_security_xattrs = 1;
#ifdef CONFIG_INTEGRITY
num_security_xattrs++;
#endif
/*
* We assume that security xattrs are never more than 1k.
* In practice they are under 128 bytes.
*/
nblocks += num_security_xattrs *
__ext4_xattr_set_credits(sb, NULL /* inode */,
NULL /* block_bh */, 1024,
true /* is_create */);
}
#endif
if (encrypt)
nblocks += __ext4_xattr_set_credits(sb,
NULL /* inode */,
NULL /* block_bh */,
FSCRYPT_SET_CONTEXT_MAX_SIZE,
true /* is_create */);
return nblocks;
}
/*
* There are two policies for allocating an inode. If the new inode is
* a directory, then a forward search is made for a block group with both
* free space and a low directory-to-inode ratio; if that fails, then of
* the groups with above-average free space, that group with the fewest
* directories already is chosen.
*
* For other inodes, search forward from the parent directory's block
* group to find a free inode.
*/
struct inode *__ext4_new_inode(struct mnt_idmap *idmap,
ext4: support idmapped mounts Enable idmapped mounts for ext4. All dedicated helpers we need for this exist. So this basically just means we're passing down the user_namespace argument from the VFS methods to the relevant helpers. Let's create simple example where we idmap an ext4 filesystem: root@f2-vm:~# truncate -s 5G ext4.img root@f2-vm:~# mkfs.ext4 ./ext4.img mke2fs 1.45.5 (07-Jan-2020) Discarding device blocks: done Creating filesystem with 1310720 4k blocks and 327680 inodes Filesystem UUID: 3fd91794-c6ca-4b0f-9964-289a000919cf Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736 Allocating group tables: done Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: done root@f2-vm:~# losetup -f --show ./ext4.img /dev/loop0 root@f2-vm:~# mount /dev/loop0 /mnt root@f2-vm:~# ls -al /mnt/ total 24 drwxr-xr-x 3 root root 4096 Oct 28 13:34 . drwxr-xr-x 30 root root 4096 Oct 28 13:22 .. drwx------ 2 root root 16384 Oct 28 13:34 lost+found # Let's create an idmapped mount at /idmapped1 where we map uid and gid # 0 to uid and gid 1000 root@f2-vm:/# ./mount-idmapped --map-mount b:0:1000:1 /mnt/ /idmapped1/ root@f2-vm:/# ls -al /idmapped1/ total 24 drwxr-xr-x 3 ubuntu ubuntu 4096 Oct 28 13:34 . drwxr-xr-x 30 root root 4096 Oct 28 13:22 .. drwx------ 2 ubuntu ubuntu 16384 Oct 28 13:34 lost+found # Let's create an idmapped mount at /idmapped2 where we map uid and gid # 0 to uid and gid 2000 root@f2-vm:/# ./mount-idmapped --map-mount b:0:2000:1 /mnt/ /idmapped2/ root@f2-vm:/# ls -al /idmapped2/ total 24 drwxr-xr-x 3 2000 2000 4096 Oct 28 13:34 . drwxr-xr-x 31 root root 4096 Oct 28 13:39 .. drwx------ 2 2000 2000 16384 Oct 28 13:34 lost+found Let's create another example where we idmap the rootfs filesystem without a mapping for uid 0 and gid 0: # Create an idmapped mount of for a full POSIX range of rootfs under # /mnt but without a mapping for uid 0 to reduce attack surface root@f2-vm:/# ./mount-idmapped --map-mount b:1:1:65536 / /mnt/ # Since we don't have a mapping for uid and gid 0 all files owned by # uid and gid 0 should show up as uid and gid 65534: root@f2-vm:/# ls -al /mnt/ total 664 drwxr-xr-x 31 nobody nogroup 4096 Oct 28 13:39 . drwxr-xr-x 31 root root 4096 Oct 28 13:39 .. lrwxrwxrwx 1 nobody nogroup 7 Aug 25 07:44 bin -> usr/bin drwxr-xr-x 4 nobody nogroup 4096 Oct 28 13:17 boot drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:48 dev drwxr-xr-x 81 nobody nogroup 4096 Oct 28 04:00 etc drwxr-xr-x 4 nobody nogroup 4096 Oct 28 04:00 home lrwxrwxrwx 1 nobody nogroup 7 Aug 25 07:44 lib -> usr/lib lrwxrwxrwx 1 nobody nogroup 9 Aug 25 07:44 lib32 -> usr/lib32 lrwxrwxrwx 1 nobody nogroup 9 Aug 25 07:44 lib64 -> usr/lib64 lrwxrwxrwx 1 nobody nogroup 10 Aug 25 07:44 libx32 -> usr/libx32 drwx------ 2 nobody nogroup 16384 Aug 25 07:47 lost+found drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 media drwxr-xr-x 31 nobody nogroup 4096 Oct 28 13:39 mnt drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 opt drwxr-xr-x 2 nobody nogroup 4096 Apr 15 2020 proc drwx--x--x 6 nobody nogroup 4096 Oct 28 13:34 root drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:46 run lrwxrwxrwx 1 nobody nogroup 8 Aug 25 07:44 sbin -> usr/sbin drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 srv drwxr-xr-x 2 nobody nogroup 4096 Apr 15 2020 sys drwxrwxrwt 10 nobody nogroup 4096 Oct 28 13:19 tmp drwxr-xr-x 14 nobody nogroup 4096 Oct 20 13:00 usr drwxr-xr-x 12 nobody nogroup 4096 Aug 25 07:45 var # Since we do have a mapping for uid and gid 1000 all files owned by # uid and gid 1000 should simply show up