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linux/fs/ext4/namei.c
Arnd Bergmann 15eefe2a99 Merge branch 'vfs_timespec64' of https://github.com/deepa-hub/vfs into vfs-timespec64 
Pull the timespec64 conversion from Deepa Dinamani:
 "The series aims to switch vfs timestamps to use
  struct timespec64. Currently vfs uses struct timespec,
  which is not y2038 safe.

  The flag patch applies cleanly. I've not seen the timestamps
  update logic change often. The series applies cleanly on 4.17-rc6
  and linux-next tip (top commit: next-20180517).

  I'm not sure how to merge this kind of a series with a flag patch.
  We are targeting 4.18 for this.
  Let me know if you have other suggestions.

  The series involves the following:
  1. Add vfs helper functions for supporting struct timepec64 timestamps.
  2. Cast prints of vfs timestamps to avoid warnings after the switch.
  3. Simplify code using vfs timestamps so that the actual
     replacement becomes easy.
  4. Convert vfs timestamps to use struct timespec64 using a script.
     This is a flag day patch.

  I've tried to keep the conversions with the script simple, to
  aid in the reviews. I've kept all the internal filesystem data
  structures and function signatures the same.

  Next steps:
  1. Convert APIs that can handle timespec64, instead of converting
     timestamps at the boundaries.
  2. Update internal data structures to avoid timestamp conversions."

I've pulled it into a branch based on top of the NFS changes that
are now in mainline, so I could resolve the non-obvious conflict
between the two while merging.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-06-14 14:54:00 +02:00

3854 lines
101 KiB
C
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// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ext4/namei.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)
*
* from
*
* linux/fs/minix/namei.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
* Directory entry file type support and forward compatibility hooks
* for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
* Hash Tree Directory indexing (c)
* Daniel Phillips, 2001
* Hash Tree Directory indexing porting
* Christopher Li, 2002
* Hash Tree Directory indexing cleanup
* Theodore Ts'o, 2002
*/
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/time.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/bio.h>
#include <linux/iversion.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
#include <trace/events/ext4.h>
/*
* define how far ahead to read directories while searching them.
*/
#define NAMEI_RA_CHUNKS 2
#define NAMEI_RA_BLOCKS 4
#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
static struct buffer_head *ext4_append(handle_t *handle,
struct inode *inode,
ext4_lblk_t *block)
{
struct buffer_head *bh;
int err;
if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
((inode->i_size >> 10) >=
EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
return ERR_PTR(-ENOSPC);
*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
if (IS_ERR(bh))
return bh;
inode->i_size += inode->i_sb->s_blocksize;
EXT4_I(inode)->i_disksize = inode->i_size;
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err) {
brelse(bh);
ext4_std_error(inode->i_sb, err);
return ERR_PTR(err);
}
return bh;
}
static int ext4_dx_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent);
typedef enum {
EITHER, INDEX, DIRENT
} dirblock_type_t;
#define ext4_read_dirblock(inode, block, type) \
__ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
ext4_lblk_t block,
dirblock_type_t type,
const char *func,
unsigned int line)
{
struct buffer_head *bh;
struct ext4_dir_entry *dirent;
int is_dx_block = 0;
bh = ext4_bread(NULL, inode, block, 0);
if (IS_ERR(bh)) {
__ext4_warning(inode->i_sb, func, line,
"inode #%lu: lblock %lu: comm %s: "
"error %ld reading directory block",
inode->i_ino, (unsigned long)block,
current->comm, PTR_ERR(bh));
return bh;
}
if (!bh) {
ext4_error_inode(inode, func, line, block,
"Directory hole found");
return ERR_PTR(-EFSCORRUPTED);
}
dirent = (struct ext4_dir_entry *) bh->b_data;
/* Determine whether or not we have an index block */
if (is_dx(inode)) {
if (block == 0)
is_dx_block = 1;
else if (ext4_rec_len_from_disk(dirent->rec_len,
inode->i_sb->s_blocksize) ==
inode->i_sb->s_blocksize)
is_dx_block = 1;
}
if (!is_dx_block && type == INDEX) {
ext4_error_inode(inode, func, line, block,
"directory leaf block found instead of index block");
return ERR_PTR(-EFSCORRUPTED);
}
if (!ext4_has_metadata_csum(inode->i_sb) ||
buffer_verified(bh))
return bh;
/*
* An empty leaf block can get mistaken for a index block; for
* this reason, we can only check the index checksum when the
* caller is sure it should be an index block.
*/
if (is_dx_block && type == INDEX) {
if (ext4_dx_csum_verify(inode, dirent))
set_buffer_verified(bh);
else {
ext4_error_inode(inode, func, line, block,
"Directory index failed checksum");
brelse(bh);
return ERR_PTR(-EFSBADCRC);
}
}
if (!is_dx_block) {
if (ext4_dirent_csum_verify(inode, dirent))
set_buffer_verified(bh);
else {
ext4_error_inode(inode, func, line, block,
"Directory block failed checksum");
brelse(bh);
return ERR_PTR(-EFSBADCRC);
}
}
return bh;
}
#ifndef assert
#define assert(test) J_ASSERT(test)
#endif
#ifdef DX_DEBUG
#define dxtrace(command) command
#else
#define dxtrace(command)
#endif
struct fake_dirent
{
__le32 inode;
__le16 rec_len;
u8 name_len;
u8 file_type;
};
struct dx_countlimit
{
__le16 limit;
__le16 count;
};
struct dx_entry
{
__le32 hash;
__le32 block;
};
/*
* dx_root_info is laid out so that if it should somehow get overlaid by a
* dirent the two low bits of the hash version will be zero. Therefore, the
* hash version mod 4 should never be 0. Sincerely, the paranoia department.
*/
struct dx_root
{
struct fake_dirent dot;
char dot_name[4];
struct fake_dirent dotdot;
char dotdot_name[4];
struct dx_root_info
{
__le32 reserved_zero;
u8 hash_version;
u8 info_length; /* 8 */
u8 indirect_levels;
u8 unused_flags;
}
info;
struct dx_entry entries[0];
};
struct dx_node
{
struct fake_dirent fake;
struct dx_entry entries[0];
};
struct dx_frame
{
struct buffer_head *bh;
struct dx_entry *entries;
struct dx_entry *at;
};
struct dx_map_entry
{
u32 hash;
u16 offs;
u16 size;
};
/*
* This goes at the end of each htree block.
*/
struct dx_tail {
u32 dt_reserved;
__le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
};
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
static inline unsigned dx_get_hash(struct dx_entry *entry);
static void dx_set_hash(struct dx_entry *entry, unsigned value);
static unsigned dx_get_count(struct dx_entry *entries);
static unsigned dx_get_limit(struct dx_entry *entries);
static void dx_set_count(struct dx_entry *entries, unsigned value);
static void dx_set_limit(struct dx_entry *entries, unsigned value);
static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
static unsigned dx_node_limit(struct inode *dir);
static struct dx_frame *dx_probe(struct ext4_filename *fname,
struct inode *dir,
struct dx_hash_info *hinfo,
struct dx_frame *frame);
static void dx_release(struct dx_frame *frames);
static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
unsigned blocksize, struct dx_hash_info *hinfo,
struct dx_map_entry map[]);
static void dx_sort_map(struct dx_map_entry *map, unsigned count);
static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
struct dx_map_entry *offsets, int count, unsigned blocksize);
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
static void dx_insert_block(struct dx_frame *frame,
u32 hash, ext4_lblk_t block);
static int ext4_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frame,
struct dx_frame *frames,
__u32 *start_hash);
static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
struct ext4_filename *fname,
struct ext4_dir_entry_2 **res_dir);
static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
struct inode *dir, struct inode *inode);
/* checksumming functions */
void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
unsigned int blocksize)
{
memset(t, 0, sizeof(struct ext4_dir_entry_tail));
t->det_rec_len = ext4_rec_len_to_disk(
sizeof(struct ext4_dir_entry_tail), blocksize);
t->det_reserved_ft = EXT4_FT_DIR_CSUM;
}
/* Walk through a dirent block to find a checksum "dirent" at the tail */
static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
struct ext4_dir_entry *de)
{
struct ext4_dir_entry_tail *t;
#ifdef PARANOID
struct ext4_dir_entry *d, *top;
d = de;
top = (struct ext4_dir_entry *)(((void *)de) +
(EXT4_BLOCK_SIZE(inode->i_sb) -
sizeof(struct ext4_dir_entry_tail)));
while (d < top && d->rec_len)
d = (struct ext4_dir_entry *)(((void *)d) +
le16_to_cpu(d->rec_len));
if (d != top)
return NULL;
t = (struct ext4_dir_entry_tail *)d;
#else
t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
#endif
if (t->det_reserved_zero1 ||
le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
t->det_reserved_zero2 ||
t->det_reserved_ft != EXT4_FT_DIR_CSUM)
return NULL;
return t;
}
static __le32 ext4_dirent_csum(struct inode *inode,
struct ext4_dir_entry *dirent, int size)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
__u32 csum;
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
return cpu_to_le32(csum);
}
#define warn_no_space_for_csum(inode) \
__warn_no_space_for_csum((inode), __func__, __LINE__)
static void __warn_no_space_for_csum(struct inode *inode, const char *func,
unsigned int line)
{
__ext4_warning_inode(inode, func, line,
"No space for directory leaf checksum. Please run e2fsck -D.");
}
int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
{
struct ext4_dir_entry_tail *t;
if (!ext4_has_metadata_csum(inode->i_sb))
return 1;
t = get_dirent_tail(inode, dirent);
if (!t) {
warn_no_space_for_csum(inode);
return 0;
}
if (t->det_checksum != ext4_dirent_csum(inode, dirent,
(void *)t - (void *)dirent))
return 0;
return 1;
}
static void ext4_dirent_csum_set(struct inode *inode,
struct ext4_dir_entry *dirent)
{
struct ext4_dir_entry_tail *t;
if (!ext4_has_metadata_csum(inode->i_sb))
return;
t = get_dirent_tail(inode, dirent);
if (!t) {
warn_no_space_for_csum(inode);
return;
}
t->det_checksum = ext4_dirent_csum(inode, dirent,
(void *)t - (void *)dirent);
}
int ext4_handle_dirty_dirent_node(handle_t *handle,
struct inode *inode,
struct buffer_head *bh)
{
ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
return ext4_handle_dirty_metadata(handle, inode, bh);
}
static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
struct ext4_dir_entry *dirent,
int *offset)
{
struct ext4_dir_entry *dp;
struct dx_root_info *root;
int count_offset;
if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
count_offset = 8;
else if (le16_to_cpu(dirent->rec_len) == 12) {
dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
if (le16_to_cpu(dp->rec_len) !=
EXT4_BLOCK_SIZE(inode->i_sb) - 12)
return NULL;
root = (struct dx_root_info *)(((void *)dp + 12));
if (root->reserved_zero ||
root->info_length != sizeof(struct dx_root_info))
return NULL;
count_offset = 32;
} else
return NULL;
if (offset)
*offset = count_offset;
return (struct dx_countlimit *)(((void *)dirent) + count_offset);
}
static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
int count_offset, int count, struct dx_tail *t)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
__u32 csum;
int size;
__u32 dummy_csum = 0;
int offset = offsetof(struct dx_tail, dt_checksum);
size = count_offset + (count * sizeof(struct dx_entry));
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
return cpu_to_le32(csum);
}
static int ext4_dx_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent)
{
struct dx_countlimit *c;
struct dx_tail *t;
int count_offset, limit, count;
if (!ext4_has_metadata_csum(inode->i_sb))
return 1;
c = get_dx_countlimit(inode, dirent, &count_offset);
if (!c) {
EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
return 0;
}
limit = le16_to_cpu(c->limit);
count = le16_to_cpu(c->count);
if (count_offset + (limit * sizeof(struct dx_entry)) >
EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
warn_no_space_for_csum(inode);
return 0;
}
t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
count, t))
return 0;
return 1;
}
static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
{
struct dx_countlimit *c;
struct dx_tail *t;
int count_offset, limit, count;
if (!ext4_has_metadata_csum(inode->i_sb))
return;
c = get_dx_countlimit(inode, dirent, &count_offset);
if (!c) {
EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
return;
}
limit = le16_to_cpu(c->limit);
count = le16_to_cpu(c->count);
if (count_offset + (limit * sizeof(struct dx_entry)) >
EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
warn_no_space_for_csum(inode);
return;
}
t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
}
static inline int ext4_handle_dirty_dx_node(handle_t *handle,
struct inode *inode,
struct buffer_head *bh)
{
ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
return ext4_handle_dirty_metadata(handle, inode, bh);
}
/*
* p is at least 6 bytes before the end of page
*/
static inline struct ext4_dir_entry_2 *
ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
{
return (struct ext4_dir_entry_2 *)((char *)p +
ext4_rec_len_from_disk(p->rec_len, blocksize));
}
/*
* Future: use high four bits of block for coalesce-on-delete flags
* Mask them off for now.
