linux/fs/fat/inode.c
Namjae Jeon 2628b7a6ac fat: introduce 2 new values for the -o nfs mount option
This patchset eliminates the client side ESTALE errors when a FAT
partition exported over NFS has its dentries evicted from the cache.  The
idea is to find the on-disk location_'i_pos' of the dirent of the inode
that has been evicted and use it to rebuild the inode.

This patch:

Provide two possible values 'stale_rw' and 'nostale_ro' for the -o nfs
mount option.The first one allows all file operations but does not reduce
ESTALE errors on memory constrained systems.  The second one eliminates
ESTALE errors but mounts the filesystem as read-only.  Not specifying a
value defaults to 'stale_rw'.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ravishankar N <ravi.n1@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 18:28:40 -07:00

1631 lines
42 KiB
C

/*
* linux/fs/fat/inode.c
*
* Written 1992,1993 by Werner Almesberger
* VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
* Rewritten for the constant inumbers support by Al Viro
*
* Fixes:
*
* Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/mount.h>
#include <linux/vfs.h>
#include <linux/parser.h>
#include <linux/uio.h>
#include <linux/writeback.h>
#include <linux/log2.h>
#include <linux/hash.h>
#include <linux/blkdev.h>
#include <asm/unaligned.h>
#include "fat.h"
#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
/* if user don't select VFAT, this is undefined. */
#define CONFIG_FAT_DEFAULT_IOCHARSET ""
#endif
static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
static int fat_add_cluster(struct inode *inode)
{
int err, cluster;
err = fat_alloc_clusters(inode, &cluster, 1);
if (err)
return err;
/* FIXME: this cluster should be added after data of this
* cluster is writed */
err = fat_chain_add(inode, cluster, 1);
if (err)
fat_free_clusters(inode, cluster);
return err;
}
static inline int __fat_get_block(struct inode *inode, sector_t iblock,
unsigned long *max_blocks,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
unsigned long mapped_blocks;
sector_t phys;
int err, offset;
err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
if (err)
return err;
if (phys) {
map_bh(bh_result, sb, phys);
*max_blocks = min(mapped_blocks, *max_blocks);
return 0;
}
if (!create)
return 0;
if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
return -EIO;
}
offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
if (!offset) {
/* TODO: multiple cluster allocation would be desirable. */
err = fat_add_cluster(inode);
if (err)
return err;
}
/* available blocks on this cluster */
mapped_blocks = sbi->sec_per_clus - offset;
*max_blocks = min(mapped_blocks, *max_blocks);
MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
if (err)
return err;
BUG_ON(!phys);
BUG_ON(*max_blocks != mapped_blocks);
set_buffer_new(bh_result);
map_bh(bh_result, sb, phys);
return 0;
}
static int fat_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
int err;
err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
if (err)
return err;
bh_result->b_size = max_blocks << sb->s_blocksize_bits;
return 0;
}
static int fat_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, fat_get_block, wbc);
}
static int fat_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, fat_get_block);
}
static int fat_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, fat_get_block);
}
static int fat_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
}
static void fat_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
truncate_pagecache(inode, to, inode->i_size);
fat_truncate_blocks(inode, inode->i_size);
}
}
static int fat_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int err;
*pagep = NULL;
err = cont_write_begin(file, mapping, pos, len, flags,
pagep, fsdata, fat_get_block,
&MSDOS_I(mapping->host)->mmu_private);
if (err < 0)
fat_write_failed(mapping, pos + len);
return err;
}
static int fat_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *pagep, void *fsdata)
{
struct inode *inode = mapping->host;
int err;
err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
if (err < len)
fat_write_failed(mapping, pos + len);
if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
mark_inode_dirty(inode);
}
return err;
}
static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
const struct iovec *iov,
loff_t offset, unsigned long nr_segs)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
ssize_t ret;
if (rw == WRITE) {
/*
* FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
* so we need to update the ->mmu_private to block boundary.
*
* But we must fill the remaining area or hole by nul for
* updating ->mmu_private.
*
* Return 0, and fallback to normal buffered write.
*/
loff_t size = offset + iov_length(iov, nr_segs);
if (MSDOS_I(inode)->mmu_private < size)
return 0;
}
/*
* FAT need to use the DIO_LOCKING for avoiding the race
* condition of fat_get_block() and ->truncate().
*/
ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
fat_get_block);
if (ret < 0 && (rw & WRITE))
fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
return ret;
}
static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
{
sector_t blocknr;
/* fat_get_cluster() assumes the requested blocknr isn't truncated. */
down_read(&MSDOS_I(mapping->host)->truncate_lock);
blocknr = generic_block_bmap(mapping, block, fat_get_block);
up_read(&MSDOS_I(mapping->host)->truncate_lock);
return blocknr;
}
static const struct address_space_operations fat_aops = {
.readpage = fat_readpage,
.readpages = fat_readpages,
.writepage = fat_writepage,
.writepages = fat_writepages,
.write_begin = fat_write_begin,
.write_end = fat_write_end,
.direct_IO = fat_direct_IO,
.bmap = _fat_bmap
};
/*
* New FAT inode stuff. We do the following:
* a) i_ino is constant and has nothing with on-disk location.
