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: Denis Karpov <ext-denis.2.karpov@nokia.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
diff --git a/fs/fat/cache.c b/fs/fat/cache.c
index b426022..923990e 100644
--- a/fs/fat/cache.c
+++ b/fs/fat/cache.c
@@ -241,7 +241,7 @@
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 @@
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 @@
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;
}
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 3a7f603..7e7924c 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -1334,7 +1334,7 @@
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);
}
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index ea440d6..ed10896 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -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 @@
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_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);
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index da6eea4..60c31f7 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -345,7 +345,7 @@
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 @@
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;
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 0a7f4a9..6214287 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -213,7 +213,7 @@
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;
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 296785a..2b90522 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -76,7 +76,7 @@
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 @@
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 @@
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 @@
{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 @@
{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 @@
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 @@
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:
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index ac39ebc..a6c2047 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -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 @@
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 @@
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);
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index da3f361..72f5c64 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -608,7 +608,7 @@
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);
}
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index a0e00e3..cb6ddb8 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -1030,7 +1030,7 @@
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);
}