*/
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
{
return le32_to_cpu(entry->block) & 0x0fffffff;
}
static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
{
entry->block = cpu_to_le32(value);
}
static inline unsigned dx_get_hash(struct dx_entry *entry)
{
return le32_to_cpu(entry->hash);
}
static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
{
entry->hash = cpu_to_le32(value);
}
static inline unsigned dx_get_count(struct dx_entry *entries)
{
return le16_to_cpu(((struct dx_countlimit *) entries)->count);
}
static inline unsigned dx_get_limit(struct dx_entry *entries)
{
return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
}
static inline void dx_set_count(struct dx_entry *entries, unsigned value)
{
((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
}
static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
{
((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
}
static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
EXT4_DIR_REC_LEN(2) - infosize;
if (ext4_has_metadata_csum(dir->i_sb))
entry_space -= sizeof(struct dx_tail);
return entry_space / sizeof(struct dx_entry);
}
static inline unsigned dx_node_limit(struct inode *dir)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
if (ext4_has_metadata_csum(dir->i_sb))
entry_space -= sizeof(struct dx_tail);
return entry_space / sizeof(struct dx_entry);
}
/*
* Debug
*/
#ifdef DX_DEBUG
static void dx_show_index(char * label, struct dx_entry *entries)
{
int i, n = dx_get_count (entries);
printk(KERN_DEBUG "%s index", label);
for (i = 0; i < n; i++) {
printk(KERN_CONT " %x->%lu",
i ? dx_get_hash(entries + i) : 0,
(unsigned long)dx_get_block(entries + i));
}
printk(KERN_CONT "\n");
}
struct stats
{
unsigned names;
unsigned space;
unsigned bcount;
};
static struct stats dx_show_leaf(struct inode *dir,
struct dx_hash_info *hinfo,
struct ext4_dir_entry_2 *de,
int size, int show_names)
{
unsigned names = 0, space = 0;
char *base = (char *) de;
struct dx_hash_info h = *hinfo;
printk("names: ");
while ((char *) de < base + size)
{
if (de->inode)
{
if (show_names)
{
#ifdef CONFIG_EXT4_FS_ENCRYPTION
int len;
char *name;
struct fscrypt_str fname_crypto_str =
FSTR_INIT(NULL, 0);
int res = 0;
name = de->name;
len = de->name_len;
if (ext4_encrypted_inode(dir))
res = fscrypt_get_encryption_info(dir);
if (res) {
printk(KERN_WARNING "Error setting up"
" fname crypto: %d\n", res);
}
if (!fscrypt_has_encryption_key(dir)) {
/* Directory is not encrypted */
ext4fs_dirhash(de->name,
de->name_len, &h);
printk("%*.s:(U)%x.%u ", len,
name, h.hash,
(unsigned) ((char *) de
- base));
} else {
struct fscrypt_str de_name =
FSTR_INIT(name, len);
/* Directory is encrypted */
res = fscrypt_fname_alloc_buffer(
dir, len,
&fname_crypto_str);
if (res)
printk(KERN_WARNING "Error "
"allocating crypto "
"buffer--skipping "
"crypto\n");
res = fscrypt_fname_disk_to_usr(dir,
0, 0, &de_name,
&fname_crypto_str);
if (res) {
printk(KERN_WARNING "Error "
"converting filename "
"from disk to usr"
"\n");
name = "??";
len = 2;
} else {
name = fname_crypto_str.name;
len = fname_crypto_str.len;
}
ext4fs_dirhash(de->name, de->name_len,
&h);
printk("%*.s:(E)%x.%u ", len, name,
h.hash, (unsigned) ((char *) de
- base));
fscrypt_fname_free_buffer(
&fname_crypto_str);
}
#else
int len = de->name_len;
char *name = de->name;
ext4fs_dirhash(de->name, de->name_len, &h);
printk("%*.s:%x.%u ", len, name, h.hash,
(unsigned) ((char *) de - base));
#endif
}
space += EXT4_DIR_REC_LEN(de->name_len);
names++;
}
de = ext4_next_entry(de, size);
}
printk(KERN_CONT "(%i)\n", names);
return (struct stats) { names, space, 1 };
}
struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
struct dx_entry *entries, int levels)
{
unsigned blocksize = dir->i_sb->s_blocksize;
unsigned count = dx_get_count(entries), names = 0, space = 0, i;
unsigned bcount = 0;
struct buffer_head *bh;
printk("%i indexed blocks...\n", count);
for (i = 0; i < count; i++, entries++)
{
ext4_lblk_t block = dx_get_block(entries);
ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
struct stats stats;
printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
bh = ext4_bread(NULL,dir, block, 0);
if (!bh || IS_ERR(bh))
continue;
stats = levels?
dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
bh->b_data, blocksize, 0);
names += stats.names;
space += stats.space;
bcount += stats.bcount;
brelse(bh);
}
if (bcount)
printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
levels ? "" : " ", names, space/bcount,
(space/bcount)*100/blocksize);
return (struct stats) { names, space, bcount};
}
#endif /* DX_DEBUG */
/*
* Probe for a directory leaf block to search.
*
* dx_probe can return ERR_BAD_DX_DIR, which means there was a format
* error in the directory index, and the caller should fall back to
* searching the directory normally. The callers of dx_probe **MUST**
* check for this error code, and make sure it never gets reflected
* back to userspace.
*/
static struct dx_frame *
dx_probe(struct ext4_filename *fname, struct inode *dir,
struct dx_hash_info *hinfo, struct dx_frame *frame_in)
{
unsigned count, indirect;
struct dx_entry *at, *entries, *p, *q, *m;
struct dx_root *root;
struct dx_frame *frame = frame_in;
struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
u32 hash;
memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
frame->bh = ext4_read_dirblock(dir, 0, INDEX);
if (IS_ERR(frame->bh))
return (struct dx_frame *) frame->bh;
root = (struct dx_root *) frame->bh->b_data;
if (root->info.hash_version != DX_HASH_TEA &&
root->info.hash_version != DX_HASH_HALF_MD4 &&
root->info.hash_version != DX_HASH_LEGACY) {
ext4_warning_inode(dir, "Unrecognised inode hash code %u",
root->info.hash_version);
goto fail;
}
if (fname)
hinfo = &fname->hinfo;
hinfo->hash_version = root->info.hash_version;
if (hinfo->hash_version <= DX_HASH_TEA)
hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
if (fname && fname_name(fname))
ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
hash = hinfo->hash;
if (root->info.unused_flags & 1) {
ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
root->info.unused_flags);
goto fail;
}
indirect = root->info.indirect_levels;
if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
ext4_warning(dir->i_sb,
"Directory (ino: %lu) htree depth %#06x exceed"
"supported value", dir->i_ino,
ext4_dir_htree_level(dir->i_sb));
if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
ext4_warning(dir->i_sb, "Enable large directory "
"feature to access it");
}
goto fail;
}
entries = (struct dx_entry *)(((char *)&root->info) +
root->info.info_length);
if (dx_get_limit(entries) != dx_root_limit(dir,
root->info.info_length)) {
ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
dx_get_limit(entries),
dx_root_limit(dir, root->info.info_length));
goto fail;
}
dxtrace(printk("Look up %x", hash));
while (1) {
count = dx_get_count(entries);
if (!count || count > dx_get_limit(entries)) {
ext4_warning_inode(dir,
"dx entry: count %u beyond limit %u",
count, dx_get_limit(entries));
goto fail;
}
p = entries + 1;
q = entries + count - 1;
while (p <= q) {
m = p + (q - p) / 2;
dxtrace(printk(KERN_CONT "."));
if (dx_get_hash(m) > hash)
q = m - 1;
else
p = m + 1;
}
if (0) { // linear search cross check
unsigned n = count - 1;
at = entries;
while (n--)
{
dxtrace(printk(KERN_CONT ","));
if (dx_get_hash(++at) > hash)
{
at--;
break;
}
}
assert (at == p - 1);
}
at = p - 1;
dxtrace(printk(KERN_CONT " %x->%u\n",
at == entries ? 0 : dx_get_hash(at),
dx_get_block(at)));
frame->entries = entries;
frame->at = at;
if (!indirect--)
return frame;
frame++;
frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
if (IS_ERR(frame->bh)) {
ret_err = (struct dx_frame *) frame->bh;
frame->bh = NULL;
goto fail;
}
entries = ((struct dx_node *) frame->bh->b_data)->entries;
if (dx_get_limit(entries) != dx_node_limit(dir)) {
ext4_warning_inode(dir,
"dx entry: limit %u != node limit %u",
dx_get_limit(entries), dx_node_limit(dir));
goto fail;
}
}
fail:
while (frame >= frame_in) {
brelse(frame->bh);
frame--;
}
if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
ext4_warning_inode(dir,
"Corrupt directory, running e2fsck is recommended");
return ret_err;
}
static void dx_release(struct dx_frame *frames)
{
struct dx_root_info *info;
int i;
if (frames[0].bh == NULL)
return;
info = &((struct dx_root *)frames[0].bh->b_data)->info;
for (i = 0; i <= info->indirect_levels; i++) {
if (frames[i].bh == NULL)
break;
brelse(frames[i].bh);
frames[i].bh = NULL;
}
}
/*
* This function increments the frame pointer to search the next leaf
* block, and reads in the necessary intervening nodes if the search
* should be necessary. Whether or not the search is necessary is
* controlled by the hash parameter. If the hash value is even, then
* the search is only continued if the next block starts with that
* hash value. This is used if we are searching for a specific file.
*
* If the hash value is HASH_NB_ALWAYS, then always go to the next block.