* b) FAT manages its own cache of directory entries.
* c) *This* cache is indexed by on-disk location.
* d) inode has an associated directory entry, all right, but
* it may be unhashed.
* e) currently entries are stored within struct inode. That should
* change.
* f) we deal with races in the following way:
* 1. readdir() and lookup() do FAT-dir-cache lookup.
* 2. rename() unhashes the F-d-c entry and rehashes it in
* a new place.
* 3. unlink() and rmdir() unhash F-d-c entry.
* 4. fat_write_inode() checks whether the thing is unhashed.
* If it is we silently return. If it isn't we do bread(),
* check if the location is still valid and retry if it
* isn't. Otherwise we do changes.
* 5. Spinlock is used to protect hash/unhash/location check/lookup
* 6. fat_evict_inode() unhashes the F-d-c entry.
* 7. lookup() and readdir() do igrab() if they find a F-d-c entry
* and consider negative result as cache miss.
*/
static void fat_hash_init(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
int i;
spin_lock_init(&sbi->inode_hash_lock);
for (i = 0; i < FAT_HASH_SIZE; i++)
INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
}
static inline unsigned long fat_hash(loff_t i_pos)
{
return hash_32(i_pos, FAT_HASH_BITS);
}
static void dir_hash_init(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
int i;
spin_lock_init(&sbi->dir_hash_lock);
for (i = 0; i < FAT_HASH_SIZE; i++)
INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
}
void fat_attach(struct inode *inode, loff_t i_pos)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
if (inode->i_ino != MSDOS_ROOT_INO) {
struct hlist_head *head = sbi->inode_hashtable
+ fat_hash(i_pos);
spin_lock(&sbi->inode_hash_lock);
MSDOS_I(inode)->i_pos = i_pos;
hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
spin_unlock(&sbi->inode_hash_lock);
}
/* If NFS support is enabled, cache the mapping of start cluster
* to directory inode. This is used during reconnection of
* dentries to the filesystem root.
*/
if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
struct hlist_head *d_head = sbi->dir_hashtable;
d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
spin_lock(&sbi->dir_hash_lock);
hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
spin_unlock(&sbi->dir_hash_lock);
}
}
EXPORT_SYMBOL_GPL(fat_attach);
void fat_detach(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
spin_lock(&sbi->inode_hash_lock);
MSDOS_I(inode)->i_pos = 0;
hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
spin_unlock(&sbi->inode_hash_lock);
if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
spin_lock(&sbi->dir_hash_lock);
hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
spin_unlock(&sbi->dir_hash_lock);
}
}
EXPORT_SYMBOL_GPL(fat_detach);
struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
struct msdos_inode_info *i;
struct inode *inode = NULL;
spin_lock(&sbi->inode_hash_lock);
hlist_for_each_entry(i, head, i_fat_hash) {
BUG_ON(i->vfs_inode.i_sb != sb);
if (i->i_pos != i_pos)
continue;
inode = igrab(&i->vfs_inode);
if (inode)
break;
}
spin_unlock(&sbi->inode_hash_lock);
return inode;
}
static int is_exec(unsigned char *extension)
{
unsigned char *exe_extensions = "EXECOMBAT", *walk;
for (walk = exe_extensions; *walk; walk += 3)
if (!strncmp(extension, walk, 3))
return 1;
return 0;
}
static int fat_calc_dir_size(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
int ret, fclus, dclus;
inode->i_size = 0;
if (MSDOS_I(inode)->i_start == 0)
return 0;
ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
if (ret < 0)
return ret;
inode->i_size = (fclus + 1) << sbi->cluster_bits;
return 0;
}
/* doesn't deal with root inode */
static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
int error;
MSDOS_I(inode)->i_pos = 0;
inode->i_uid = sbi->options.fs_uid;
inode->i_gid = sbi->options.fs_gid;
inode->i_version++;
inode->i_generation = get_seconds();
if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
inode->i_generation &= ~1;
inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
inode->i_op = sbi->dir_ops;
inode->i_fop = &fat_dir_operations;
MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
error = fat_calc_dir_size(inode);
if (error < 0)
return error;
MSDOS_I(inode)->mmu_private = inode->i_size;
set_nlink(inode, fat_subdirs(inode));
} else { /* not a directory */
inode->i_generation |= 1;
inode->i_mode = fat_make_mode(sbi, de->attr,
((sbi->options.showexec && !is_exec(de->name + 8))
? S_IRUGO|S_IWUGO : S_IRWXUGO));
MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
inode->i_size = le32_to_cpu(de->size);
inode->i_op = &fat_file_inode_operations;
