Add mechnism to optionally notify userspace about fs errors with
uevents associated with fs kobject's attribute:
/sys/fs/fat/<part_bdev>/fs_fault
uevent's type is KOBJ_CHANGE, uevent's environment variable FS_FAULT=1.
Signed-off-by: Denis Karpov <ext-denis.2.karpov@xxxxxxxxx>
---
fs/fat/fat.h | 6 +++---
fs/fat/inode.c | 37 +++++++++++++++++++++++++++++++------
fs/fat/misc.c | 4 ++--
3 files changed, 36 insertions(+), 11 deletions(-)
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 480be11..ebf4c62 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -87,9 +87,9 @@ struct msdos_sb_info {
#define FAT_CACHE_VALID 0 /* special case for valid cache */
/* Mark FAT run-time errors */
-#define FAT_FS_FAULT_SET(sbi, val) \
+#define FAT_FS_FAULT_SET(sbi, val, notify) \
fat_sbi_attr_set_notify(sbi, offsetof(struct msdos_sb_info, fs_fault), \
- val)
+ val, notify)
/*
* MS-DOS file system inode data in memory
@@ -320,7 +320,7 @@ 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);
extern int fat_sbi_attr_set_notify(struct msdos_sb_info *sbi,
- unsigned long offset, unsigned long val);
+ unsigned long offset, unsigned long val, int notify);
/* fat/misc.c */
extern void fat_fs_error(struct super_block *s, const char *function,
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 4613343..b1a0c8d 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -527,7 +527,7 @@ static int fat_remount(struct super_block *sb, int *flags, char *data)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
*flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
- FAT_FS_FAULT_SET(sbi, 0);
+ FAT_FS_FAULT_SET(sbi, 0, 0);
return 0;
}
@@ -1185,6 +1185,7 @@ struct fat_attr {
ssize_t (*store)(struct fat_attr *, struct msdos_sb_info *,
const char *, size_t);
unsigned short offset;
+ unsigned short uevent;
};
static ssize_t fat_sbi_attr_show(struct fat_attr *a, struct msdos_sb_info *sbi,
@@ -1206,17 +1207,22 @@ static ssize_t fat_sbi_attr_store(struct fat_attr *a,
return count;
}
-#define FAT_SBI_ATTR(_name, _mode, _show, _store) \
+#define FAT_SBI_ATTR(_name, _mode, _show, _store, _uevent) \
static struct fat_attr fat_attr_##_name = { \
.attr = {.name = __stringify(_name), .mode = _mode }, \
.show = _show, \
.store = _store, \
.offset = offsetof(struct msdos_sb_info, _name), \
+ .uevent = _uevent, \
}
#define FAT_SBI_RO_ATTR(name) FAT_SBI_ATTR(name, 0444, \
- fat_sbi_attr_show, NULL)
+ fat_sbi_attr_show, NULL, 0)
#define FAT_SBI_RW_ATTR(name) FAT_SBI_ATTR(name, 0644 \
- fat_sbi_attr_show, fat_sbi_attr_store)
+ fat_sbi_attr_show, fat_sbi_attr_store, 0)
+#define FAT_SBI_RO_ATTR_NOTIFY(name) FAT_SBI_ATTR(name, 0444, \
+ fat_sbi_attr_show, NULL, 1)
+#define FAT_SBI_RW_ATTR_NOTIFY(name) FAT_SBI_ATTR(name, 0644, \
+ fat_sbi_attr_show, fat_sbi_attr_store, 1)
#define ATTR_LIST(name) (&fat_attr_ ##name.attr)
@@ -1240,11 +1246,15 @@ static struct attribute *find_attr_by_offset(struct kobject *kobj,
int fat_sbi_attr_set_notify(struct msdos_sb_info *sbi,
unsigned long offset,
- unsigned long val)
+ unsigned long val,
+ int notify)
{
struct fat_attr *a =
(struct fat_attr *) find_attr_by_offset(&sbi->s_kobj, offset);
unsigned long *attr_val;
+ int ev_len;
+ char *t_str;
+ char *envp[] = { NULL, NULL };
if (!a)
return -EINVAL;
@@ -1257,6 +1267,21 @@ int fat_sbi_attr_set_notify(struct msdos_sb_info *sbi,
sysfs_notify(&sbi->s_kobj, NULL, a->attr.name);
+ if (!notify || !a->uevent)
+ return 0;
+
+ /* dec MAX_UINT == 10 char string */
+ ev_len = strlen(a->attr.name) + 1 + 10 + 1;
+ envp[0] = t_str = kzalloc(ev_len, GFP_KERNEL);
+ if (!t_str)
+ return -ENOMEM;
+
+ snprintf(t_str, ev_len, "%s=%lu", a->attr.name, val);
+ while ((*t_str++ = toupper(*t_str)))
+ ;
+ kobject_uevent_env(&sbi->s_kobj, KOBJ_CHANGE, envp);
+ kfree(envp[0]);
+
return 0;
}
EXPORT_SYMBOL(fat_sbi_attr_set_notify);
@@ -1573,7 +1598,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
printk(KERN_ERR "FAT: create fs kobject failed\n");
goto out_fail;
}
- FAT_FS_FAULT_SET(sbi, 0);
+ FAT_FS_FAULT_SET(sbi, 0, 0);
return 0;
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index ce478be..8cdefd8 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -35,7 +35,7 @@ void fat_fs_error(struct super_block *s, const char *function,
printk(KERN_ERR " File system has been set read-only\n");
}
- FAT_FS_FAULT_SET(sbi, 1);
+ FAT_FS_FAULT_SET(sbi, 1, 0);
}
EXPORT_SYMBOL_GPL(fat_fs_error);
@@ -58,7 +58,7 @@ void fat_fs_warning(struct super_block *s, const char * function,
printk("\n");
va_end(args);
- FAT_FS_FAULT_SET(sbi, 1);
+ FAT_FS_FAULT_SET(sbi, 1, 0);
}
EXPORT_SYMBOL_GPL(fat_fs_warning);
--
1.6.3.1
--
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