*
* This function returns 1 if the caller should continue to search,
* or 0 if it should not. If there is an error reading one of the
* index blocks, it will a negative error code.
*
* If start_hash is non-null, it will be filled in with the starting
* hash of the next page.
*/
static int ext4_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frame,
struct dx_frame *frames,
__u32 *start_hash)
{
struct dx_frame *p;
struct buffer_head *bh;
int num_frames = 0;
__u32 bhash;
p = frame;
/*
* Find the next leaf page by incrementing the frame pointer.
* If we run out of entries in the interior node, loop around and
* increment pointer in the parent node. When we break out of
* this loop, num_frames indicates the number of interior
* nodes need to be read.
*/
while (1) {
if (++(p->at) < p->entries + dx_get_count(p->entries))
break;
if (p == frames)
return 0;
num_frames++;
p--;
}
/*
* If the hash is 1, then continue only if the next page has a
* continuation hash of any value. This is used for readdir
* handling. Otherwise, check to see if the hash matches the
* desired contiuation hash. If it doesn't, return since
* there's no point to read in the successive index pages.
*/
bhash = dx_get_hash(p->at);
if (start_hash)
*start_hash = bhash;
if ((hash & 1) == 0) {
if ((bhash & ~1) != hash)
return 0;
}
/*
* If the hash is HASH_NB_ALWAYS, we always go to the next
* block so no check is necessary
*/
while (num_frames--) {
bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
if (IS_ERR(bh))
return PTR_ERR(bh);
p++;
brelse(p->bh);
p->bh = bh;
p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
}
return 1;
}
/*
* This function fills a red-black tree with information from a
* directory block. It returns the number directory entries loaded
* into the tree. If there is an error it is returned in err.
*/
static int htree_dirblock_to_tree(struct file *dir_file,
struct inode *dir, ext4_lblk_t block,
struct dx_hash_info *hinfo,
__u32 start_hash, __u32 start_minor_hash)
{
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *top;
int err = 0, count = 0;
struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
(unsigned long)block));
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh))
return PTR_ERR(bh);
de = (struct ext4_dir_entry_2 *) bh->b_data;
top = (struct ext4_dir_entry_2 *) ((char *) de +
dir->i_sb->s_blocksize -
EXT4_DIR_REC_LEN(0));
#ifdef CONFIG_EXT4_FS_ENCRYPTION
/* Check if the directory is encrypted */
if (ext4_encrypted_inode(dir)) {
err = fscrypt_get_encryption_info(dir);
if (err < 0) {
brelse(bh);
return err;
}
err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
&fname_crypto_str);
if (err < 0) {
brelse(bh);
return err;
}
}
#endif
for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
bh->b_data, bh->b_size,
(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
+ ((char *)de - bh->b_data))) {
/* silently ignore the rest of the block */
break;
}
ext4fs_dirhash(de->name, de->name_len, hinfo);
if ((hinfo->hash < start_hash) ||
((hinfo->hash == start_hash) &&
(hinfo->minor_hash < start_minor_hash)))
continue;
if (de->inode == 0)
continue;
if (!ext4_encrypted_inode(dir)) {
tmp_str.name = de->name;
tmp_str.len = de->name_len;
err = ext4_htree_store_dirent(dir_file,
hinfo->hash, hinfo->minor_hash, de,
&tmp_str);
} else {
int save_len = fname_crypto_str.len;
struct fscrypt_str de_name = FSTR_INIT(de->name,
de->name_len);
/* Directory is encrypted */
err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
hinfo->minor_hash, &de_name,
&fname_crypto_str);
if (err) {
count = err;
goto errout;
}
err = ext4_htree_store_dirent(dir_file,
hinfo->hash, hinfo->minor_hash, de,
&fname_crypto_str);
fname_crypto_str.len = save_len;
}
if (err != 0) {
count = err;
goto errout;
}
count++;
}
errout:
brelse(bh);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
fscrypt_fname_free_buffer(&fname_crypto_str);
#endif
return count;
}
/*
* This function fills a red-black tree with information from a
* directory. We start scanning the directory in hash order, starting
* at start_hash and start_minor_hash.
*
* This function returns the number of entries inserted into the tree,
* or a negative error code.
*/
int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
__u32 start_minor_hash, __u32 *next_hash)
{
struct dx_hash_info hinfo;
struct ext4_dir_entry_2 *de;
struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
struct inode *dir;
ext4_lblk_t block;
int count = 0;
int ret, err;
__u32 hashval;
struct fscrypt_str tmp_str;
dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
start_hash, start_minor_hash));
dir = file_inode(dir_file);
if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
if (hinfo.hash_version <= DX_HASH_TEA)
hinfo.hash_version +=
EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
count = htree_inlinedir_to_tree(dir_file, dir, 0,
&hinfo, start_hash,
start_minor_hash,
&has_inline_data);
if (has_inline_data) {
*next_hash = ~0;
return count;
}
}
count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
start_hash, start_minor_hash);
*next_hash = ~0;
return count;
}
hinfo.hash = start_hash;
hinfo.minor_hash = 0;
frame = dx_probe(NULL, dir, &hinfo, frames);
if (IS_ERR(frame))
return PTR_ERR(frame);
/* Add '.' and '..' from the htree header */
if (!start_hash && !start_minor_hash) {
de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
tmp_str.name = de->name;
tmp_str.len = de->name_len;
err = ext4_htree_store_dirent(dir_file, 0, 0,
de, &tmp_str);
if (err != 0)
goto errout;
count++;
}
if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
de = ext4_next_entry(de, dir->i_sb->s_blocksize);
tmp_str.name = de->name;
tmp_str.len = de->name_len;
err = ext4_htree_store_dirent(dir_file, 2, 0,
de, &tmp_str);
if (err != 0)
goto errout;
count++;
}
while (1) {
if (fatal_signal_pending(current)) {
err = -ERESTARTSYS;
goto errout;
}
cond_resched();
block = dx_get_block(frame->at);
ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
start_hash, start_minor_hash);
if (ret < 0) {
err = ret;
goto errout;
}
count += ret;
hashval = ~0;
ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
frame, frames, &hashval);
*next_hash = hashval;
if (ret < 0) {
err = ret;
goto errout;
}
/*
* Stop if: (a) there are no more entries, or
* (b) we have inserted at least one entry and the
* next hash value is not a continuation
*/
if ((ret == 0) ||
(count && ((hashval & 1) == 0)))
break;
}
dx_release(frames);
dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
"next hash: %x\n", count, *next_hash));
return count;
errout:
dx_release(frames);
return (err);
}
static inline int search_dirblock(struct buffer_head *bh,
struct inode *dir,
struct ext4_filename *fname,
unsigned int offset,
struct ext4_dir_entry_2 **res_dir)
{
return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
fname, offset, res_dir);
}
/*
* Directory block splitting, compacting
*/
/*
* Create map of hash values, offsets, and sizes, stored at end of block.
* Returns number of entries mapped.
*/
static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
unsigned blocksize, struct dx_hash_info *hinfo,
struct dx_map_entry *map_tail)
{
int count = 0;
char *base = (char *) de;
struct dx_hash_info h = *hinfo;
while ((char *) de < base + blocksize) {
if (de->name_len && de->inode) {
ext4fs_dirhash(de->name, de->name_len, &h);
map_tail--;
map_tail->hash = h.hash;
map_tail->offs = ((char *) de - base)>>2;
map_tail->size = le16_to_cpu(de->rec_len);
count++;
cond_resched();
}
/* XXX: do we need to check rec_len == 0 case? -Chris */
de = ext4_next_entry(de, blocksize);
}
return count;
}
/* Sort map by hash value */
static void dx_sort_map (struct dx_map_entry *map, unsigned count)
{
struct dx_map_entry *p, *q, *top = map + count - 1;
int more;
/* Combsort until bubble sort doesn't suck */
while (count > 2) {
count = count*10/13;
if (count - 9 < 2) /* 9, 10 -> 11 */
count = 11;
for (p = top, q = p - count; q >= map; p--, q--)
if (p->hash < q->hash)
swap(*p, *q);
}
/* Garden variety bubble sort */
do {
more = 0;
q = top;
while (q-- > map) {
if (q[1].hash >= q[0].hash)
continue;
swap(*(q+1), *q);
more = 1;
}
} while(more);
}
static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
{
struct dx_entry *entries = frame->entries;
struct dx_entry *old = frame->at, *new = old + 1;
int count = dx_get_count(entries);
assert(count < dx_get_limit(entries));
assert(old < entries + count);
memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
dx_set_hash(new, hash);
dx_set_block(new, block);
dx_set_count(entries, count + 1);
}
/*
* Test whether a directory entry matches the filename being searched for.
*
* Return: %true if the directory entry matches, otherwise %false.
*/
static inline bool ext4_match(const struct ext4_filename *fname,
const struct ext4_dir_entry_2 *de)
{
struct fscrypt_name f;
if (!de->inode)
return false;
f.usr_fname = fname->usr_fname;
f.disk_name = fname->disk_name;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
f.crypto_buf = fname->crypto_buf;
#endif
return fscrypt_match_name(&f, de->name, de->name_len);
}
/*
* Returns 0 if not found, -1 on failure, and 1 on success
*/
int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
struct inode *dir, struct ext4_filename *fname,
unsigned int offset, struct ext4_dir_entry_2 **res_dir)
{
struct ext4_dir_entry_2 * de;
char * dlimit;
int de_len;
de = (struct ext4_dir_entry_2 *)search_buf;
dlimit = search_buf + buf_size;
while ((char *) de < dlimit) {
/* this code is executed quadratically often */
/* do minimal checking `by hand' */
if ((char *) de + de->name_len <= dlimit &&
ext4_match(fname, de)) {
/* found a match - just to be sure, do
* a full check */
if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
bh->b_size, offset))
return -1;
*res_dir = de;
return 1;
}
/* prevent looping on a bad block */
de_len = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
if (de_len <= 0)
return -1;
offset += de_len;
de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
}
return 0;
}
static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
struct ext4_dir_entry *de)
{
struct super_block *sb = dir->i_sb;
if (!is_dx(dir))
return 0;
if (block == 0)
return 1;
if (de->inode == 0 &&
ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
sb->s_blocksize)
return 1;
return 0;
}
/*
* ext4_find_entry()
*
* finds an entry in the specified directory with the wanted name. It
* returns the cache buffer in which the entry was found, and the entry
* itself (as a parameter - res_dir). It does NOT read the inode of the
* entry - you'll have to do that yourself if you want to.
*
* The returned buffer_head has ->b_count elevated. The caller is expected
* to brelse() it when appropriate.
*/
static struct buffer_head * ext4_find_entry (struct inode *dir,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *inlined)
{
struct super_block *sb;
struct buffer_head *bh_use[NAMEI_RA_SIZE];
struct buffer_head *bh, *ret = NULL;
ext4_lblk_t start, block;
const u8 *name = d_name->name;
size_t ra_max = 0; /* Number of bh's in the readahead
buffer, bh_use[] */
size_t ra_ptr = 0; /* Current index into readahead
buffer */
ext4_lblk_t nblocks;
int i, namelen, retval;
struct ext4_filename fname;
*res_dir = NULL;
sb = dir->i_sb;
namelen = d_name->len;
if (namelen > EXT4_NAME_LEN)
return NULL;
retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
if (retval == -ENOENT)
return NULL;
if (retval)
return ERR_PTR(retval);
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
ret = ext4_find_inline_entry(dir, &fname, res_dir,
&has_inline_data);
if (has_inline_data) {
if (inlined)
*inlined = 1;
goto cleanup_and_exit;
}
}
if ((namelen <= 2) && (name[0] == '.') &&
(name[1] == '.' || name[1] == '\0')) {
/*
* "." or ".." will only be in the first block
* NFS may look up ".."; "." should be handled by the VFS
*/
block = start = 0;
nblocks = 1;
goto restart;
}
if (is_dx(dir)) {
ret = ext4_dx_find_entry(dir, &fname, res_dir);
/*
* On success, or if the error was file not found,
* return. Otherwise, fall back to doing a search the
* old fashioned way.