inode->i_fop = &fat_file_operations;
inode->i_mapping->a_ops = &fat_aops;
MSDOS_I(inode)->mmu_private = inode->i_size;
}
if (de->attr & ATTR_SYS) {
if (sbi->options.sys_immutable)
inode->i_flags |= S_IMMUTABLE;
}
fat_save_attrs(inode, de->attr);
inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
& ~((loff_t)sbi->cluster_size - 1)) >> 9;
fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
if (sbi->options.isvfat) {
fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
de->cdate, de->ctime_cs);
fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
} else
inode->i_ctime = inode->i_atime = inode->i_mtime;
return 0;
}
struct inode *fat_build_inode(struct super_block *sb,
struct msdos_dir_entry *de, loff_t i_pos)
{
struct inode *inode;
int err;
inode = fat_iget(sb, i_pos);
if (inode)
goto out;
inode = new_inode(sb);
if (!inode) {
inode = ERR_PTR(-ENOMEM);
goto out;
}
inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
inode->i_version = 1;
err = fat_fill_inode(inode, de);
if (err) {
iput(inode);
inode = ERR_PTR(err);
goto out;
}
fat_attach(inode, i_pos);
insert_inode_hash(inode);
out:
return inode;
}
EXPORT_SYMBOL_GPL(fat_build_inode);
static void fat_evict_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
if (!inode->i_nlink) {
inode->i_size = 0;
fat_truncate_blocks(inode, 0);
}
invalidate_inode_buffers(inode);
clear_inode(inode);
fat_cache_inval_inode(inode);
fat_detach(inode);
}
static void fat_set_state(struct super_block *sb,
unsigned int set, unsigned int force)
{
struct buffer_head *bh;
struct fat_boot_sector *b;
struct msdos_sb_info *sbi = sb->s_fs_info;
/* do not change any thing if mounted read only */
if ((sb->s_flags & MS_RDONLY) && !force)
return;
/* do not change state if fs was dirty */
if (sbi->dirty) {
/* warn only on set (mount). */
if (set)
fat_msg(sb, KERN_WARNING, "Volume was not properly "
"unmounted. Some data may be corrupt. "
"Please run fsck.");
return;
}
bh = sb_bread(sb, 0);
if (bh == NULL) {
fat_msg(sb, KERN_ERR, "unable to read boot sector "
"to mark fs as dirty");
return;
}
b = (struct fat_boot_sector *) bh->b_data;
if (sbi->fat_bits == 32) {
if (set)
b->fat32.state |= FAT_STATE_DIRTY;
else
b->fat32.state &= ~FAT_STATE_DIRTY;
} else /* fat 16 and 12 */ {
if (set)
b->fat16.state |= FAT_STATE_DIRTY;
else
b->fat16.state &= ~FAT_STATE_DIRTY;
}
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
brelse(bh);
}
static void fat_put_super(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
fat_set_state(sb, 0, 0);
iput(sbi->fsinfo_inode);
iput(sbi->fat_inode);
unload_nls(sbi->nls_disk);
unload_nls(sbi->nls_io);
if (sbi->options.iocharset != fat_default_iocharset)
kfree(sbi->options.iocharset);
sb->s_fs_info = NULL;
kfree(sbi);
}
static struct kmem_cache *fat_inode_cachep;
static struct inode *fat_alloc_inode(struct super_block *sb)
{
struct msdos_inode_info *ei;
ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
init_rwsem(&ei->truncate_lock);
return &ei->vfs_inode;
}
static void fat_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
}
static void fat_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, fat_i_callback);
}
static void init_once(void *foo)
{
struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
spin_lock_init(&ei->cache_lru_lock);
ei->nr_caches = 0;
ei->cache_valid_id = FAT_CACHE_VALID + 1;
INIT_LIST_HEAD(&ei->cache_lru);
INIT_HLIST_NODE(&ei->i_fat_hash);
INIT_HLIST_NODE(&ei->i_dir_hash);
inode_init_once(&ei->vfs_inode);
}
static int __init fat_init_inodecache(void)
{
fat_inode_cachep = kmem_cache_create("fat_inode_cache",
sizeof(struct msdos_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (fat_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void __exit fat_destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(fat_inode_cachep);
}
static int fat_remount(struct super_block *sb, int *flags, char *data)
{
int new_rdonly;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
*flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
/* make sure we update state on remount. */
new_rdonly = *flags & MS_RDONLY;
if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
if (new_rdonly)
fat_set_state(sb, 0, 0);
else
fat_set_state(sb, 1, 1);
}
return 0;
}
static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
/* If the count of free cluster is still unknown, counts it here. */
if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
int err = fat_count_free_clusters(dentry->d_sb);
if (err)
return err;
}
buf->f_type = dentry->d_sb->s_magic;
buf->f_bsize = sbi->cluster_size;
buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
buf->f_bfree = sbi->free_clusters;
