Commit 85c78591 authored by Denis Karpov's avatar Denis Karpov Committed by OGAWA Hirofumi

FAT: add 'errors' mount option

On severe errors FAT remounts itself in read-only mode. Allow to
specify FAT fs desired behavior through 'errors' mount option:
panic, continue or remount read-only.

`mount -t [fat|vfat] -o errors=[panic,remount-ro,continue] \
	<bdev> <mount point>`

This is analog to ext2 fs 'errors' mount option.
Signed-off-by: default avatarDenis Karpov <ext-denis.2.karpov@nokia.com>
Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
parent 9fa7eb28
......@@ -132,6 +132,11 @@ rodir -- FAT has the ATTR_RO (read-only) attribute. But on Windows,
If you want to use ATTR_RO as read-only flag even for
the directory, set this option.
errors=panic|continue|remount-ro
-- specify FAT behavior on critical errors: panic, continue
without doing anything or remount the partition in
read-only mode (default behavior).
<bool>: 0,1,yes,no,true,false
TODO
......
......@@ -241,7 +241,7 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
while (*fclus < cluster) {
/* prevent the infinite loop of cluster chain */
if (*fclus > limit) {
fat_fs_panic(sb, "%s: detected the cluster chain loop"
fat_fs_error(sb, "%s: detected the cluster chain loop"
" (i_pos %lld)", __func__,
MSDOS_I(inode)->i_pos);
nr = -EIO;
......@@ -252,7 +252,7 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
if (nr < 0)
goto out;
else if (nr == FAT_ENT_FREE) {
fat_fs_panic(sb, "%s: invalid cluster chain"
fat_fs_error(sb, "%s: invalid cluster chain"
" (i_pos %lld)", __func__,
MSDOS_I(inode)->i_pos);
nr = -EIO;
......@@ -285,7 +285,7 @@ static int fat_bmap_cluster(struct inode *inode, int cluster)
if (ret < 0)
return ret;
else if (ret == FAT_ENT_EOF) {
fat_fs_panic(sb, "%s: request beyond EOF (i_pos %lld)",
fat_fs_error(sb, "%s: request beyond EOF (i_pos %lld)",
__func__, MSDOS_I(inode)->i_pos);
return -EIO;
}
......
......@@ -1334,7 +1334,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
goto error_remove;
}
if (dir->i_size & (sbi->cluster_size - 1)) {
fat_fs_panic(sb, "Odd directory size");
fat_fs_error(sb, "Odd directory size");
dir->i_size = (dir->i_size + sbi->cluster_size - 1)
& ~((loff_t)sbi->cluster_size - 1);
}
......
......@@ -17,6 +17,10 @@
#define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
#define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
#define FAT_ERRORS_CONT 1 /* ignore error and continue */
#define FAT_ERRORS_PANIC 2 /* panic on error */
#define FAT_ERRORS_RO 3 /* remount r/o on error */
struct fat_mount_options {
uid_t fs_uid;
gid_t fs_gid;
......@@ -26,6 +30,7 @@ struct fat_mount_options {
char *iocharset; /* Charset used for filename input/display */
unsigned short shortname; /* flags for shortname display/create rule */
unsigned char name_check; /* r = relaxed, n = normal, s = strict */
unsigned char errors; /* On error: continue, panic, remount-ro */
unsigned short allow_utime;/* permission for setting the [am]time */
unsigned quiet:1, /* set = fake successful chmods and chowns */
showexec:1, /* set = only set x bit for com/exe/bat */
......@@ -310,7 +315,7 @@ extern int fat_fill_super(struct super_block *sb, void *data, int silent,
extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
struct inode *i2);
/* fat/misc.c */
extern void fat_fs_panic(struct super_block *s, const char *fmt, ...)
extern void fat_fs_error(struct super_block *s, const char *fmt, ...)
__attribute__ ((format (printf, 2, 3))) __cold;
extern void fat_clusters_flush(struct super_block *sb);
extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
......
......@@ -345,7 +345,7 @@ int fat_ent_read(struct inode *inode, struct fat_entry *fatent, int entry)
if (entry < FAT_START_ENT || sbi->max_cluster <= entry) {
fatent_brelse(fatent);
fat_fs_panic(sb, "invalid access to FAT (entry 0x%08x)", entry);
fat_fs_error(sb, "invalid access to FAT (entry 0x%08x)", entry);
return -EIO;
}
......@@ -557,7 +557,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
err = cluster;
goto error;
} else if (cluster == FAT_ENT_FREE) {
fat_fs_panic(sb, "%s: deleting FAT entry beyond EOF",
fat_fs_error(sb, "%s: deleting FAT entry beyond EOF",
__func__);
err = -EIO;
goto error;
......
......@@ -213,7 +213,7 @@ static int fat_free(struct inode *inode, int skip)
fatent_brelse(&fatent);