*/
if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
goto cleanup_and_exit;
dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
"falling back\n"));
}
nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
if (!nblocks) {
ret = NULL;
goto cleanup_and_exit;
}
start = EXT4_I(dir)->i_dir_start_lookup;
if (start >= nblocks)
start = 0;
block = start;
restart:
do {
/*
* We deal with the read-ahead logic here.
*/
if (ra_ptr >= ra_max) {
/* Refill the readahead buffer */
ra_ptr = 0;
if (block < start)
ra_max = start - block;
else
ra_max = nblocks - block;
ra_max = min(ra_max, ARRAY_SIZE(bh_use));
retval = ext4_bread_batch(dir, block, ra_max,
false /* wait */, bh_use);
if (retval) {
ret = ERR_PTR(retval);
ra_max = 0;
goto cleanup_and_exit;
}
}
if ((bh = bh_use[ra_ptr++]) == NULL)
goto next;
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
(unsigned long) block);
brelse(bh);
ret = ERR_PTR(-EIO);
goto cleanup_and_exit;
}
if (!buffer_verified(bh) &&
!is_dx_internal_node(dir, block,
(struct ext4_dir_entry *)bh->b_data) &&
!ext4_dirent_csum_verify(dir,
(struct ext4_dir_entry *)bh->b_data)) {
EXT4_ERROR_INODE(dir, "checksumming directory "
"block %lu", (unsigned long)block);
brelse(bh);
ret = ERR_PTR(-EFSBADCRC);
goto cleanup_and_exit;
}
set_buffer_verified(bh);
i = search_dirblock(bh, dir, &fname,
block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
if (i == 1) {
EXT4_I(dir)->i_dir_start_lookup = block;
ret = bh;
goto cleanup_and_exit;
} else {
brelse(bh);
if (i < 0)
goto cleanup_and_exit;
}
next:
if (++block >= nblocks)
block = 0;
} while (block != start);
/*
* If the directory has grown while we were searching, then
* search the last part of the directory before giving up.
*/
block = nblocks;
nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
if (block < nblocks) {
start = 0;
goto restart;
}
cleanup_and_exit:
/* Clean up the read-ahead blocks */
for (; ra_ptr < ra_max; ra_ptr++)
brelse(bh_use[ra_ptr]);
ext4_fname_free_filename(&fname);
return ret;
}
static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
struct ext4_filename *fname,
struct ext4_dir_entry_2 **res_dir)
{
struct super_block * sb = dir->i_sb;
struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
struct buffer_head *bh;
ext4_lblk_t block;
int retval;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
*res_dir = NULL;
#endif
frame = dx_probe(fname, dir, NULL, frames);
if (IS_ERR(frame))
return (struct buffer_head *) frame;
do {
block = dx_get_block(frame->at);
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh))
goto errout;
retval = search_dirblock(bh, dir, fname,
block << EXT4_BLOCK_SIZE_BITS(sb),
res_dir);
if (retval == 1)
goto success;
brelse(bh);
if (retval == -1) {
bh = ERR_PTR(ERR_BAD_DX_DIR);
goto errout;
}
/* Check to see if we should continue to search */
retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
frames, NULL);
if (retval < 0) {
ext4_warning_inode(dir,
"error %d reading directory index block",
retval);
bh = ERR_PTR(retval);
goto errout;
}
} while (retval == 1);
bh = NULL;
errout:
dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
success:
dx_release(frames);
return bh;
}
static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct ext4_dir_entry_2 *de;
struct buffer_head *bh;
int err;
err = fscrypt_prepare_lookup(dir, dentry, flags);
if (err)
return ERR_PTR(err);
if (dentry->d_name.len > EXT4_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (IS_ERR(bh))
return (struct dentry *) bh;
inode = NULL;
if (bh) {
__u32 ino = le32_to_cpu(de->inode);
brelse(bh);
if (!ext4_valid_inum(dir->i_sb, ino)) {
EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
return ERR_PTR(-EFSCORRUPTED);
}
if (unlikely(ino == dir->i_ino)) {
EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
dentry);
return ERR_PTR(-EFSCORRUPTED);
}
inode = ext4_iget_normal(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
EXT4_ERROR_INODE(dir,
"deleted inode referenced: %u",
ino);
return ERR_PTR(-EFSCORRUPTED);
}
if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
!fscrypt_has_permitted_context(dir, inode)) {
ext4_warning(inode->i_sb,
"Inconsistent encryption contexts: %lu/%lu",
dir->i_ino, inode->i_ino);
iput(inode);
return ERR_PTR(-EPERM);
}
}
return d_splice_alias(inode, dentry);
}
struct dentry *ext4_get_parent(struct dentry *child)
{
__u32 ino;
static const struct qstr dotdot = QSTR_INIT("..", 2);
struct ext4_dir_entry_2 * de;
struct buffer_head *bh;
bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
if (IS_ERR(bh))
return (struct dentry *) bh;
if (!bh)
return ERR_PTR(-ENOENT);
ino = le32_to_cpu(de->inode);
brelse(bh);
if (!ext4_valid_inum(child->d_sb, ino)) {
EXT4_ERROR_INODE(d_inode(child),
"bad parent inode number: %u", ino);
return ERR_PTR(-EFSCORRUPTED);
}
return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));
}
/*
* Move count entries from end of map between two memory locations.
* Returns pointer to last entry moved.
*/
static struct ext4_dir_entry_2 *
dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
unsigned blocksize)
{
unsigned rec_len = 0;
while (count--) {
struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
(from + (map->offs<<2));
rec_len = EXT4_DIR_REC_LEN(de->name_len);
memcpy (to, de, rec_len);
((struct ext4_dir_entry_2 *) to)->rec_len =
ext4_rec_len_to_disk(rec_len, blocksize);
de->inode = 0;
map++;
to += rec_len;
}
return (struct ext4_dir_entry_2 *) (to - rec_len);
}
/*
* Compact each dir entry in the range to the minimal rec_len.
* Returns pointer to last entry in range.
*/
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
{
struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
unsigned rec_len = 0;
prev = to = de;
while ((char*)de < base + blocksize) {
next = ext4_next_entry(de, blocksize);
if (de->inode && de->name_len) {
rec_len = EXT4_DIR_REC_LEN(de->name_len);
if (de > to)
memmove(to, de, rec_len);
to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
prev = to;
to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
}
de = next;
}
return prev;
}
/*
* Split a full leaf block to make room for a new dir entry.
* Allocate a new block, and move entries so that they are approx. equally full.
* Returns pointer to de in block into which the new entry will be inserted.
*/
static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
struct buffer_head **bh,struct dx_frame *frame,
struct dx_hash_info *hinfo)
{
unsigned blocksize = dir->i_sb->s_blocksize;
unsigned count, continued;
struct buffer_head *bh2;
ext4_lblk_t newblock;
u32 hash2;
struct dx_map_entry *map;
char *data1 = (*bh)->b_data, *data2;
unsigned split, move, size;
struct ext4_dir_entry_2 *de = NULL, *de2;
struct ext4_dir_entry_tail *t;
int csum_size = 0;
int err = 0, i;
if (ext4_has_metadata_csum(dir->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
bh2 = ext4_append(handle, dir, &newblock);
if (IS_ERR(bh2)) {
brelse(*bh);
*bh = NULL;
return (struct ext4_dir_entry_2 *) bh2;
}
BUFFER_TRACE(*bh, "get_write_access");
err = ext4_journal_get_write_access(handle, *bh);
if (err)
goto journal_error;
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext4_journal_get_write_access(handle, frame->bh);
if (err)
goto journal_error;
data2 = bh2->b_data;
/* create map in the end of data2 block */
map = (struct dx_map_entry *) (data2 + blocksize);
count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
blocksize, hinfo, map);
map -= count;
dx_sort_map(map, count);
/* Split the existing block in the middle, size-wise */
size = 0;
move = 0;
for (i = count-1; i >= 0; i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
size += map[i].size;
move++;
}
/* map index at which we will split */
split = count - move;
hash2 = map[split].hash;
continued = hash2 == map[split - 1].hash;
dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
(unsigned long)dx_get_block(frame->at),
hash2, split, count-split));
/* Fancy dance to stay within two buffers */
de2 = dx_move_dirents(data1, data2, map + split, count - split,
blocksize);
de = dx_pack_dirents(data1, blocksize);
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
blocksize);
de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
(char *) de2,
blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(data2, blocksize);
initialize_dirent_tail(t, blocksize);
t = EXT4_DIRENT_TAIL(data1, blocksize);
initialize_dirent_tail(t, blocksize);
}
dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
blocksize, 1));
dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
blocksize, 1));
/* Which block gets the new entry? */
if (hinfo->hash >= hash2) {
swap(*bh, bh2);
de = de2;
}
dx_insert_block(frame, hash2 + continued, newblock);
err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
if (err)
goto journal_error;
err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (err)
goto journal_error;
brelse(bh2);
dxtrace(dx_show_index("frame", frame->entries));
return de;
journal_error:
brelse(*bh);
brelse(bh2);
*bh = NULL;
ext4_std_error(dir->i_sb, err);
return ERR_PTR(err);
}
int ext4_find_dest_de(struct inode *dir, struct inode *inode,
struct buffer_head *bh,
void *buf, int buf_size,
struct ext4_filename *fname,
struct ext4_dir_entry_2 **dest_de)
{
struct ext4_dir_entry_2 *de;
unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
int nlen, rlen;
unsigned int offset = 0;
char *top;
de = (struct ext4_dir_entry_2 *)buf;
top = buf + buf_size - reclen;
while ((char *) de <= top) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
buf, buf_size, offset))
return -EFSCORRUPTED;
if (ext4_match(fname, de))
return -EEXIST;
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if ((de->inode ? rlen - nlen : rlen) >= reclen)
break;
de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
offset += rlen;
}
if ((char *) de > top)
return -ENOSPC;
*dest_de = de;
return 0;
}
void ext4_insert_dentry(struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
struct ext4_filename *fname)
{
int nlen, rlen;
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if (de->inode) {
struct ext4_dir_entry_2 *de1 =
(struct ext4_dir_entry_2 *)((char *)de + nlen);
de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
de = de1;
}
de->file_type = EXT4_FT_UNKNOWN;
de->inode = cpu_to_le32(inode->i_ino);
ext4_set_de_type(inode->i_sb, de, inode->i_mode);
de->name_len = fname_len(fname);
memcpy(de->name, fname_name(fname), fname_len(fname));
}
/*
* Add a new entry into a directory (leaf) block. If de is non-NULL,
* it points to a directory entry which is guaranteed to be large
* enough for new directory entry. If de is NULL, then
* add_dirent_to_buf will attempt search the directory block for
* space. It will return -ENOSPC if no space is available, and -EIO
* and -EEXIST if directory entry already exists.