buf->f_bavail = sbi->free_clusters;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen =
(sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
return 0;
}
static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
struct inode *inode)
{
loff_t i_pos;
#if BITS_PER_LONG == 32
spin_lock(&sbi->inode_hash_lock);
#endif
i_pos = MSDOS_I(inode)->i_pos;
#if BITS_PER_LONG == 32
spin_unlock(&sbi->inode_hash_lock);
#endif
return i_pos;
}
static int __fat_write_inode(struct inode *inode, int wait)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
struct msdos_dir_entry *raw_entry;
loff_t i_pos;
int err;
if (inode->i_ino == MSDOS_ROOT_INO)
return 0;
retry:
i_pos = fat_i_pos_read(sbi, inode);
if (!i_pos)
return 0;
bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
if (!bh) {
fat_msg(sb, KERN_ERR, "unable to read inode block "
"for updating (i_pos %lld)", i_pos);
return -EIO;
}
spin_lock(&sbi->inode_hash_lock);
if (i_pos != MSDOS_I(inode)->i_pos) {
spin_unlock(&sbi->inode_hash_lock);
brelse(bh);
goto retry;
}
raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
[i_pos & (sbi->dir_per_block - 1)];
if (S_ISDIR(inode->i_mode))
raw_entry->size = 0;
else
raw_entry->size = cpu_to_le32(inode->i_size);
raw_entry->attr = fat_make_attrs(inode);
fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
&raw_entry->date, NULL);
if (sbi->options.isvfat) {
__le16 atime;
fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
&raw_entry->cdate, &raw_entry->ctime_cs);
fat_time_unix2fat(sbi, &inode->i_atime, &atime,
&raw_entry->adate, NULL);
}
spin_unlock(&sbi->inode_hash_lock);
mark_buffer_dirty(bh);
err = 0;
if (wait)
err = sync_dirty_buffer(bh);
brelse(bh);
return err;
}
static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
{
int err;
if (inode->i_ino == MSDOS_FSINFO_INO) {
struct super_block *sb = inode->i_sb;
mutex_lock(&MSDOS_SB(sb)->s_lock);
err = fat_clusters_flush(sb);
mutex_unlock(&MSDOS_SB(sb)->s_lock);
} else
err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
return err;
}
int fat_sync_inode(struct inode *inode)
{
return __fat_write_inode(inode, 1);
}
EXPORT_SYMBOL_GPL(fat_sync_inode);
static int fat_show_options(struct seq_file *m, struct dentry *root);
static const struct super_operations fat_sops = {
.alloc_inode = fat_alloc_inode,
.destroy_inode = fat_destroy_inode,
.write_inode = fat_write_inode,
.evict_inode = fat_evict_inode,
.put_super = fat_put_super,
.statfs = fat_statfs,
.remount_fs = fat_remount,
.show_options = fat_show_options,
};
static const struct export_operations fat_export_ops = {
.fh_to_dentry = fat_fh_to_dentry,
.fh_to_parent = fat_fh_to_parent,
.get_parent = fat_get_parent,
};
static int fat_show_options(struct seq_file *m, struct dentry *root)
{
struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
struct fat_mount_options *opts = &sbi->options;
int isvfat = opts->isvfat;
if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
seq_printf(m, ",uid=%u",
from_kuid_munged(&init_user_ns, opts->fs_uid));
if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
seq_printf(m, ",gid=%u",
from_kgid_munged(&init_user_ns, opts->fs_gid));
seq_printf(m, ",fmask=%04o", opts->fs_fmask);
seq_printf(m, ",dmask=%04o", opts->fs_dmask);
if (opts->allow_utime)
seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
if (sbi->nls_disk)
/* strip "cp" prefix from displayed option */
seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
if (isvfat) {
if (sbi->nls_io)
seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
switch (opts->shortname) {
case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
seq_puts(m, ",shortname=win95");
break;
case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
seq_puts(m, ",shortname=winnt");
break;
case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
seq_puts(m, ",shortname=mixed");
break;
case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
seq_puts(m, ",shortname=lower");
break;
default:
seq_puts(m, ",shortname=unknown");
break;
}
}
if (opts->name_check != 'n')
seq_printf(m, ",check=%c", opts->name_check);
if (opts->usefree)
seq_puts(m, ",usefree");
if (opts->quiet)
seq_puts(m, ",quiet");
if (opts->showexec)
seq_puts(m, ",showexec");
if (opts->sys_immutable)
seq_puts(m, ",sys_immutable");
if (!isvfat) {
if (opts->dotsOK)
seq_puts(m, ",dotsOK=yes");
if (opts->nocase)
seq_puts(m, ",nocase");
} else {
if (opts->utf8)
seq_puts(m, ",utf8");
if (opts->unicode_xlate)
seq_puts(m, ",uni_xlate");
if (!opts->numtail)
seq_puts(m, ",nonumtail");
if (opts->rodir)
seq_puts(m, ",rodir");
}
if (opts->flush)
seq_puts(m, ",flush");
if (opts->tz_set) {
if (opts->time_offset)
