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| author | Eric Sandeen <sandeen@redhat.com> | 2009-08-17 23:48:51 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-08-17 23:48:51 -0400 |
| commit | bf43d84b185e2ff54598f8c58a5a8e63148b6e90 (patch) | |
| tree | 1e7a7ca7e5d328c41ef6757ea33d709d8e47fcfb /fs/ext4/super.c | |
| parent | 0ccff1a49def92d6b838a6da166c89004b3a4d0c (diff) | |
| download | linux-bf43d84b185e2ff54598f8c58a5a8e63148b6e90.tar.bz2 | |
ext4: reject too-large filesystems on 32-bit kernels
ext4 will happily mount a > 16T filesystem on a 32-bit box, but
this is not safe; writes to the block device will wrap past 16T
and the page cache can't index past 16T (232 index * 4k pages).
Adding another test to the existing "too many sectors" test
should do the trick.
Add a comment, a relevant return value, and fix the reference
to the CONFIG_LBD(AF) option as well.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index fe3f376b7df2..de67c3657b83 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2550,12 +2550,19 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) goto failed_mount; } - if (ext4_blocks_count(es) > - (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { + /* + * Test whether we have more sectors than will fit in sector_t, + * and whether the max offset is addressable by the page cache. + */ + if ((ext4_blocks_count(es) > + (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) || + (ext4_blocks_count(es) > + (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits))) { ext4_msg(sb, KERN_ERR, "filesystem" - " too large to mount safely"); + " too large to mount safely on this system"); if (sizeof(sector_t) < 8) ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled"); + ret = -EFBIG; goto failed_mount; } |