as uid and gid 1000: root@f2-vm:/# ls -al /mnt/home/ubuntu/ total 40 drwxr-xr-x 3 ubuntu ubuntu 4096 Oct 28 00:43 . drwxr-xr-x 4 nobody nogroup 4096 Oct 28 04:00 .. -rw------- 1 ubuntu ubuntu 2936 Oct 28 12:26 .bash_history -rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout -rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc -rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile -rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful -rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo Link: https://lore.kernel.org/r/20210121131959.646623-39-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-ext4@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-21 13:19:57 +00:00
handle_t *handle, struct inode *dir,
umode_t mode, const struct qstr *qstr,
ext4: do not set posix acls on xattr inodes We don't need acls on xattr inodes because they are not directly accessible from user mode. Besides lockdep complains about recursive locking of xattr_sem as seen below. ============================================= [ INFO: possible recursive locking detected ] 4.11.0-rc8+ #402 Not tainted --------------------------------------------- python/1894 is trying to acquire lock: (&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270 but task is already holding lock: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ei->xattr_sem); lock(&ei->xattr_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by python/1894: #0: (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50 #1: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0 #2: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0 stack backtrace: CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x67/0x99 __lock_acquire+0x5f3/0x1830 lock_acquire+0xb5/0x1d0 down_read+0x2f/0x60 ext4_xattr_get+0x66/0x270 ext4_get_acl+0x43/0x1e0 get_acl+0x72/0xf0 posix_acl_create+0x5e/0x170 ext4_init_acl+0x21/0xc0 __ext4_new_inode+0xffd/0x16b0 ext4_xattr_set_entry+0x5ea/0xb70 ext4_xattr_block_set+0x1b5/0x970 ext4_xattr_set_handle+0x351/0x5d0 ext4_xattr_set+0x124/0x180 ext4_xattr_user_set+0x34/0x40 __vfs_setxattr+0x66/0x80 __vfs_setxattr_noperm+0x69/0x1c0 vfs_setxattr+0xa2/0xb0 setxattr+0x129/0x160 path_setxattr+0x87/0xb0 SyS_setxattr+0xf/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 01:21:39 +00:00
__u32 goal, uid_t *owner, __u32 i_flags,
int handle_type, unsigned int line_no,
int nblocks)
{
struct super_block *sb;
struct buffer_head *inode_bitmap_bh = NULL;
struct buffer_head *group_desc_bh;
ext4_group_t ngroups, group = 0;
unsigned long ino = 0;
struct inode *inode;
struct ext4_group_desc *gdp = NULL;
struct ext4_inode_info *ei;
struct ext4_sb_info *sbi;
int ret2, err;
struct inode *ret;
ext4_group_t i;
ext4_group_t flex_group;
struct ext4_group_info *grp = NULL;
bool encrypt = false;
/* Cannot create files in a deleted directory */
if (!dir || !dir->i_nlink)
return ERR_PTR(-EPERM);
sb = dir->i_sb;
sbi = EXT4_SB(sb);
if (unlikely(ext4_forced_shutdown(sb)))
return ERR_PTR(-EIO);
ngroups = ext4_get_groups_count(sb);
trace_ext4_request_inode(dir, mode);
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
ei = EXT4_I(inode);
/*
* Initialize owners and quota early so that we don't have to account
* for quota initialization worst case in standard inode creating
* transaction
*/
if (owner) {
inode->i_mode = mode;
i_uid_write(inode, owner[0]);
i_gid_write(inode, owner[1]);
} else if (test_opt(sb, GRPID)) {
inode->i_mode = mode;
inode_fsuid_set(inode, idmap);
inode->i_gid = dir->i_gid;
} else
inode_init_owner(idmap, inode, dir, mode);
if (ext4_has_feature_project(sb) &&
ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
ei->i_projid = EXT4_I(dir)->i_projid;
else
ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
if (!(i_flags & EXT4_EA_INODE_FL)) {
err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
if (err)
goto out;
}
err = dquot_initialize(inode);
if (err)
goto out;
if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);
if (ret2 < 0) {
err = ret2;
goto out;
}
nblocks += ret2;
}
if (!goal)
goal = sbi->s_inode_goal;
if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
ret2 = 0;
goto got_group;
}
if (S_ISDIR(mode))
ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
else
ret2 = find_group_other(sb, dir, &group, mode);
got_group:
EXT4_I(dir)->i_last_alloc_group = group;
err = -ENOSPC;
if (ret2 == -1)
goto out;
/*
* Normally we will only go through one pass of this loop,
* unless we get unlucky and it turns out the group we selected
* had its last inode grabbed by someone else.