seq_printf(m, ",time_offset=%d", opts->time_offset);
else
seq_puts(m, ",tz=UTC");
}
if (opts->errors == FAT_ERRORS_CONT)
seq_puts(m, ",errors=continue");
else if (opts->errors == FAT_ERRORS_PANIC)
seq_puts(m, ",errors=panic");
else
seq_puts(m, ",errors=remount-ro");
if (opts->nfs == FAT_NFS_NOSTALE_RO)
seq_puts(m, ",nfs=nostale_ro");
else if (opts->nfs)
seq_puts(m, ",nfs=stale_rw");
if (opts->discard)
seq_puts(m, ",discard");
return 0;
}
enum {
Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
Opt_immutable, Opt_dots, Opt_nodots,
Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err,
};
static const match_table_t fat_tokens = {
{Opt_check_r, "check=relaxed"},
{Opt_check_s, "check=strict"},
{Opt_check_n, "check=normal"},
{Opt_check_r, "check=r"},
{Opt_check_s, "check=s"},
{Opt_check_n, "check=n"},
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_umask, "umask=%o"},
{Opt_dmask, "dmask=%o"},
{Opt_fmask, "fmask=%o"},
{Opt_allow_utime, "allow_utime=%o"},
{Opt_codepage, "codepage=%u"},
{Opt_usefree, "usefree"},
{Opt_nocase, "nocase"},
{Opt_quiet, "quiet"},
{Opt_showexec, "showexec"},
{Opt_debug, "debug"},
{Opt_immutable, "sys_immutable"},
{Opt_flush, "flush"},
{Opt_tz_utc, "tz=UTC"},
{Opt_time_offset, "time_offset=%d"},
{Opt_err_cont, "errors=continue"},
{Opt_err_panic, "errors=panic"},
{Opt_err_ro, "errors=remount-ro"},
{Opt_discard, "discard"},
{Opt_nfs_stale_rw, "nfs"},
{Opt_nfs_stale_rw, "nfs=stale_rw"},
{Opt_nfs_nostale_ro, "nfs=nostale_ro"},
{Opt_obsolete, "conv=binary"},
{Opt_obsolete, "conv=text"},
{Opt_obsolete, "conv=auto"},
{Opt_obsolete, "conv=b"},
{Opt_obsolete, "conv=t"},
{Opt_obsolete, "conv=a"},
{Opt_obsolete, "fat=%u"},
{Opt_obsolete, "blocksize=%u"},
{Opt_obsolete, "cvf_format=%20s"},
{Opt_obsolete, "cvf_options=%100s"},
{Opt_obsolete, "posix"},
{Opt_err, NULL},
};
static const match_table_t msdos_tokens = {
{Opt_nodots, "nodots"},
{Opt_nodots, "dotsOK=no"},
{Opt_dots, "dots"},
{Opt_dots, "dotsOK=yes"},
{Opt_err, NULL}
};
static const match_table_t vfat_tokens = {
{Opt_charset, "iocharset=%s"},
{Opt_shortname_lower, "shortname=lower"},
{Opt_shortname_win95, "shortname=win95"},
{Opt_shortname_winnt, "shortname=winnt"},
{Opt_shortname_mixed, "shortname=mixed"},
{Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
{Opt_utf8_no, "utf8=no"},
{Opt_utf8_no, "utf8=false"},
{Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
{Opt_utf8_yes, "utf8=yes"},
{Opt_utf8_yes, "utf8=true"},
{Opt_utf8_yes, "utf8"},
{Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
{Opt_uni_xl_no, "uni_xlate=no"},
{Opt_uni_xl_no, "uni_xlate=false"},
{Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
{Opt_uni_xl_yes, "uni_xlate=yes"},
{Opt_uni_xl_yes, "uni_xlate=true"},
{Opt_uni_xl_yes, "uni_xlate"},
{Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
{Opt_nonumtail_no, "nonumtail=no"},
{Opt_nonumtail_no, "nonumtail=false"},
{Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
{Opt_nonumtail_yes, "nonumtail=yes"},
{Opt_nonumtail_yes, "nonumtail=true"},
{Opt_nonumtail_yes, "nonumtail"},
{Opt_rodir, "rodir"},
{Opt_err, NULL}
};
static int parse_options(struct super_block *sb, char *options, int is_vfat,
int silent, int *debug, struct fat_mount_options *opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
char *iocharset;
opts->isvfat = is_vfat;
opts->fs_uid = current_uid();
opts->fs_gid = current_gid();
opts->fs_fmask = opts->fs_dmask = current_umask();
opts->allow_utime = -1;
opts->codepage = fat_default_codepage;
opts->iocharset = fat_default_iocharset;
if (is_vfat) {
opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
opts->rodir = 0;
} else {
opts->shortname = 0;
opts->rodir = 1;
}
opts->name_check = 'n';
opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
opts->utf8 = opts->unicode_xlate = 0;
opts->numtail = 1;
opts->usefree = opts->nocase = 0;
opts->tz_set = 0;
opts->nfs = 0;
opts->errors = FAT_ERRORS_RO;
*debug = 0;
if (!options)
goto out;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, fat_tokens, args);
if (token == Opt_err) {
if (is_vfat)
token = match_token(p, vfat_tokens, args);
else
token = match_token(p, msdos_tokens, args);
}
switch (token) {
case Opt_check_s:
opts->name_check = 's';
break;
case Opt_check_r:
opts->name_check = 'r';
break;
case Opt_check_n:
opts->name_check = 'n';
break;
case Opt_usefree:
opts->usefree = 1;
break;
case Opt_nocase:
if (!is_vfat)
opts->nocase = 1;
else {
/* for backward compatibility */
opts->shortname = VFAT_SFN_DISPLAY_WIN95
| VFAT_SFN_CREATE_WIN95;
}
break;
case Opt_quiet:
opts->quiet = 1;
break;
case Opt_showexec:
opts->showexec = 1;
break;