*/
static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
struct inode *dir,
struct inode *inode, struct ext4_dir_entry_2 *de,
struct buffer_head *bh)
{
unsigned int blocksize = dir->i_sb->s_blocksize;
int csum_size = 0;
int err;
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
if (!de) {
err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
blocksize - csum_size, fname, &de);
if (err)
return err;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err) {
ext4_std_error(dir->i_sb, err);
return err;
}
/* By now the buffer is marked for journaling */
ext4_insert_dentry(inode, de, blocksize, fname);
/*
* XXX shouldn't update any times until successful
* completion of syscall, but too many callers depend
* on this.
*
* XXX similarly, too many callers depend on
* ext4_new_inode() setting the times, but error
* recovery deletes the inode, so the worst that can
* happen is that the times are slightly out of date
* and/or different from the directory change time.
*/
dir->i_mtime = dir->i_ctime = current_time(dir);
ext4_update_dx_flag(dir);
inode_inc_iversion(dir);
ext4_mark_inode_dirty(handle, dir);
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, dir, bh);
if (err)
ext4_std_error(dir->i_sb, err);
return 0;
}
/*
* This converts a one block unindexed directory to a 3 block indexed
* directory, and adds the dentry to the indexed directory.
*/
static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
struct inode *dir,
struct inode *inode, struct buffer_head *bh)
{
struct buffer_head *bh2;
struct dx_root *root;
struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
struct dx_entry *entries;
struct ext4_dir_entry_2 *de, *de2;
struct ext4_dir_entry_tail *t;
char *data1, *top;
unsigned len;
int retval;
unsigned blocksize;
ext4_lblk_t block;
struct fake_dirent *fde;
int csum_size = 0;
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
blocksize = dir->i_sb->s_blocksize;
dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
BUFFER_TRACE(bh, "get_write_access");
retval = ext4_journal_get_write_access(handle, bh);
if (retval) {
ext4_std_error(dir->i_sb, retval);
brelse(bh);
return retval;
}
root = (struct dx_root *) bh->b_data;
/* The 0th block becomes the root, move the dirents out */
fde = &root->dotdot;
de = (struct ext4_dir_entry_2 *)((char *)fde +
ext4_rec_len_from_disk(fde->rec_len, blocksize));
if ((char *) de >= (((char *) root) + blocksize)) {
EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
brelse(bh);
return -EFSCORRUPTED;
}
len = ((char *) root) + (blocksize - csum_size) - (char *) de;
/* Allocate new block for the 0th block's dirents */
bh2 = ext4_append(handle, dir, &block);
if (IS_ERR(bh2)) {
brelse(bh);
return PTR_ERR(bh2);
}
ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
data1 = bh2->b_data;
memcpy (data1, de, len);
de = (struct ext4_dir_entry_2 *) data1;
top = data1 + len;
while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
de = de2;
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(data1, blocksize);
initialize_dirent_tail(t, blocksize);
}
/* Initialize the root; the dot dirents already exist */
de = (struct ext4_dir_entry_2 *) (&root->dotdot);
de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
blocksize);
memset (&root->info, 0, sizeof(root->info));
root->info.info_length = sizeof(root->info);
root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
entries = root->entries;
dx_set_block(entries, 1);
dx_set_count(entries, 1);
dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
/* Initialize as for dx_probe */
fname->hinfo.hash_version = root->info.hash_version;
if (fname->hinfo.hash_version <= DX_HASH_TEA)
fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
memset(frames, 0, sizeof(frames));
frame = frames;
frame->entries = entries;
frame->at = entries;
frame->bh = bh;
retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (retval)
goto out_frames;
retval = ext4_handle_dirty_dirent_node(handle, dir, bh2);
if (retval)
goto out_frames;
de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
if (IS_ERR(de)) {
retval = PTR_ERR(de);
goto out_frames;
}
retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
out_frames:
/*
* Even if the block split failed, we have to properly write
* out all the changes we did so far. Otherwise we can end up
* with corrupted filesystem.
*/
if (retval)
ext4_mark_inode_dirty(handle, dir);
dx_release(frames);
brelse(bh2);
return retval;
}
/*
* ext4_add_entry()
*
* adds a file entry to the specified directory, using the same
* semantics as ext4_find_entry(). It returns NULL if it failed.
*
* NOTE!! The inode part of 'de' is left at 0 - which means you
* may not sleep between calling this and putting something into
* the entry, as someone else might have used it while you slept.
*/
static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
struct inode *inode)
{
struct inode *dir = d_inode(dentry->d_parent);
struct buffer_head *bh = NULL;
struct ext4_dir_entry_2 *de;
struct ext4_dir_entry_tail *t;
struct super_block *sb;
struct ext4_filename fname;
int retval;
int dx_fallback=0;
unsigned blocksize;
ext4_lblk_t block, blocks;
int csum_size = 0;
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
sb = dir->i_sb;
blocksize = sb->s_blocksize;
if (!dentry->d_name.len)
return -EINVAL;
retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
if (retval)
return retval;
if (ext4_has_inline_data(dir)) {
retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
if (retval < 0)
goto out;
if (retval == 1) {
retval = 0;
goto out;
}
}
if (is_dx(dir)) {
retval = ext4_dx_add_entry(handle, &fname, dir, inode);
if (!retval || (retval != ERR_BAD_DX_DIR))
goto out;
ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
dx_fallback++;
ext4_mark_inode_dirty(handle, dir);
}
blocks = dir->i_size >> sb->s_blocksize_bits;
for (block = 0; block < blocks; block++) {
bh = ext4_read_dirblock(dir, block, DIRENT);
if (IS_ERR(bh)) {
retval = PTR_ERR(bh);
bh = NULL;
goto out;
}
retval = add_dirent_to_buf(handle, &fname, dir, inode,
NULL, bh);
if (retval != -ENOSPC)
goto out;
if (blocks == 1 && !dx_fallback &&
ext4_has_feature_dir_index(sb)) {
retval = make_indexed_dir(handle, &fname, dir,
inode, bh);
bh = NULL; /* make_indexed_dir releases bh */
goto out;
}
brelse(bh);
}
bh = ext4_append(handle, dir, &block);
if (IS_ERR(bh)) {
retval = PTR_ERR(bh);
bh = NULL;
goto out;
}
de = (struct ext4_dir_entry_2 *) bh->b_data;
de->inode = 0;
de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
if (csum_size) {
t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
initialize_dirent_tail(t, blocksize);
}
retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
out:
ext4_fname_free_filename(&fname);
brelse(bh);
if (retval == 0)
ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
return retval;
}
/*
* Returns 0 for success, or a negative error value
*/
static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
struct inode *dir, struct inode *inode)
{
struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
struct dx_entry *entries, *at;
struct buffer_head *bh;
struct super_block *sb = dir->i_sb;
struct ext4_dir_entry_2 *de;
int restart;
int err;
again:
restart = 0;
frame = dx_probe(fname, dir, NULL, frames);
if (IS_ERR(frame))
return PTR_ERR(frame);
entries = frame->entries;
at = frame->at;
bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
bh = NULL;
goto cleanup;
}
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (err)
goto journal_error;
err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
if (err != -ENOSPC)
goto cleanup;
err = 0;
/* Block full, should compress but for now just split */
dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
dx_get_count(entries), dx_get_limit(entries)));
/* Need to split index? */
if (dx_get_count(entries) == dx_get_limit(entries)) {
ext4_lblk_t newblock;
int levels = frame - frames + 1;
unsigned int icount;
int add_level = 1;
struct dx_entry *entries2;
struct dx_node *node2;
struct buffer_head *bh2;
while (frame > frames) {
if (dx_get_count((frame - 1)->entries) <
dx_get_limit((frame - 1)->entries)) {
add_level = 0;
break;
}
frame--; /* split higher index block */
at = frame->at;
entries = frame->entries;
restart = 1;
}
if (add_level && levels == ext4_dir_htree_level(sb)) {
ext4_warning(sb, "Directory (ino: %lu) index full, "
"reach max htree level :%d",
dir->i_ino, levels);
if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
ext4_warning(sb, "Large directory feature is "
"not enabled on this "
"filesystem");
}
err = -ENOSPC;
goto cleanup;
}
icount = dx_get_count(entries);
bh2 = ext4_append(handle, dir, &newblock);
if (IS_ERR(bh2)) {
err = PTR_ERR(bh2);
goto cleanup;
}
node2 = (struct dx_node *)(bh2->b_data);
entries2 = node2->entries;
memset(&node2->fake, 0, sizeof(struct fake_dirent));
node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
sb->s_blocksize);
BUFFER_TRACE(frame->bh, "get_write_access");
err = ext4_journal_get_write_access(handle, frame->bh);
if (err)
goto journal_error;
if (!add_level) {
unsigned icount1 = icount/2, icount2 = icount - icount1;
unsigned hash2 = dx_get_hash(entries + icount1);
dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
icount1, icount2));
BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
err = ext4_journal_get_write_access(handle,
(frame - 1)->bh);
if (err)
goto journal_error;
memcpy((char *) entries2, (char *) (entries + icount1),
icount2 * sizeof(struct dx_entry));
dx_set_count(entries, icount1);
dx_set_count(entries2, icount2);
dx_set_limit(entries2, dx_node_limit(dir));
/* Which index block gets the new entry? */
if (at - entries >= icount1) {
frame->at = at = at - entries - icount1 + entries2;
frame->entries = entries = entries2;
swap(frame->bh, bh2);
}
dx_insert_block((frame - 1), hash2, newblock);
dxtrace(dx_show_index("node", frame->entries));
dxtrace(dx_show_index("node",
((struct dx_node *) bh2->b_data)->entries));
err = ext4_handle_dirty_dx_node(handle, dir, bh2);
if (err)
goto journal_error;
brelse (bh2);
err = ext4_handle_dirty_dx_node(handle, dir,
(frame - 1)->bh);
if (err)
goto journal_error;
if (restart) {
err = ext4_handle_dirty_dx_node(handle, dir,
frame->bh);
goto journal_error;
}
} else {
struct dx_root *dxroot;
memcpy((char *) entries2, (char *) entries,
icount * sizeof(struct dx_entry));
dx_set_limit(entries2, dx_node_limit(dir));
/* Set up root */
dx_set_count(entries, 1);
dx_set_block(entries + 0, newblock);
dxroot = (struct dx_root *)frames[0].bh->b_data;
dxroot->info.indirect_levels += 1;
dxtrace(printk(KERN_DEBUG
"Creating %d level index...\n",
info->indirect_levels));
err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (err)
goto journal_error;
err = ext4_handle_dirty_dx_node(handle, dir, bh2);
brelse(bh2);
restart = 1;
goto journal_error;
}
}
de = do_split(handle, dir, &bh, frame, &fname->hinfo);
if (IS_ERR(de)) {
err = PTR_ERR(de);
goto cleanup;
}
err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
goto cleanup;
journal_error:
ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
cleanup:
brelse(bh);
dx_release(frames);
/* @restart is true means htree-path has been changed, we need to
* repeat dx_probe() to find out valid htree-path
*/
if (restart && err == 0)
goto again;
return err;
}
/*
* ext4_generic_delete_entry deletes a directory entry by merging it
* with the previous entry
*/
int ext4_generic_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
struct buffer_head *bh,
void *entry_buf,
int buf_size,
int csum_size)
{
struct ext4_dir_entry_2 *de, *pde;
unsigned int blocksize = dir->i_sb->s_blocksize;
int i;
i = 0;
pde = NULL;
de = (struct ext4_dir_entry_2 *)entry_buf;
while (i < buf_size - csum_size) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
bh->b_data, bh->b_size, i))
return -EFSCORRUPTED;
if (de == de_del) {
if (pde)
pde->rec_len = ext4_rec_len_to_disk(
ext4_rec_len_from_disk(pde->rec_len,
blocksize) +
ext4_rec_len_from_disk(de->rec_len,
blocksize),
blocksize);
else
de->inode = 0;
inode_inc_iversion(dir);
return 0;
}
i += ext4_rec_len_from_disk(de->rec_len, blocksize);
pde = de;
de = ext4_next_entry(de, blocksize);
}
return -ENOENT;
}
static int ext4_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
struct buffer_head *bh)
{
int err, csum_size = 0;
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
err = ext4_delete_inline_entry(handle, dir, de_del, bh,
&has_inline_data);
if (has_inline_data)
return err;
}
if (ext4_has_metadata_csum(dir->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
BUFFER_TRACE(bh, "get_write_access");
err = ext4_journal_get_write_access(handle, bh);
if (unlikely(err))
goto out;
err = ext4_generic_delete_entry(handle, dir, de_del,
bh, bh->b_data,
dir->i_sb->s_blocksize, csum_size);
if (err)
goto out;
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, dir, bh);
if (unlikely(err))
goto out;
return 0;
out:
if (err != -ENOENT)
ext4_std_error(dir->i_sb, err);
return err;
}
/*
* Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
* since this indicates that nlinks count was previously 1 to avoid overflowing
* the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
* that subdirectory link counts are not being maintained accurately.