*/
for (i = 0; i < ngroups; i++, ino = 0) {
err = -EIO;
gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
if (!gdp)
goto out;
/*
* Check free inodes count before loading bitmap.
*/
if (ext4_free_inodes_count(sb, gdp) == 0)
goto next_group;
if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
grp = ext4_get_group_info(sb, group);
/*
* Skip groups with already-known suspicious inode
* tables
*/
ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2023-04-29 04:06:28 +00:00
if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
goto next_group;
}
brelse(inode_bitmap_bh);
inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
/* Skip groups with suspicious inode tables */
if (IS_ERR(inode_bitmap_bh)) {
inode_bitmap_bh = NULL;
goto next_group;
}
if (!(sbi->s_mount_state & EXT4_FC_REPLAY) &&
EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
goto next_group;
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
if (!ret2)
goto next_group;
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
ext4_error(sb, "reserved inode found cleared - "
"inode=%lu", ino + 1);
ext4_mark_group_bitmap_corrupted(sb, group,
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
goto next_group;
}
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
BUG_ON(nblocks <= 0);
handle = __ext4_journal_start_sb(NULL, dir->i_sb,
line_no, handle_type, nblocks, 0,
ext4: reserve revoke credits in __ext4_new_inode It's possible that __ext4_new_inode will release the xattr block, so it will trigger a warning since there is revoke credits will be 0 if the handle == NULL. The below scripts can reproduce it easily. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 3861 at fs/jbd2/revoke.c:374 jbd2_journal_revoke+0x30e/0x540 fs/jbd2/revoke.c:374 ... __ext4_forget+0x1d7/0x800 fs/ext4/ext4_jbd2.c:248 ext4_free_blocks+0x213/0x1d60 fs/ext4/mballoc.c:4743 ext4_xattr_release_block+0x55b/0x780 fs/ext4/xattr.c:1254 ext4_xattr_block_set+0x1c2c/0x2c40 fs/ext4/xattr.c:2112 ext4_xattr_set_handle+0xa7e/0x1090 fs/ext4/xattr.c:2384 __ext4_set_acl+0x54d/0x6c0 fs/ext4/acl.c:214 ext4_init_acl+0x218/0x2e0 fs/ext4/acl.c:293 __ext4_new_inode+0x352a/0x42b0 fs/ext4/ialloc.c:1151 ext4_mkdir+0x2e9/0xbd0 fs/ext4/namei.c:2774 vfs_mkdir+0x386/0x5f0 fs/namei.c:3811 do_mkdirat+0x11c/0x210 fs/namei.c:3834 do_syscall_64+0xa1/0x530 arch/x86/entry/common.c:294 ... ------------------------------------- scripts: mkfs.ext4 /dev/vdb mount /dev/vdb /mnt cd /mnt && mkdir dir && for i in {1..8}; do setfacl -dm "u:user_"$i":rx" dir; done mkdir dir/dir1 && mv dir/dir1 ./ sh repro.sh && add some user [root@localhost ~]# cat repro.sh while [ 1 -eq 1 ]; do rm -rf dir rm -rf dir1/dir1 mkdir dir for i in {1..8}; do setfacl -dm "u:test"$i":rx" dir; done setfacl -m "u:user_9:rx" dir & mkdir dir1/dir1 & done Before exec repro.sh, dir1 has inherit the default acl from dir, and xattr block of dir1 dir is not the same, so the h_refcount of these two dir's xattr block will be 1. Then repro.sh can trigger the warning with the situation show as below. The last h_refcount can be clear with mkdir, and __ext4_new_inode has not reserved revoke credits, so the warning will happened, fix it by reserve revoke credits in __ext4_new_inode. Thread 1 Thread 2 mkdir dir set default acl(will create a xattr block blk1 and the refcount of ext4_xattr_header will be 1) ... mkdir dir1/dir1 ->....->ext4_init_acl ->__ext4_set_acl(set default acl, will reuse blk1, and h_refcount will be 2) setfacl->ext4_set_acl->... ->ext4_xattr_block_set(will create new block blk2 to store xattr) ->__ext4_set_acl(set access acl, since h_refcount of blk1 is 2, will create blk3 to store xattr) ->ext4_xattr_release_block(dec h_refcount of blk1 to 1) ->ext4_xattr_release_block(dec h_refcount and since it is 0, will release the block and trigger the warning) Link: https://lore.kernel.org/r/20191213014900.47228-1-yangerkun@huawei.com Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-12-13 01:49:00 +00:00
ext4_trans_default_revoke_credits(sb));
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
ext4_std_error(sb, err);
goto out;
}
}
BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,
EXT4_JTR_NONE);
if (err) {
ext4_std_error(sb, err);
goto out;
}
ext4_lock_group(sb, group);
ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
if (ret2) {
/* Someone already took the bit. Repeat the search
* with lock held.