case Opt_debug:
*debug = 1;
break;
case Opt_immutable:
opts->sys_immutable = 1;
break;
case Opt_uid:
if (match_int(&args[0], &option))
return -EINVAL;
opts->fs_uid = make_kuid(current_user_ns(), option);
if (!uid_valid(opts->fs_uid))
return -EINVAL;
break;
case Opt_gid:
if (match_int(&args[0], &option))
return -EINVAL;
opts->fs_gid = make_kgid(current_user_ns(), option);
if (!gid_valid(opts->fs_gid))
return -EINVAL;
break;
case Opt_umask:
if (match_octal(&args[0], &option))
return -EINVAL;
opts->fs_fmask = opts->fs_dmask = option;
break;
case Opt_dmask:
if (match_octal(&args[0], &option))
return -EINVAL;
opts->fs_dmask = option;
break;
case Opt_fmask:
if (match_octal(&args[0], &option))
return -EINVAL;
opts->fs_fmask = option;
break;
case Opt_allow_utime:
if (match_octal(&args[0], &option))
return -EINVAL;
opts->allow_utime = option & (S_IWGRP | S_IWOTH);
break;
case Opt_codepage:
if (match_int(&args[0], &option))
return -EINVAL;
opts->codepage = option;
break;
case Opt_flush:
opts->flush = 1;
break;
case Opt_time_offset:
if (match_int(&args[0], &option))
return -EINVAL;
if (option < -12 * 60 || option > 12 * 60)
return -EINVAL;
opts->tz_set = 1;
opts->time_offset = option;
break;
case Opt_tz_utc:
opts->tz_set = 1;
opts->time_offset = 0;
break;
case Opt_err_cont:
opts->errors = FAT_ERRORS_CONT;
break;
case Opt_err_panic:
opts->errors = FAT_ERRORS_PANIC;
break;
case Opt_err_ro:
opts->errors = FAT_ERRORS_RO;
break;
case Opt_nfs_stale_rw:
opts->nfs = FAT_NFS_STALE_RW;
break;
case Opt_nfs_nostale_ro:
opts->nfs = FAT_NFS_NOSTALE_RO;
break;
/* msdos specific */
case Opt_dots:
opts->dotsOK = 1;
break;
case Opt_nodots:
opts->dotsOK = 0;
break;
/* vfat specific */
case Opt_charset:
if (opts->iocharset != fat_default_iocharset)
kfree(opts->iocharset);
iocharset = match_strdup(&args[0]);
if (!iocharset)
return -ENOMEM;
opts->iocharset = iocharset;
break;
case Opt_shortname_lower:
opts->shortname = VFAT_SFN_DISPLAY_LOWER
| VFAT_SFN_CREATE_WIN95;
break;
case Opt_shortname_win95:
opts->shortname = VFAT_SFN_DISPLAY_WIN95
| VFAT_SFN_CREATE_WIN95;
break;
case Opt_shortname_winnt:
opts->shortname = VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WINNT;
break;
case Opt_shortname_mixed:
opts->shortname = VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WIN95;
break;
case Opt_utf8_no: /* 0 or no or false */
opts->utf8 = 0;
break;
case Opt_utf8_yes: /* empty or 1 or yes or true */
opts->utf8 = 1;
break;
case Opt_uni_xl_no: /* 0 or no or false */
opts->unicode_xlate = 0;
break;
case Opt_uni_xl_yes: /* empty or 1 or yes or true */
opts->unicode_xlate = 1;
break;
case Opt_nonumtail_no: /* 0 or no or false */
opts->numtail = 1; /* negated option */
break;
case Opt_nonumtail_yes: /* empty or 1 or yes or true */
opts->numtail = 0; /* negated option */
break;
case Opt_rodir:
opts->rodir = 1;
break;
case Opt_discard:
opts->discard = 1;
break;
/* obsolete mount options */
case Opt_obsolete:
fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
"not supported now", p);
break;
/* unknown option */
default:
if (!silent) {
fat_msg(sb, KERN_ERR,
"Unrecognized mount option \"%s\" "
"or missing value", p);
}
return -EINVAL;
}
}
out:
/* UTF-8 doesn't provide FAT semantics */
if (!strcmp(opts->iocharset, "utf8")) {
fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
" for FAT filesystems, filesystem will be "
"case sensitive!");
}
/* If user doesn't specify allow_utime, it's initialized from dmask. */
if (opts->allow_utime == (unsigned short)-1)
opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
if (opts->unicode_xlate)
opts->utf8 = 0;
if (opts->nfs == FAT_NFS_NOSTALE_RO)
sb->s_flags |= MS_RDONLY;
return 0;
}
static int fat_read_root(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
int error;
MSDOS_I(inode)->i_pos = 0;
inode->i_uid = sbi->options.fs_uid;
inode->i_gid = sbi->options.fs_gid;
inode->i_version++;
inode->i_generation = 0;
inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
inode->i_op = sbi->dir_ops;
inode->i_fop = &fat_dir_operations;
if (sbi->fat_bits == 32) {
MSDOS_I(inode)->i_start = sbi->root_cluster;
error = fat_calc_dir_size(inode);
if (error < 0)
return error;
} else {
MSDOS_I(inode)->i_start = 0;
inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
}
inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
& ~((loff_t)sbi->cluster_size - 1)) >> 9;
MSDOS_I(inode)->i_logstart = 0;
MSDOS_I(inode)->mmu_private = inode->i_size;
fat_save_attrs(inode, ATTR_DIR);
inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
set_nlink(inode, fat_subdirs(inode)+2);
return 0;
}
/*
* Read the super block of an MS-DOS FS.