*
* The caller has already checked for i_nlink overflow in case the DIR_LINK
* feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
* for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
* on regular files) and to avoid creating huge/slow non-HTREE directories.
*/
static void ext4_inc_count(handle_t *handle, struct inode *inode)
{
inc_nlink(inode);
if (is_dx(inode) &&
(inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
set_nlink(inode, 1);
}
/*
* If a directory had nlink == 1, then we should let it be 1. This indicates
* directory has >EXT4_LINK_MAX subdirs.
*/
static void ext4_dec_count(handle_t *handle, struct inode *inode)
{
if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
drop_nlink(inode);
}
static int ext4_add_nondir(handle_t *handle,
struct dentry *dentry, struct inode *inode)
{
int err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
d_instantiate_new(dentry, inode);
return 0;
}
drop_nlink(inode);
unlock_new_inode(inode);
iput(inode);
return err;
}
/*
* By the time this is called, we already have created
* the directory cache entry for the new file, but it
* is so far negative - it has no inode.
*
* If the create succeeds, we fill in the inode information
* with d_instantiate().
*/
static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
err = dquot_initialize(dir);
if (err)
return err;
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext4_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
err = dquot_initialize(dir);
if (err)
return err;
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
inode->i_op = &ext4_special_inode_operations;
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
handle_t *handle;
struct inode *inode;
int err, retries = 0;
err = dquot_initialize(dir);
if (err)
return err;
retry:
inode = ext4_new_inode_start_handle(dir, mode,
NULL, 0, NULL,
EXT4_HT_DIR,
EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
4 + EXT4_XATTR_TRANS_BLOCKS);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
d_tmpfile(dentry, inode);
err = ext4_orphan_add(handle, inode);
if (err)
goto err_unlock_inode;
mark_inode_dirty(inode);
unlock_new_inode(inode);
}
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
err_unlock_inode:
ext4_journal_stop(handle);
unlock_new_inode(inode);
return err;
}
struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
struct ext4_dir_entry_2 *de,
int blocksize, int csum_size,
unsigned int parent_ino, int dotdot_real_len)
{
de->inode = cpu_to_le32(inode->i_ino);
de->name_len = 1;
de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
blocksize);
strcpy(de->name, ".");
ext4_set_de_type(inode->i_sb, de, S_IFDIR);
de = ext4_next_entry(de, blocksize);
de->inode = cpu_to_le32(parent_ino);
de->name_len = 2;
if (!dotdot_real_len)
de->rec_len = ext4_rec_len_to_disk(blocksize -
(csum_size + EXT4_DIR_REC_LEN(1)),
blocksize);
else
de->rec_len = ext4_rec_len_to_disk(
EXT4_DIR_REC_LEN(de->name_len), blocksize);
strcpy(de->name, "..");
ext4_set_de_type(inode->i_sb, de, S_IFDIR);
return ext4_next_entry(de, blocksize);
}
static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
struct inode *inode)
{
struct buffer_head *dir_block = NULL;
struct ext4_dir_entry_2 *de;
struct ext4_dir_entry_tail *t;
ext4_lblk_t block = 0;
unsigned int blocksize = dir->i_sb->s_blocksize;
int csum_size = 0;
int err;
if (ext4_has_metadata_csum(dir->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
err = ext4_try_create_inline_dir(handle, dir, inode);
if (err < 0 && err != -ENOSPC)
goto out;
if (!err)
goto out;
}
inode->i_size = 0;
dir_block = ext4_append(handle, inode, &block);
if (IS_ERR(dir_block))
return PTR_ERR(dir_block);
de = (struct ext4_dir_entry_2 *)dir_block->b_data;
ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
set_nlink(inode, 2);
if (csum_size) {
t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
initialize_dirent_tail(t, blocksize);
}
BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
if (err)
goto out;
set_buffer_verified(dir_block);
out:
brelse(dir_block);
return err;
}
static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
handle_t *handle;
struct inode *inode;
int err, credits, retries = 0;
if (EXT4_DIR_LINK_MAX(dir))
return -EMLINK;
err = dquot_initialize(dir);
if (err)
return err;
credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
&dentry->d_name,
0, NULL, EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_stop;
inode->i_op = &ext4_dir_inode_operations;
inode->i_fop = &ext4_dir_operations;
err = ext4_init_new_dir(handle, dir, inode);
if (err)
goto out_clear_inode;
err = ext4_mark_inode_dirty(handle, inode);
if (!err)
err = ext4_add_entry(handle, dentry, inode);
if (err) {
out_clear_inode:
clear_nlink(inode);
unlock_new_inode(inode);
ext4_mark_inode_dirty(handle, inode);
iput(inode);
goto out_stop;
}
ext4_inc_count(handle, dir);
ext4_update_dx_flag(dir);
err = ext4_mark_inode_dirty(handle, dir);
if (err)
goto out_clear_inode;
d_instantiate_new(dentry, inode);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
out_stop:
if (handle)
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
/*
* routine to check that the specified directory is empty (for rmdir)
*/
bool ext4_empty_dir(struct inode *inode)
{
unsigned int offset;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *de1;
struct super_block *sb;
if (ext4_has_inline_data(inode)) {
int has_inline_data = 1;
int ret;
ret = empty_inline_dir(inode, &has_inline_data);
if (has_inline_data)
return ret;
}
sb = inode->i_sb;
if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
EXT4_ERROR_INODE(inode, "invalid size");
return true;
}
bh = ext4_read_dirblock(inode, 0, EITHER);
if (IS_ERR(bh))
return true;
de = (struct ext4_dir_entry_2 *) bh->b_data;
de1 = ext4_next_entry(de, sb->s_blocksize);
if (le32_to_cpu(de->inode) != inode->i_ino ||
le32_to_cpu(de1->inode) == 0 ||
strcmp(".", de->name) || strcmp("..", de1->name)) {
ext4_warning_inode(inode, "directory missing '.' and/or '..'");
brelse(bh);
return true;
}
offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
de = ext4_next_entry(de1, sb->s_blocksize);
while (offset < inode->i_size) {
if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
unsigned int lblock;
brelse(bh);
lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
bh = ext4_read_dirblock(inode, lblock, EITHER);
if (IS_ERR(bh))
return true;
de = (struct ext4_dir_entry_2 *) bh->b_data;
}
if (ext4_check_dir_entry(inode, NULL, de, bh,
bh->b_data, bh->b_size, offset)) {
de = (struct ext4_dir_entry_2 *)(bh->b_data +
sb->s_blocksize);
offset = (offset | (sb->s_blocksize - 1)) + 1;
continue;
}
if (le32_to_cpu(de->inode)) {
brelse(bh);
return false;
}
offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
de = ext4_next_entry(de, sb->s_blocksize);
}
brelse(bh);
return true;
}
/*
* ext4_orphan_add() links an unlinked or truncated inode into a list of
* such inodes, starting at the superblock, in case we crash before the
* file is closed/deleted, or in case the inode truncate spans multiple
* transactions and the last transaction is not recovered after a crash.
*
* At filesystem recovery time, we walk this list deleting unlinked
* inodes and truncating linked inodes in ext4_orphan_cleanup().
*
* Orphan list manipulation functions must be called under i_mutex unless
* we are just creating the inode or deleting it.
*/
int ext4_orphan_add(handle_t *handle, struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
struct ext4_iloc iloc;
int err = 0, rc;
bool dirty = false;
if (!sbi->s_journal || is_bad_inode(inode))
return 0;
WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
!inode_is_locked(inode));
/*
* Exit early if inode already is on orphan list. This is a big speedup
* since we don't have to contend on the global s_orphan_lock.
*/
if (!list_empty(&EXT4_I(inode)->i_orphan))
return 0;
/*
* Orphan handling is only valid for files with data blocks
* being truncated, or files being unlinked. Note that we either
* hold i_mutex, or the inode can not be referenced from outside,
* so i_nlink should not be bumped due to race
*/
J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err)
goto out;
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err)
goto out;
mutex_lock(&sbi->s_orphan_lock);
/*
* Due to previous errors inode may be already a part of on-disk
* orphan list. If so skip on-disk list modification.
*/
if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
(le32_to_cpu(sbi->s_es->s_inodes_count))) {
/* Insert this inode at the head of the on-disk orphan list */
NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
dirty = true;
}
list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
mutex_unlock(&sbi->s_orphan_lock);
if (dirty) {
err = ext4_handle_dirty_super(handle, sb);
rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
if (!err)
err = rc;
if (err) {
/*
* We have to remove inode from in-memory list if
* addition to on disk orphan list failed. Stray orphan
* list entries can cause panics at unmount time.
*/
mutex_lock(&sbi->s_orphan_lock);
list_del_init(&EXT4_I(inode)->i_orphan);
mutex_unlock(&sbi->s_orphan_lock);
}
}
jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
jbd_debug(4, "orphan inode %lu will point to %d\n",
inode->i_ino, NEXT_ORPHAN(inode));
out:
ext4_std_error(sb, err);
return err;
}
/*
* ext4_orphan_del() removes an unlinked or truncated inode from the list
* of such inodes stored on disk, because it is finally being cleaned up.