return 0;
} else if (ret == FAT_ENT_FREE) {
fat_fs_panic(sb,
fat_fs_error(sb,
"%s: invalid cluster chain (i_pos %lld)",
__func__, MSDOS_I(inode)->i_pos);
ret = -EIO;
......
......@@ -76,7 +76,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
return 0;
if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
return -EIO;
}
......@@ -834,6 +834,12 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
seq_puts(m, ",flush");
if (opts->tz_utc)
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");
return 0;
}
......@@ -846,7 +852,8 @@ enum {
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_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err,
Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
Opt_err_panic, Opt_err_ro, Opt_err,
};
static const match_table_t fat_tokens = {
......@@ -869,6 +876,11 @@ static const match_table_t fat_tokens = {
{Opt_showexec, "showexec"},
{Opt_debug, "debug"},
{Opt_immutable, "sys_immutable"},
{Opt_flush, "flush"},
{Opt_tz_utc, "tz=UTC"},
{Opt_err_cont, "errors=continue"},
{Opt_err_panic, "errors=panic"},
{Opt_err_ro, "errors=remount-ro"},
{Opt_obsolate, "conv=binary"},
{Opt_obsolate, "conv=text"},
{Opt_obsolate, "conv=auto"},
......@@ -880,8 +892,6 @@ static const match_table_t fat_tokens = {
{Opt_obsolate, "cvf_format=%20s"},
{Opt_obsolate, "cvf_options=%100s"},
{Opt_obsolate, "posix"},
{Opt_flush, "flush"},
{Opt_tz_utc, "tz=UTC"},
{Opt_err, NULL},
};
static const match_table_t msdos_tokens = {
......@@ -951,6 +961,7 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
opts->numtail = 1;
opts->usefree = opts->nocase = 0;
opts->tz_utc = 0;
opts->errors = FAT_ERRORS_RO;
*debug = 0;
if (!options)
......@@ -1043,6 +1054,15 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
case Opt_tz_utc:
opts->tz_utc = 1;
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;
/* msdos specific */
case Opt_dots:
......
......@@ -12,14 +12,19 @@
#include "fat.h"
/*
* fat_fs_panic reports a severe file system problem and sets the file system
* read-only. The file system can be made writable again by remounting it.
* fat_fs_error reports a file system problem that might indicate fa data
* corruption/inconsistency. Depending on 'errors' mount option the
* panic() is called, or error message is printed FAT and nothing is done,
* or filesystem is remounted read-only (default behavior).
* In case the file system is remounted read-only, it can be made writable
* again by remounting it.
*/
void fat_fs_panic(struct super_block *s, const char *fmt, ...)
void fat_fs_error(struct super_block *s, const char *fmt, ...)
{
struct fat_mount_options *opts = &MSDOS_SB(s)->options;
va_list args;
printk(KERN_ERR "FAT: Filesystem panic (dev %s)\n", s->s_id);
printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);
printk(KERN_ERR " ");
va_start(args, fmt);
......@@ -27,13 +32,14 @@ void fat_fs_panic(struct super_block *s, const char *fmt, ...)
va_end(args);
printk("\n");
if (!(s->s_flags & MS_RDONLY)) {
if (opts->errors == FAT_ERRORS_PANIC)
panic(" FAT fs panic from previous error\n");
else if (opts->errors == FAT_ERRORS_RO && !(s->s_flags & MS_RDONLY)) {
s->s_flags |= MS_RDONLY;
printk(KERN_ERR " File system has been set read-only\n");
}
}
EXPORT_SYMBOL_GPL(fat_fs_panic);
EXPORT_SYMBOL_GPL(fat_fs_error);
/* Flushes the number of free clusters on FAT32 */
/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
......@@ -124,7 +130,7 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
mark_inode_dirty(inode);
}
if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
fat_fs_panic(sb, "clusters badly computed (%d != %llu)",
fat_fs_error(sb, "clusters badly computed (%d != %llu)",
new_fclus,
(llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
fat_cache_inval_inode(inode);
......
......@@ -608,7 +608,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
sinfo.bh = NULL;
}
if (corrupt < 0) {
fat_fs_panic(new_dir->i_sb,
fat_fs_error(new_dir->i_sb,
"%s: Filesystem corrupted (i_pos %lld)",
__func__, sinfo.i_pos);
}
......
......@@ -1030,7 +1030,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
sinfo.bh = NULL;
}
if (corrupt < 0) {
fat_fs_panic(new_dir->i_sb,
fat_fs_error(new_dir->i_sb,
"%s: Filesystem corrupted (i_pos %lld)",
__func__, sinfo.i_pos);
}
......
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