*/
ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
if (ret2) {
ext4_set_bit(ino, inode_bitmap_bh->b_data);
ret2 = 0;
} else {
ret2 = 1; /* we didn't grab the inode */
}
}
ext4_unlock_group(sb, group);
ino++; /* the inode bitmap is zero-based */
if (!ret2)
goto got; /* we grabbed the inode! */
ext4: reduce lock contention in __ext4_new_inode While running number of creating file threads concurrently, we found heavy lock contention on group spinlock: FUNC TOTAL_TIME(us) COUNT AVG(us) ext4_create 1707443399 1440000 1185.72 _raw_spin_lock 1317641501 180899929 7.28 jbd2__journal_start 287821030 1453950 197.96 jbd2_journal_get_write_access 33441470 73077185 0.46 ext4_add_nondir 29435963 1440000 20.44 ext4_add_entry 26015166 1440049 18.07 ext4_dx_add_entry 25729337 1432814 17.96 ext4_mark_inode_dirty 12302433 5774407 2.13 most of cpu time blames to _raw_spin_lock, here is some testing numbers with/without patch. Test environment: Server : SuperMicro Sever (2 x E5-2690 v3@2.60GHz, 128GB 2133MHz DDR4 Memory, 8GbFC) Storage : 2 x RAID1 (DDN SFA7700X, 4 x Toshiba PX02SMU020 200GB Read Intensive SSD) format command: mkfs.ext4 -J size=4096 test command: mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 1 -v -p 10 -u #first run to load inode mpirun -np 48 mdtest -n 30000 -d /ext4/mdtest.out -F -C \ -r -i 3 -v -p 10 -u Kernel version: 4.13.0-rc3 Test 1,440,000 files with 48 directories by 48 processes: Without patch: File Creation File removal 79,033 289,569 ops/per second 81,463 285,359 79,875 288,475 With patch: File Creation File removal 810669 301694 812805 302711 813965 297670 Creation performance is improved more than 10X with large journal size. The main problem here is we test bitmap and do some check and journal operations which could be slept, then we test and set with lock hold, this could be racy, and make 'inode' steal by other process. However, after first try, we could confirm handle has been started and inode bitmap journaled too, then we could find and set bit with lock hold directly, this will mostly gurateee success with second try. Tested-by: Shuichi Ihara <sihara@ddn.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-08-24 16:56:35 +00:00
next_group:
if (++group == ngroups)
group = 0;
}
err = -ENOSPC;
goto out;
got:
BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
BUFFER_TRACE(group_desc_bh, "get_write_access");
err = ext4_journal_get_write_access(handle, sb, group_desc_bh,
EXT4_JTR_NONE);
if (err) {
ext4_std_error(sb, err);
goto out;
}
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
/* We may have to initialize the block bitmap if it isn't already */
if (ext4_has_group_desc_csum(sb) &&
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
struct buffer_head *block_bitmap_bh;
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
block_bitmap_bh = ext4_read_block_bitmap(sb, group);
if (IS_ERR(block_bitmap_bh)) {
err = PTR_ERR(block_bitmap_bh);
goto out;
}
BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
err = ext4_journal_get_write_access(handle, sb, block_bitmap_bh,
EXT4_JTR_NONE);
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
if (err) {
brelse(block_bitmap_bh);
ext4_std_error(sb, err);
goto out;
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
}
BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
/* recheck and clear flag under lock if we still need to */
ext4_lock_group(sb, group);
if (ext4_has_group_desc_csum(sb) &&
(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
ext4_free_group_clusters_set(sb, gdp,
ext4_free_clusters_after_init(sb, group, gdp));
ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);
ext4_group_desc_csum_set(sb, group, gdp);
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
}
ext4_unlock_group(sb, group);
brelse(block_bitmap_bh);
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
if (err) {
ext4_std_error(sb, err);
goto out;
}
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
}
/* Update the relevant bg descriptor fields */
if (ext4_has_group_desc_csum(sb)) {
int free;
struct ext4_group_info *grp = NULL;
if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
grp = ext4_get_group_info(sb, group);
ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2023-04-29 04:06:28 +00:00
if (!grp) {
err = -EFSCORRUPTED;
goto out;
}
down_read(&grp->alloc_sem); /*
* protect vs itable
* lazyinit
*/
}
ext4_lock_group(sb, group); /* while we modify the bg desc */
free = EXT4_INODES_PER_GROUP(sb) -
ext4_itable_unused_count(sb, gdp);
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
free = 0;
}
/*
* Check the relative inode number against the last used
* relative inode number in this group. if it is greater
* we need to update the bg_itable_unused count
*/
if (ino > free)
ext4_itable_unused_set(sb, gdp,
(EXT4_INODES_PER_GROUP(sb) - ino));
if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
up_read(&grp->alloc_sem);
} else {
ext4_lock_group(sb, group);
}
ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
if (S_ISDIR(mode)) {
ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
if (sbi->s_log_groups_per_flex) {
ext4_group_t f = ext4_flex_group(sbi, group);
atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
f)->used_dirs);
}
}
if (ext4_has_group_desc_csum(sb)) {
ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);
ext4_group_desc_csum_set(sb, group, gdp);
}
ext4_unlock_group(sb, group);
BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
if (err) {
ext4_std_error(sb, err);
goto out;
}
percpu_counter_dec(&sbi->s_freeinodes_counter);
if (S_ISDIR(mode))
percpu_counter_inc(&sbi->s_dirs_counter);
if (sbi->s_log_groups_per_flex) {
flex_group = ext4_flex_group(sbi, group);
atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
flex_group)->free_inodes);
}
Ext4: Uninitialized Block Groups In pass1 of e2fsck, every inode table in the fileystem is scanned and checked, regardless of whether it is in use. This is this the most time consuming part of the filesystem check. The unintialized block group feature can greatly reduce e2fsck time by eliminating checking of uninitialized inodes. With this feature, there is a a high water mark of used inodes for each block group. Block and inode bitmaps can be uninitialized on disk via a flag in the group descriptor to avoid reading or scanning them at e2fsck time. A checksum of each group descriptor is used to ensure that corruption in the group descriptor's bit flags does not cause incorrect operation. The feature is enabled through a mkfs option mke2fs /dev/ -O uninit_groups A patch adding support for uninitialized block groups to e2fsprogs tools has been posted to the linux-ext4 mailing list. The patches have been stress tested with fsstress and fsx. In performance tests testing e2fsck time, we have seen that e2fsck time on ext3 grows linearly with the total number of inodes in the filesytem. In ext4 with the uninitialized block groups feature, the e2fsck time is constant, based solely on the number of used inodes rather than the total inode count. Since typical ext4 filesystems only use 1-10% of their inodes, this feature can greatly reduce e2fsck time for users. With performance improvement of 2-20 times, depending on how full the filesystem is. The attached graph shows the major improvements in e2fsck times in filesystems with a large total inode count, but few inodes in use. In each group descriptor if we have EXT4_BG_INODE_UNINIT set in bg_flags: Inode table is not initialized/used in this group. So we can skip the consistency check during fsck. EXT4_BG_BLOCK_UNINIT set in bg_flags: No block in the group is used. So we can skip the block bitmap verification for this group. We also add two new fields to group descriptor as a part of uninitialized group patch. __le16 bg_itable_unused; /* Unused inodes count */ __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */ bg_itable_unused: If we have EXT4_BG_INODE_UNINIT not set in bg_flags then bg_itable_unused will give the offset within the inode table till the inodes are used. This can be used by fsck to skip list of inodes that are marked unused. bg_checksum: Now that we depend on bg_flags and bg_itable_unused to determine the block and inode usage, we need to make sure group descriptor is not corrupt. We add checksum to group descriptor to detect corruption. If the descriptor is found to be corrupt, we mark all the blocks and inodes in the group used. Signed-off-by: Avantika Mathur <mathur@us.ibm.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2007-10-16 22:38:25 +00:00
inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
/* This is the optimal IO size (for stat), not the fs block size */
inode->i_blocks = 0;
simple_inode_init_ts(inode);
ei->i_crtime = inode_get_mtime(inode);
memset(ei->i_data, 0, sizeof(ei->i_data));
ei->i_dir_start_lookup = 0;
ei->i_disksize = 0;
/* Don't inherit extent flag from directory, amongst others. */
ei->i_flags =
ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
ext4: do not set posix acls on xattr inodes We don't need acls on xattr inodes because they are not directly accessible from user mode. Besides lockdep complains about recursive locking of xattr_sem as seen below. ============================================= [ INFO: possible recursive locking detected ] 4.11.0-rc8+ #402 Not tainted --------------------------------------------- python/1894 is trying to acquire lock: (&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270 but task is already holding lock: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ei->xattr_sem); lock(&ei->xattr_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by python/1894: #0: (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50 #1: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0 #2: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0 stack backtrace: CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x67/0x99 __lock_acquire+0x5f3/0x1830 lock_acquire+0xb5/0x1d0 down_read+0x2f/0x60 ext4_xattr_get+0x66/0x270 ext4_get_acl+0x43/0x1e0 get_acl+0x72/0xf0 posix_acl_create+0x5e/0x170 ext4_init_acl+0x21/0xc0 __ext4_new_inode+0xffd/0x16b0 ext4_xattr_set_entry+0x5ea/0xb70 ext4_xattr_block_set+0x1b5/0x970 ext4_xattr_set_handle+0x351/0x5d0 ext4_xattr_set+0x124/0x180 ext4_xattr_user_set+0x34/0x40 __vfs_setxattr+0x66/0x80 __vfs_setxattr_noperm+0x69/0x1c0 vfs_setxattr+0xa2/0xb0 setxattr+0x129/0x160 path_setxattr+0x87/0xb0 SyS_setxattr+0xf/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 01:21:39 +00:00