*/
int ext4_orphan_del(handle_t *handle, struct inode *inode)
{
struct list_head *prev;
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
__u32 ino_next;
struct ext4_iloc iloc;
int err = 0;
if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
return 0;
WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
!inode_is_locked(inode));
/* Do this quick check before taking global s_orphan_lock. */
if (list_empty(&ei->i_orphan))
return 0;
if (handle) {
/* Grab inode buffer early before taking global s_orphan_lock */
err = ext4_reserve_inode_write(handle, inode, &iloc);
}
mutex_lock(&sbi->s_orphan_lock);
jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
prev = ei->i_orphan.prev;
list_del_init(&ei->i_orphan);
/* If we're on an error path, we may not have a valid
* transaction handle with which to update the orphan list on
* disk, but we still need to remove the inode from the linked
* list in memory. */
if (!handle || err) {
mutex_unlock(&sbi->s_orphan_lock);
goto out_err;
}
ino_next = NEXT_ORPHAN(inode);
if (prev == &sbi->s_orphan) {
jbd_debug(4, "superblock will point to %u\n", ino_next);
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err) {
mutex_unlock(&sbi->s_orphan_lock);
goto out_brelse;
}
sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
mutex_unlock(&sbi->s_orphan_lock);
err = ext4_handle_dirty_super(handle, inode->i_sb);
} else {
struct ext4_iloc iloc2;
struct inode *i_prev =
&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
jbd_debug(4, "orphan inode %lu will point to %u\n",
i_prev->i_ino, ino_next);
err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
if (err) {
mutex_unlock(&sbi->s_orphan_lock);
goto out_brelse;
}
NEXT_ORPHAN(i_prev) = ino_next;
err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
mutex_unlock(&sbi->s_orphan_lock);
}
if (err)
goto out_brelse;
NEXT_ORPHAN(inode) = 0;
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
out_err:
ext4_std_error(inode->i_sb, err);
return err;
out_brelse:
brelse(iloc.bh);
goto out_err;
}
static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
{
int retval;
struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
return -EIO;
/* Initialize quotas before so that eventual writes go in
* separate transaction */
retval = dquot_initialize(dir);
if (retval)
return retval;
retval = dquot_initialize(d_inode(dentry));
if (retval)
return retval;
retval = -ENOENT;
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (IS_ERR(bh))
return PTR_ERR(bh);
if (!bh)
goto end_rmdir;
inode = d_inode(dentry);
retval = -EFSCORRUPTED;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_rmdir;
retval = -ENOTEMPTY;
if (!ext4_empty_dir(inode))
goto end_rmdir;
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_rmdir;
}
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_rmdir;
if (!EXT4_DIR_LINK_EMPTY(inode))
ext4_warning_inode(inode,
"empty directory '%.*s' has too many links (%u)",
dentry->d_name.len, dentry->d_name.name,
inode->i_nlink);
inode_inc_iversion(inode);
clear_nlink(inode);
/* There's no need to set i_disksize: the fact that i_nlink is
* zero will ensure that the right thing happens during any
* recovery. */
inode->i_size = 0;
ext4_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
ext4_mark_inode_dirty(handle, inode);
ext4_dec_count(handle, dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
end_rmdir:
brelse(bh);
if (handle)
ext4_journal_stop(handle);
return retval;
}
static int ext4_unlink(struct inode *dir, struct dentry *dentry)
{
int retval;
struct inode *inode;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
handle_t *handle = NULL;
if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
return -EIO;
trace_ext4_unlink_enter(dir, dentry);
/* Initialize quotas before so that eventual writes go
* in separate transaction */
retval = dquot_initialize(dir);
if (retval)
return retval;
retval = dquot_initialize(d_inode(dentry));
if (retval)
return retval;
retval = -ENOENT;
bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
if (IS_ERR(bh))
return PTR_ERR(bh);
if (!bh)
goto end_unlink;
inode = d_inode(dentry);
retval = -EFSCORRUPTED;
if (le32_to_cpu(de->inode) != inode->i_ino)
goto end_unlink;
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_unlink;
}
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
if (inode->i_nlink == 0) {
ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
dentry->d_name.len, dentry->d_name.name);
set_nlink(inode, 1);
}
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = current_time(dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
drop_nlink(inode);
if (!inode->i_nlink)
ext4_orphan_add(handle, inode);
inode->i_ctime = current_time(inode);
ext4_mark_inode_dirty(handle, inode);
end_unlink:
brelse(bh);
if (handle)
ext4_journal_stop(handle);
trace_ext4_unlink_exit(dentry, retval);
return retval;
}
static int ext4_symlink(struct inode *dir,
struct dentry *dentry, const char *symname)
{
handle_t *handle;
struct inode *inode;
int err, len = strlen(symname);
int credits;
struct fscrypt_str disk_link;
if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
return -EIO;
err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
&disk_link);
if (err)
return err;
err = dquot_initialize(dir);
if (err)
return err;
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
/*
* For non-fast symlinks, we just allocate inode and put it on
* orphan list in the first transaction => we need bitmap,
* group descriptor, sb, inode block, quota blocks, and
* possibly selinux xattr blocks.
*/
credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
EXT4_XATTR_TRANS_BLOCKS;
} else {
/*
* Fast symlink. We have to add entry to directory
* (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
* allocate new inode (bitmap, group descriptor, inode block,
* quota blocks, sb is already counted in previous macros).
*/
credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
}
inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
&dentry->d_name, 0, NULL,
EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
if (IS_ERR(inode)) {
if (handle)
ext4_journal_stop(handle);
return PTR_ERR(inode);
}
if (IS_ENCRYPTED(inode)) {
err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
if (err)
goto err_drop_inode;
inode->i_op = &ext4_encrypted_symlink_inode_operations;
}
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
if (!IS_ENCRYPTED(inode))
inode->i_op = &ext4_symlink_inode_operations;
inode_nohighmem(inode);
ext4_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
* because it calls into ext4_write_begin() which can wait
* for transaction commit if we are running out of space
* and thus we deadlock. So we have to stop transaction now
* and restart it when symlink contents is written.
*
* To keep fs consistent in case of crash, we have to put inode
* to orphan list in the mean time.
*/
drop_nlink(inode);
err = ext4_orphan_add(handle, inode);
ext4_journal_stop(handle);
handle = NULL;
if (err)
goto err_drop_inode;
err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
if (err)
goto err_drop_inode;
/*
* Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
* + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
*/
handle = ext4_journal_start(dir, EXT4_HT_DIR,
EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
handle = NULL;
goto err_drop_inode;
}
set_nlink(inode, 1);
err = ext4_orphan_del(handle, inode);
if (err)
goto err_drop_inode;
} else {
/* clear the extent format for fast symlink */
ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
if (!IS_ENCRYPTED(inode)) {
inode->i_op = &ext4_fast_symlink_inode_operations;
inode->i_link = (char *)&EXT4_I(inode)->i_data;
}
memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
disk_link.len);
inode->i_size = disk_link.len - 1;
}
EXT4_I(inode)->i_disksize = inode->i_size;
err = ext4_add_nondir(handle, dentry, inode);
if (!err && IS_DIRSYNC(dir))
ext4_handle_sync(handle);
if (handle)
ext4_journal_stop(handle);
goto out_free_encrypted_link;
err_drop_inode:
if (handle)
ext4_journal_stop(handle);
clear_nlink(inode);
unlock_new_inode(inode);
iput(inode);
out_free_encrypted_link:
if (disk_link.name != (unsigned char *)symname)
kfree(disk_link.name);
return err;
}
static int ext4_link(struct dentry *old_dentry,
struct inode *dir, struct dentry *dentry)
{
handle_t *handle;
struct inode *inode = d_inode(old_dentry);
int err, retries = 0;
if (inode->i_nlink >= EXT4_LINK_MAX)
return -EMLINK;
err = fscrypt_prepare_link(old_dentry, dir, dentry);
if (err)
return err;
if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
(!projid_eq(EXT4_I(dir)->i_projid,
EXT4_I(old_dentry->d_inode)->i_projid)))
return -EXDEV;
err = dquot_initialize(dir);
if (err)
return err;
retry:
handle = ext4_journal_start(dir, EXT4_HT_DIR,
(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
inode->i_ctime = current_time(inode);
ext4_inc_count(handle, inode);
ihold(inode);
err = ext4_add_entry(handle, dentry, inode);
if (!err) {
ext4_mark_inode_dirty(handle, inode);
/* this can happen only for tmpfile being
* linked the first time
*/
if (inode->i_nlink == 1)
ext4_orphan_del(handle, inode);
d_instantiate(dentry, inode);
} else {
drop_nlink(inode);
iput(inode);
}
ext4_journal_stop(handle);
if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
goto retry;
return err;
}
/*
* Try to find buffer head where contains the parent block.
* It should be the inode block if it is inlined or the 1st block
* if it is a normal dir.
*/
static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
struct inode *inode,
int *retval,
struct ext4_dir_entry_2 **parent_de,
int *inlined)
{
struct buffer_head *bh;
if (!ext4_has_inline_data(inode)) {
bh = ext4_read_dirblock(inode, 0, EITHER);
if (IS_ERR(bh)) {
*retval = PTR_ERR(bh);
return NULL;
}
*parent_de = ext4_next_entry(
(struct ext4_dir_entry_2 *)bh->b_data,
inode->i_sb->s_blocksize);
return bh;
}
*inlined = 1;
return ext4_get_first_inline_block(inode, parent_de, retval);
}
struct ext4_renament {
struct inode *dir;
struct dentry *dentry;
struct inode *inode;
bool is_dir;
int dir_nlink_delta;
/* entry for "dentry" */
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
int inlined;
/* entry for ".." in inode if it's a directory */
struct buffer_head *dir_bh;
struct ext4_dir_entry_2 *parent_de;
int dir_inlined;
};
static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
{
int retval;
ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
&retval, &ent->parent_de,
&ent->dir_inlined);
if (!ent->dir_bh)
return retval;
if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
return -EFSCORRUPTED;
BUFFER_TRACE(ent->dir_bh, "get_write_access");
return ext4_journal_get_write_access(handle, ent->dir_bh);
}
static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
unsigned dir_ino)
{
int retval;
ent->parent_de->inode = cpu_to_le32(dir_ino);
BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
if (!ent->dir_inlined) {
if (is_dx(ent->inode)) {
retval = ext4_handle_dirty_dx_node(handle,
ent->inode,
ent->dir_bh);
} else {
retval = ext4_handle_dirty_dirent_node(handle,
ent->inode,
ent->dir_bh);
}
} else {
retval = ext4_mark_inode_dirty(handle, ent->inode);
}
if (retval) {
ext4_std_error(ent->dir->i_sb, retval);
return retval;
}
return 0;
}
static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
unsigned ino, unsigned file_type)
{
int retval;
BUFFER_TRACE(ent->bh, "get write access");
retval = ext4_journal_get_write_access(handle, ent->bh);
if (retval)
return retval;
ent->de->inode = cpu_to_le32(ino);
if (ext4_has_feature_filetype(ent->dir->i_sb))
ent->de->file_type = file_type;
inode_inc_iversion(ent->dir);
ent->dir->i_ctime = ent->dir->i_mtime =
current_time(ent->dir);
ext4_mark_inode_dirty(handle, ent->dir);
BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
if (!ent->inlined) {
retval = ext4_handle_dirty_dirent_node(handle,
ent->dir, ent->bh);
if (unlikely(retval)) {
ext4_std_error(ent->dir->i_sb, retval);
return retval;
}
}
brelse(ent->bh);
ent->bh = NULL;
return 0;
}
static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
const struct qstr *d_name)
{
int retval = -ENOENT;
struct buffer_head *bh;
struct ext4_dir_entry_2 *de;
bh = ext4_find_entry(dir, d_name, &de, NULL);
if (IS_ERR(bh))
return PTR_ERR(bh);
if (bh) {
retval = ext4_delete_entry(handle, dir, de, bh);
brelse(bh);
}
return retval;
}
static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
int force_reread)
{
int retval;
/*
* ent->de could have moved from under us during htree split, so make
* sure that we are deleting the right entry. We might also be pointing
* to a stale entry in the unused part of ent->bh so just checking inum
* and the name isn't enough.
