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authorEric Sandeen <sandeen@redhat.com>2009-08-17 23:48:51 -0400
committerTheodore Ts'o <tytso@mit.edu>2009-08-17 23:48:51 -0400
commitbf43d84b185e2ff54598f8c58a5a8e63148b6e90 (patch)
tree1e7a7ca7e5d328c41ef6757ea33d709d8e47fcfb
parent0ccff1a49def92d6b838a6da166c89004b3a4d0c (diff)
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>
-rw-r--r--fs/ext4/super.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index fe3f376b7df..de67c3657b8 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;
}