ei->i_flags |= i_flags;
ei->i_file_acl = 0;
ei->i_dtime = 0;
ei->i_block_group = group;
ei->i_last_alloc_group = ~0;
ext4_set_inode_flags(inode, true);
if (IS_DIRSYNC(inode))
ext4_handle_sync(handle);
if (insert_inode_locked(inode) < 0) {
/*
* Likely a bitmap corruption causing inode to be allocated
* twice.
*/
err = -EIO;
ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
inode->i_ino);
ext4_mark_group_bitmap_corrupted(sb, group,
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
goto out;
}
inode->i_generation = get_random_u32();
/* Precompute checksum seed for inode metadata */
if (ext4_has_metadata_csum(sb)) {
__u32 csum;
__le32 inum = cpu_to_le32(inode->i_ino);
__le32 gen = cpu_to_le32(inode->i_generation);
csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
sizeof(inum));
ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
sizeof(gen));
}
ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
ext4_set_inode_state(inode, EXT4_STATE_NEW);
ei->i_extra_isize = sbi->s_want_extra_isize;
ei->i_inline_off = 0;
if (ext4_has_feature_inline_data(sb) &&
(!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
ret = inode;
err = dquot_alloc_inode(inode);
if (err)
goto fail_drop;
/*
* Since the encryption xattr will always be unique, create it first so
* that it's less likely to end up in an external xattr block and
* prevent its deduplication.
*/
if (encrypt) {
err = fscrypt_set_context(inode, handle);
if (err)
goto fail_free_drop;
}
ext4: do not set posix acls on xattr inodes We don't need acls on xattr inodes because they are not directly accessible from user mode. Besides lockdep complains about recursive locking of xattr_sem as seen below. ============================================= [ INFO: possible recursive locking detected ] 4.11.0-rc8+ #402 Not tainted --------------------------------------------- python/1894 is trying to acquire lock: (&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270 but task is already holding lock: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ei->xattr_sem); lock(&ei->xattr_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by python/1894: #0: (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50 #1: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0 #2: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0 stack backtrace: CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x67/0x99 __lock_acquire+0x5f3/0x1830 lock_acquire+0xb5/0x1d0 down_read+0x2f/0x60 ext4_xattr_get+0x66/0x270 ext4_get_acl+0x43/0x1e0 get_acl+0x72/0xf0 posix_acl_create+0x5e/0x170 ext4_init_acl+0x21/0xc0 __ext4_new_inode+0xffd/0x16b0 ext4_xattr_set_entry+0x5ea/0xb70 ext4_xattr_block_set+0x1b5/0x970 ext4_xattr_set_handle+0x351/0x5d0 ext4_xattr_set+0x124/0x180 ext4_xattr_user_set+0x34/0x40 __vfs_setxattr+0x66/0x80 __vfs_setxattr_noperm+0x69/0x1c0 vfs_setxattr+0xa2/0xb0 setxattr+0x129/0x160 path_setxattr+0x87/0xb0 SyS_setxattr+0xf/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 01:21:39 +00:00
if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
err = ext4_init_acl(handle, inode, dir);
if (err)
goto fail_free_drop;
err = ext4_init_security(handle, inode, dir, qstr);
if (err)
goto fail_free_drop;
}
if (ext4_has_feature_extents(sb)) {
/* set extent flag only for directory, file and normal symlink*/
if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
ext4_ext_tree_init(handle, inode);
}
}
ext4_update_inode_fsync_trans(handle, inode, 1);
err = ext4_mark_inode_dirty(handle, inode);
if (err) {
ext4_std_error(sb, err);
goto fail_free_drop;
}
ext4_debug("allocating inode %lu\n", inode->i_ino);
trace_ext4_allocate_inode(inode, dir, mode);
brelse(inode_bitmap_bh);
return ret;
fail_free_drop:
dquot_free_inode(inode);
fail_drop:
clear_nlink(inode);
unlock_new_inode(inode);
out:
dquot_drop(inode);
inode->i_flags |= S_NOQUOTA;
iput(inode);
brelse(inode_bitmap_bh);
return ERR_PTR(err);
}
/* Verify that we are loading a valid orphan from disk */
struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
{
unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
ext4_group_t block_group;
int bit;
struct buffer_head *bitmap_bh = NULL;
struct inode *inode = NULL;
int err = -EFSCORRUPTED;
if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
goto bad_orphan;
block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
if (IS_ERR(bitmap_bh))
return ERR_CAST(bitmap_bh);
/* Having the inode bit set should be a 100% indicator that this
* is a valid orphan (no e2fsck run on fs). Orphans also include
* inodes that were being truncated, so we can't check i_nlink==0.