*/
if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
ent->de->name_len != ent->dentry->d_name.len ||
strncmp(ent->de->name, ent->dentry->d_name.name,
ent->de->name_len) ||
force_reread) {
retval = ext4_find_delete_entry(handle, ent->dir,
&ent->dentry->d_name);
} else {
retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
if (retval == -ENOENT) {
retval = ext4_find_delete_entry(handle, ent->dir,
&ent->dentry->d_name);
}
}
if (retval) {
ext4_warning_inode(ent->dir,
"Deleting old file: nlink %d, error=%d",
ent->dir->i_nlink, retval);
}
}
static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
{
if (ent->dir_nlink_delta) {
if (ent->dir_nlink_delta == -1)
ext4_dec_count(handle, ent->dir);
else
ext4_inc_count(handle, ent->dir);
ext4_mark_inode_dirty(handle, ent->dir);
}
}
static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
int credits, handle_t **h)
{
struct inode *wh;
handle_t *handle;
int retries = 0;
/*
* for inode block, sb block, group summaries,
* and inode bitmap
*/
credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
EXT4_XATTR_TRANS_BLOCKS + 4);
retry:
wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
&ent->dentry->d_name, 0, NULL,
EXT4_HT_DIR, credits);
handle = ext4_journal_current_handle();
if (IS_ERR(wh)) {
if (handle)
ext4_journal_stop(handle);
if (PTR_ERR(wh) == -ENOSPC &&
ext4_should_retry_alloc(ent->dir->i_sb, &retries))
goto retry;
} else {
*h = handle;
init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
wh->i_op = &ext4_special_inode_operations;
}
return wh;
}
/*
* Anybody can rename anything with this: the permission checks are left to the
* higher-level routines.
*
* n.b. old_{dentry,inode) refers to the source dentry/inode
* while new_{dentry,inode) refers to the destination dentry/inode
* This comes from rename(const char *oldpath, const char *newpath)
*/
static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
handle_t *handle = NULL;
struct ext4_renament old = {
.dir = old_dir,
.dentry = old_dentry,
.inode = d_inode(old_dentry),
};
struct ext4_renament new = {
.dir = new_dir,
.dentry = new_dentry,
.inode = d_inode(new_dentry),
};
int force_reread;
int retval;
struct inode *whiteout = NULL;
int credits;
u8 old_file_type;
if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
(!projid_eq(EXT4_I(new_dir)->i_projid,
EXT4_I(old_dentry->d_inode)->i_projid)))
return -EXDEV;
retval = dquot_initialize(old.dir);
if (retval)
return retval;
retval = dquot_initialize(new.dir);
if (retval)
return retval;
/* Initialize quotas before so that eventual writes go
* in separate transaction */
if (new.inode) {
retval = dquot_initialize(new.inode);
if (retval)
return retval;
}
old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
if (IS_ERR(old.bh))
return PTR_ERR(old.bh);
/*
* Check for inode number is _not_ due to possible IO errors.
* We might rmdir the source, keep it as pwd of some process
* and merrily kill the link to whatever was created under the
* same name. Goodbye sticky bit ;-<
*/
retval = -ENOENT;
if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
goto end_rename;
new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
&new.de, &new.inlined);
if (IS_ERR(new.bh)) {
retval = PTR_ERR(new.bh);
new.bh = NULL;
goto end_rename;
}
if (new.bh) {
if (!new.inode) {
brelse(new.bh);
new.bh = NULL;
}
}
if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
ext4_alloc_da_blocks(old.inode);
credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
if (!(flags & RENAME_WHITEOUT)) {
handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_rename;
}
} else {
whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
if (IS_ERR(whiteout)) {
retval = PTR_ERR(whiteout);
whiteout = NULL;
goto end_rename;
}
}
if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
ext4_handle_sync(handle);
if (S_ISDIR(old.inode->i_mode)) {
if (new.inode) {
retval = -ENOTEMPTY;
if (!ext4_empty_dir(new.inode))
goto end_rename;
} else {
retval = -EMLINK;
if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
goto end_rename;
}
retval = ext4_rename_dir_prepare(handle, &old);
if (retval)
goto end_rename;
}
/*
* If we're renaming a file within an inline_data dir and adding or
* setting the new dirent causes a conversion from inline_data to
* extents/blockmap, we need to force the dirent delete code to
* re-read the directory, or else we end up trying to delete a dirent
* from what is now the extent tree root (or a block map).
*/
force_reread = (new.dir->i_ino == old.dir->i_ino &&
ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
old_file_type = old.de->file_type;
if (whiteout) {
/*
* Do this before adding a new entry, so the old entry is sure
* to be still pointing to the valid old entry.
*/
retval = ext4_setent(handle, &old, whiteout->i_ino,
EXT4_FT_CHRDEV);
if (retval)
goto end_rename;
ext4_mark_inode_dirty(handle, whiteout);
}
if (!new.bh) {
retval = ext4_add_entry(handle, new.dentry, old.inode);
if (retval)
goto end_rename;
} else {
retval = ext4_setent(handle, &new,
old.inode->i_ino, old_file_type);
if (retval)
goto end_rename;
}
if (force_reread)
force_reread = !ext4_test_inode_flag(new.dir,
EXT4_INODE_INLINE_DATA);
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
old.inode->i_ctime = current_time(old.inode);
ext4_mark_inode_dirty(handle, old.inode);
if (!whiteout) {
/*
* ok, that's it
*/
ext4_rename_delete(handle, &old, force_reread);
}
if (new.inode) {
ext4_dec_count(handle, new.inode);
new.inode->i_ctime = current_time(new.inode);
}
old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
ext4_update_dx_flag(old.dir);
if (old.dir_bh) {
retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
if (retval)
goto end_rename;
ext4_dec_count(handle, old.dir);
if (new.inode) {
/* checked ext4_empty_dir above, can't have another
* parent, ext4_dec_count() won't work for many-linked
* dirs */
clear_nlink(new.inode);
} else {
ext4_inc_count(handle, new.dir);
ext4_update_dx_flag(new.dir);
ext4_mark_inode_dirty(handle, new.dir);
}
}
ext4_mark_inode_dirty(handle, old.dir);
if (new.inode) {
ext4_mark_inode_dirty(handle, new.inode);
if (!new.inode->i_nlink)
ext4_orphan_add(handle, new.inode);
}
retval = 0;
end_rename:
brelse(old.dir_bh);
brelse(old.bh);
brelse(new.bh);
if (whiteout) {
if (retval)
drop_nlink(whiteout);
unlock_new_inode(whiteout);
iput(whiteout);
}
if (handle)
ext4_journal_stop(handle);
return retval;
}
static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
handle_t *handle = NULL;
struct ext4_renament old = {
.dir = old_dir,
.dentry = old_dentry,
.inode = d_inode(old_dentry),
};
struct ext4_renament new = {
.dir = new_dir,
.dentry = new_dentry,
.inode = d_inode(new_dentry),
};
u8 new_file_type;
int retval;
struct timespec64 ctime;
if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
!projid_eq(EXT4_I(new_dir)->i_projid,
EXT4_I(old_dentry->d_inode)->i_projid)) ||
(ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
!projid_eq(EXT4_I(old_dir)->i_projid,
EXT4_I(new_dentry->d_inode)->i_projid)))
return -EXDEV;
retval = dquot_initialize(old.dir);
if (retval)
return retval;
retval = dquot_initialize(new.dir);
if (retval)
return retval;
old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
&old.de, &old.inlined);
if (IS_ERR(old.bh))
return PTR_ERR(old.bh);
/*
* Check for inode number is _not_ due to possible IO errors.
* We might rmdir the source, keep it as pwd of some process
* and merrily kill the link to whatever was created under the
* same name. Goodbye sticky bit ;-<
*/
retval = -ENOENT;
if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
goto end_rename;
new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
&new.de, &new.inlined);
if (IS_ERR(new.bh)) {
retval = PTR_ERR(new.bh);
new.bh = NULL;
goto end_rename;
}
/* RENAME_EXCHANGE case: old *and* new must both exist */
if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
goto end_rename;
handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
if (IS_ERR(handle)) {
retval = PTR_ERR(handle);
handle = NULL;
goto end_rename;
}
if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
ext4_handle_sync(handle);
if (S_ISDIR(old.inode->i_mode)) {
old.is_dir = true;
retval = ext4_rename_dir_prepare(handle, &old);
if (retval)
goto end_rename;
}
if (S_ISDIR(new.inode->i_mode)) {
new.is_dir = true;
retval = ext4_rename_dir_prepare(handle, &new);
if (retval)
goto end_rename;
}
/*
* Other than the special case of overwriting a directory, parents'
* nlink only needs to be modified if this is a cross directory rename.
*/
if (old.dir != new.dir && old.is_dir != new.is_dir) {
old.dir_nlink_delta = old.is_dir ? -1 : 1;
new.dir_nlink_delta = -old.dir_nlink_delta;
retval = -EMLINK;
if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
(new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
goto end_rename;
}
new_file_type = new.de->file_type;
retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
if (retval)
goto end_rename;
retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
if (retval)
goto end_rename;
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
ctime = current_time(old.inode);
old.inode->i_ctime = ctime;
new.inode->i_ctime = ctime;
ext4_mark_inode_dirty(handle, old.inode);
ext4_mark_inode_dirty(handle, new.inode);
if (old.dir_bh) {
retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
if (retval)
goto end_rename;
}
if (new.dir_bh) {
retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
if (retval)
goto end_rename;
}
ext4_update_dir_count(handle, &old);
ext4_update_dir_count(handle, &new);
retval = 0;
end_rename:
brelse(old.dir_bh);
brelse(new.dir_bh);
brelse(old.bh);
brelse(new.bh);
if (handle)
ext4_journal_stop(handle);
return retval;
}
static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
int err;
if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
return -EIO;
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
return -EINVAL;
err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
flags);
if (err)
return err;
if (flags & RENAME_EXCHANGE) {
return ext4_cross_rename(old_dir, old_dentry,
new_dir, new_dentry);
}
return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
}
/*
* directories can handle most operations...
*/
const struct inode_operations ext4_dir_inode_operations = {
.create = ext4_create,
.lookup = ext4_lookup,
.link = ext4_link,
.unlink = ext4_unlink,
.symlink = ext4_symlink,
.mkdir = ext4_mkdir,
.rmdir = ext4_rmdir,
.mknod = ext4_mknod,
.tmpfile = ext4_tmpfile,
.rename = ext4_rename2,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
.fiemap = ext4_fiemap,
};
const struct inode_operations ext4_special_inode_operations = {
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
};
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