*/
int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
void (*setup)(struct super_block *))
{
struct inode *root_inode = NULL, *fat_inode = NULL;
struct inode *fsinfo_inode = NULL;
struct buffer_head *bh;
struct fat_boot_sector *b;
struct msdos_sb_info *sbi;
u16 logical_sector_size;
u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
int debug;
unsigned int media;
long error;
char buf[50];
/*
* GFP_KERNEL is ok here, because while we do hold the
* supeblock lock, memory pressure can't call back into
* the filesystem, since we're only just about to mount
* it and have no inodes etc active!
*/
sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
sb->s_flags |= MS_NODIRATIME;
sb->s_magic = MSDOS_SUPER_MAGIC;
sb->s_op = &fat_sops;
sb->s_export_op = &fat_export_ops;
ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
if (error)
goto out_fail;
setup(sb); /* flavour-specific stuff that needs options */
error = -EIO;
sb_min_blocksize(sb, 512);
bh = sb_bread(sb, 0);
if (bh == NULL) {
fat_msg(sb, KERN_ERR, "unable to read boot sector");
goto out_fail;
}
b = (struct fat_boot_sector *) bh->b_data;
if (!b->reserved) {
if (!silent)
fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
brelse(bh);
goto out_invalid;
}
if (!b->fats) {
if (!silent)
fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
brelse(bh);
goto out_invalid;
}
/*
* Earlier we checked here that b->secs_track and b->head are nonzero,
* but it turns out valid FAT filesystems can have zero there.
*/
media = b->media;
if (!fat_valid_media(media)) {
if (!silent)
fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
media);
brelse(bh);
goto out_invalid;
}
logical_sector_size = get_unaligned_le16(&b->sector_size);
if (!is_power_of_2(logical_sector_size)
|| (logical_sector_size < 512)
|| (logical_sector_size > 4096)) {
if (!silent)
fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
logical_sector_size);
brelse(bh);
goto out_invalid;
}
sbi->sec_per_clus = b->sec_per_clus;
if (!is_power_of_2(sbi->sec_per_clus)) {
if (!silent)
fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
sbi->sec_per_clus);
brelse(bh);
goto out_invalid;
}
if (logical_sector_size < sb->s_blocksize) {
fat_msg(sb, KERN_ERR, "logical sector size too small for device"
" (logical sector size = %u)", logical_sector_size);
brelse(bh);
goto out_fail;
}
if (logical_sector_size > sb->s_blocksize) {
brelse(bh);
if (!sb_set_blocksize(sb, logical_sector_size)) {
fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
logical_sector_size);
goto out_fail;
}
bh = sb_bread(sb, 0);
if (bh == NULL) {
fat_msg(sb, KERN_ERR, "unable to read boot sector"
" (logical sector size = %lu)",
sb->s_blocksize);
goto out_fail;
}
b = (struct fat_boot_sector *) bh->b_data;
}
mutex_init(&sbi->s_lock);
sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
sbi->fats = b->fats;
sbi->fat_bits = 0; /* Don't know yet */
sbi->fat_start = le16_to_cpu(b->reserved);
sbi->fat_length = le16_to_cpu(b->fat_length);
sbi->root_cluster = 0;
sbi->free_clusters = -1; /* Don't know yet */
sbi->free_clus_valid = 0;
sbi->prev_free = FAT_START_ENT;
sb->s_maxbytes = 0xffffffff;
if (!sbi->fat_length && b->fat32.length) {
struct fat_boot_fsinfo *fsinfo;
struct buffer_head *fsinfo_bh;
/* Must be FAT32 */
sbi->fat_bits = 32;
sbi->fat_length = le32_to_cpu(b->fat32.length);
sbi->root_cluster = le32_to_cpu(b->fat32.root_cluster);
/* MC - if info_sector is 0, don't multiply by 0 */
sbi->fsinfo_sector = le16_to_cpu(b->fat32.info_sector);
if (sbi->fsinfo_sector == 0)
sbi->fsinfo_sector = 1;
fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
if (fsinfo_bh == NULL) {
fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
" (sector = %lu)", sbi->fsinfo_sector);
brelse(bh);
goto out_fail;
}
fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
if (!IS_FSINFO(fsinfo)) {
fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
"0x%08x, 0x%08x (sector = %lu)",
le32_to_cpu(fsinfo->signature1),
le32_to_cpu(fsinfo->signature2),
sbi->fsinfo_sector);
} else {
if (sbi->options.usefree)
sbi->free_clus_valid = 1;
sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
}
brelse(fsinfo_bh);
}
sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
if (!silent)
fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
" (%u)", sbi->dir_entries);
brelse(bh);
goto out_invalid;
}
rootdir_sectors = sbi->dir_entries
* sizeof(struct msdos_dir_entry) / sb->s_blocksize;
sbi->data_start = sbi->dir_start + rootdir_sectors;
total_sectors = get_unaligned_le16(&b->sectors);
if (total_sectors == 0)
total_sectors = le32_to_cpu(b->total_sect);
total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
if (sbi->fat_bits != 32)
sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
/* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
if (sbi->fat_bits == 32)
sbi->dirty = b->fat32.state & FAT_STATE_DIRTY;
else /* fat 16 or 12 */
sbi->dirty = b->fat16.state & FAT_STATE_DIRTY;
/* check that FAT table does not overflow */
fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
if (total_clusters > MAX_FAT(sb)) {
if (!silent)
fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
total_clusters);
brelse(bh);
goto out_invalid;
}
sbi->max_cluster = total_clusters + FAT_START_ENT;
/* check the free_clusters, it's not necessarily correct */
if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
sbi->free_clusters = -1;
/* check the prev_free, it's not necessarily correct */
sbi->prev_free %= sbi->max_cluster;
if (sbi->prev_free < FAT_START_ENT)
sbi->prev_free = FAT_START_ENT;
brelse(bh);
/* set up enough so that it can read an inode */
fat_hash_init(sb);
dir_hash_init(sb);
fat_ent_access_init(sb);
/*
* The low byte of FAT's first entry must have same value with
* media-field. But in real world, too many devices is
* writing wrong value. So, removed that validity check.