*/
if (!ext4_test_bit(bit, bitmap_bh->b_data))
goto bad_orphan;
inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
ext4_error_err(sb, -err,
"couldn't read orphan inode %lu (err %d)",
ino, err);
brelse(bitmap_bh);
return inode;
}
/*
* If the orphans has i_nlinks > 0 then it should be able to
* be truncated, otherwise it won't be removed from the orphan
* list during processing and an infinite loop will result.
* Similarly, it must not be a bad inode.
*/
if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
is_bad_inode(inode))
goto bad_orphan;
if (NEXT_ORPHAN(inode) > max_ino)
goto bad_orphan;
brelse(bitmap_bh);
return inode;
bad_orphan:
ext4_error(sb, "bad orphan inode %lu", ino);
if (bitmap_bh)
printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
bit, (unsigned long long)bitmap_bh->b_blocknr,
ext4_test_bit(bit, bitmap_bh->b_data));
if (inode) {
printk(KERN_ERR "is_bad_inode(inode)=%d\n",
is_bad_inode(inode));
printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
NEXT_ORPHAN(inode));
printk(KERN_ERR "max_ino=%lu\n", max_ino);
printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
/* Avoid freeing blocks if we got a bad deleted inode */
if (inode->i_nlink == 0)
inode->i_blocks = 0;
iput(inode);
}
brelse(bitmap_bh);
return ERR_PTR(err);
}
unsigned long ext4_count_free_inodes(struct super_block *sb)
{
unsigned long desc_count;
struct ext4_group_desc *gdp;
ext4_group_t i, ngroups = ext4_get_groups_count(sb);
#ifdef EXT4FS_DEBUG
struct ext4_super_block *es;
unsigned long bitmap_count, x;
struct buffer_head *bitmap_bh = NULL;
es = EXT4_SB(sb)->s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < ngroups; i++) {
gdp = ext4_get_group_desc(sb, i, NULL);
if (!gdp)
continue;
desc_count += ext4_free_inodes_count(sb, gdp);
brelse(bitmap_bh);
bitmap_bh = ext4_read_inode_bitmap(sb, i);
if (IS_ERR(bitmap_bh)) {
bitmap_bh = NULL;
continue;
}
x = ext4_count_free(bitmap_bh->b_data,
EXT4_INODES_PER_GROUP(sb) / 8);
printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
(unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
bitmap_count += x;
}
brelse(bitmap_bh);
printk(KERN_DEBUG "ext4_count_free_inodes: "
"stored = %u, computed = %lu, %lu\n",
le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
return desc_count;
#else
desc_count = 0;
for (i = 0; i < ngroups; i++) {
gdp = ext4_get_group_desc(sb, i, NULL);
if (!gdp)
continue;
desc_count += ext4_free_inodes_count(sb, gdp);
cond_resched();
}
return desc_count;
#endif
}
/* Called at mount-time, super-block is locked */
unsigned long ext4_count_dirs(struct super_block * sb)
{
unsigned long count = 0;
ext4_group_t i, ngroups = ext4_get_groups_count(sb);
for (i = 0; i < ngroups; i++) {
struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
if (!gdp)
continue;
count += ext4_used_dirs_count(sb, gdp);
}
return count;
}
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
/*
* Zeroes not yet zeroed inode table - just write zeroes through the whole
* inode table. Must be called without any spinlock held. The only place
* where it is called from on active part of filesystem is ext4lazyinit
* thread, so we do not need any special locks, however we have to prevent
* inode allocation from the current group, so we take alloc_sem lock, to
* block ext4_new_inode() until we are finished.
