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| author | Arnd Bergmann <arnd@arndb.de> | 2018-07-29 15:48:00 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-05 09:18:38 +0200 |
| commit | bca4f76edcc74a0290fd007bf937217a8c43ee00 (patch) | |
| tree | 2c054bd1d039ad875aea855388e056a318212c87 | |
| parent | ac92782e4ef6fc9f4694bdc9e1b5d5bfb72027ff (diff) | |
| download | linux-cip-bca4f76edcc74a0290fd007bf937217a8c43ee00.tar.gz | |
ext4: sysfs: print ext4_super_block fields as little-endian
commit a4d2aadca184ece182418950d45ba4ffc7b652d2 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 c2ee23acf35947..ae9929d678d6f6 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -277,8 +277,12 @@ 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; @@ -311,7 +315,10 @@ 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(a, sbi, buf, len); |