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| author |   Arnd Bergmann <arnd@arndb.de> | 2018-07-29 15:48:00 -0400 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2018-07-29 15:48:00 -0400 |
| commit | a4d2aadca184ece182418950d45ba4ffc7b652d2 (patch) | |
| tree | b37122c211f28e99dabff87b1dd0d8f998b98d6d /fs/ext4 | |
| parent | ext4: import extended attributes chapter from wiki page (diff) | |
| download | linux-dev-a4d2aadca184ece182418950d45ba4ffc7b652d2.tar.xz linux-dev-a4d2aadca184ece182418950d45ba4ffc7b652d2.zip | |
ext4: sysfs: print ext4_super_block fields as little-endian
While working on extended rand for last_error/first_error timestamps,
I noticed that the endianess is wrong; we access the little-endian
fields in struct ext4_super_block as native-endian when we print them.
This adds a special case in ext4_attr_show() and ext4_attr_store()
to byteswap the superblock fields if needed.
In older kernels, this code was part of super.c, it got moved to
sysfs.c in linux-4.4.
Cc: stable@vger.kernel.org
Fixes: 52c198c6820f ("ext4: add sysfs entry showing whether the fs contains errors")
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/sysfs.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index f34da0bb8f17..b970a200f20c 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -274,8 +274,12 @@ static ssize_t ext4_attr_show(struct kobject *kobj, case attr_pointer_ui: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%u\n", - *((unsigned int *) ptr)); + if (a->attr_ptr == ptr_ext4_super_block_offset) + return snprintf(buf, PAGE_SIZE, "%u\n", + le32_to_cpup(ptr)); + else + return snprintf(buf, PAGE_SIZE, "%u\n", + *((unsigned int *) ptr)); case attr_pointer_atomic: if (!ptr) return 0; @@ -308,7 +312,10 @@ static ssize_t ext4_attr_store(struct kobject *kobj, ret = kstrtoul(skip_spaces(buf), 0, &t); if (ret) return ret; - *((unsigned int *) ptr) = t; + if (a->attr_ptr == ptr_ext4_super_block_offset) + *((__le32 *) ptr) = cpu_to_le32(t); + else + *((unsigned int *) ptr) = t; return len; case attr_inode_readahead: return inode_readahead_blks_store(sbi, buf, len); |