*
* if (FAT_FIRST_ENT(sb, media) != first)
*/
error = -EINVAL;
sprintf(buf, "cp%d", sbi->options.codepage);
sbi->nls_disk = load_nls(buf);
if (!sbi->nls_disk) {
fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
goto out_fail;
}
/* FIXME: utf8 is using iocharset for upper/lower conversion */
if (sbi->options.isvfat) {
sbi->nls_io = load_nls(sbi->options.iocharset);
if (!sbi->nls_io) {
fat_msg(sb, KERN_ERR, "IO charset %s not found",
sbi->options.iocharset);
goto out_fail;
}
}
error = -ENOMEM;
fat_inode = new_inode(sb);
if (!fat_inode)
goto out_fail;
MSDOS_I(fat_inode)->i_pos = 0;
sbi->fat_inode = fat_inode;
fsinfo_inode = new_inode(sb);
if (!fsinfo_inode)
goto out_fail;
fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
sbi->fsinfo_inode = fsinfo_inode;
insert_inode_hash(fsinfo_inode);
root_inode = new_inode(sb);
if (!root_inode)
goto out_fail;
root_inode->i_ino = MSDOS_ROOT_INO;
root_inode->i_version = 1;
error = fat_read_root(root_inode);
if (error < 0) {
iput(root_inode);
goto out_fail;
}
error = -ENOMEM;
insert_inode_hash(root_inode);
fat_attach(root_inode, 0);
sb->s_root = d_make_root(root_inode);
if (!sb->s_root) {
fat_msg(sb, KERN_ERR, "get root inode failed");
goto out_fail;
}
if (sbi->options.discard) {
struct request_queue *q = bdev_get_queue(sb->s_bdev);
if (!blk_queue_discard(q))
fat_msg(sb, KERN_WARNING,
"mounting with \"discard\" option, but "
"the device does not support discard");
}
fat_set_state(sb, 1, 0);
return 0;
out_invalid:
error = -EINVAL;
if (!silent)
fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
out_fail:
if (fsinfo_inode)
iput(fsinfo_inode);
if (fat_inode)
iput(fat_inode);
unload_nls(sbi->nls_io);
unload_nls(sbi->nls_disk);
if (sbi->options.iocharset != fat_default_iocharset)
kfree(sbi->options.iocharset);
sb->s_fs_info = NULL;
kfree(sbi);
return error;
}
EXPORT_SYMBOL_GPL(fat_fill_super);
/*
* helper function for fat_flush_inodes. This writes both the inode
* and the file data blocks, waiting for in flight data blocks before
* the start of the call. It does not wait for any io started
* during the call
*/
static int writeback_inode(struct inode *inode)
{
int ret;
/* if we used wait=1, sync_inode_metadata waits for the io for the
* inode to finish. So wait=0 is sent down to sync_inode_metadata
* and filemap_fdatawrite is used for the data blocks
*/
ret = sync_inode_metadata(inode, 0);
if (!ret)
ret = filemap_fdatawrite(inode->i_mapping);
return ret;
}
/*
* write data and metadata corresponding to i1 and i2. The io is
* started but we do not wait for any of it to finish.
*
* filemap_flush is used for the block device, so if there is a dirty
* page for a block already in flight, we will not wait and start the
* io over again
*/
int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
{
int ret = 0;
if (!MSDOS_SB(sb)->options.flush)
return 0;
if (i1)
ret = writeback_inode(i1);
if (!ret && i2)
ret = writeback_inode(i2);
if (!ret) {
struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
ret = filemap_flush(mapping);
}
return ret;
}
EXPORT_SYMBOL_GPL(fat_flush_inodes);
static int __init init_fat_fs(void)
{
int err;
err = fat_cache_init();
if (err)
return err;
err = fat_init_inodecache();
if (err)
goto failed;
return 0;
failed:
fat_cache_destroy();
return err;
}
static void __exit exit_fat_fs(void)
{
fat_cache_destroy();
fat_destroy_inodecache();
}
module_init(init_fat_fs)
module_exit(exit_fat_fs)
MODULE_LICENSE("GPL");