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
*/
int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
int barrier)
{
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_group_desc *gdp = NULL;
struct buffer_head *group_desc_bh;
handle_t *handle;
ext4_fsblk_t blk;
int num, ret = 0, used_blks = 0;
unsigned long used_inos = 0;
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2023-04-29 04:06:28 +00:00
if (!gdp || !grp)
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
goto out;
/*
* We do not need to lock this, because we are the only one
* handling this flag.
*/
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
goto out;
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
goto out;
}
down_write(&grp->alloc_sem);
/*
* If inode bitmap was already initialized there may be some
* used inodes so we need to skip blocks with used inodes in
* inode table.
*/
if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
used_inos = EXT4_INODES_PER_GROUP(sb) -
ext4_itable_unused_count(sb, gdp);
used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
/* Bogus inode unused count? */
if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
ext4_error(sb, "Something is wrong with group %u: "
"used itable blocks: %d; "
"itable unused count: %u",
group, used_blks,
ext4_itable_unused_count(sb, gdp));
ret = 1;
goto err_out;
}
used_inos += group * EXT4_INODES_PER_GROUP(sb);
/*
* Are there some uninitialized inodes in the inode table
* before the first normal inode?
*/
if ((used_blks != sbi->s_itb_per_group) &&
(used_inos < EXT4_FIRST_INO(sb))) {
ext4_error(sb, "Something is wrong with group %u: "
"itable unused count: %u; "
"itables initialized count: %ld",
group, ext4_itable_unused_count(sb, gdp),
used_inos);
ret = 1;
goto err_out;
}
}
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
blk = ext4_inode_table(sb, gdp) + used_blks;
num = sbi->s_itb_per_group - used_blks;
BUFFER_TRACE(group_desc_bh, "get_write_access");
ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,
EXT4_JTR_NONE);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
if (ret)
goto err_out;
/*
* Skip zeroout if the inode table is full. But we set the ZEROED
* flag anyway, because obviously, when it is full it does not need
* further zeroing.
*/
if (unlikely(num == 0))
goto skip_zeroout;
ext4_debug("going to zero out inode table in group %d\n",
group);
ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
if (ret < 0)
goto err_out;
if (barrier)
blkdev_issue_flush(sb->s_bdev);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
skip_zeroout:
ext4_lock_group(sb, group);
gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
ext4_group_desc_csum_set(sb, group, gdp);
ext4: add support for lazy inode table initialization When the lazy_itable_init extended option is passed to mke2fs, it considerably speeds up filesystem creation because inode tables are not zeroed out. The fact that parts of the inode table are uninitialized is not a problem so long as the block group descriptors, which contain information regarding how much of the inode table has been initialized, has not been corrupted However, if the block group checksums are not valid, e2fsck must scan the entire inode table, and the the old, uninitialized data could potentially cause e2fsck to report false problems. Hence, it is important for the inode tables to be initialized as soon as possble. This commit adds this feature so that mke2fs can safely use the lazy inode table initialization feature to speed up formatting file systems. This is done via a new new kernel thread called ext4lazyinit, which is created on demand and destroyed, when it is no longer needed. There is only one thread for all ext4 filesystems in the system. When the first filesystem with inititable mount option is mounted, ext4lazyinit thread is created, then the filesystem can register its request in the request list. This thread then walks through the list of requests picking up scheduled requests and invoking ext4_init_inode_table(). Next schedule time for the request is computed by multiplying the time it took to zero out last inode table with wait multiplier, which can be set with the (init_itable=n) mount option (default is 10). We are doing this so we do not take the whole I/O bandwidth. When the thread is no longer necessary (request list is empty) it frees the appropriate structures and exits (and can be created later later by another filesystem). We do not disturb regular inode allocations in any way, it just do not care whether the inode table is, or is not zeroed. But when zeroing, we have to skip used inodes, obviously. Also we should prevent new inode allocations from the group, while zeroing is on the way. For that we take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem in the ext4_claim_inode, so when we are unlucky and allocator hits the group which is currently being zeroed, it just has to wait. This can be suppresed using the mount option no_init_itable. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-28 01:30:05 +00:00
ext4_unlock_group(sb, group);
BUFFER_TRACE(group_desc_bh,
"call ext4_handle_dirty_metadata");
ret = ext4_handle_dirty_metadata(handle, NULL,
group_desc_bh);
err_out:
up_write(&grp->alloc_sem);
ext4_journal_stop(handle);
out:
return ret;
}