From b9f95911e9e89a456c9b7bdc0ca68c111a931b30 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sat, 2 Aug 2014 22:49:12 -0400 Subject: [PATCH] libext2fs: don't cache inodes that fail checksum verification If an inode fails checksum verification, don't stuff a copy of it in the inode cache, because this can cause the library to fail to return the "corrupt inode" error code. In general, this happens if ext2fs_read_inode_full() is called twice on an inode with an incorrect checksum. If fs->flags has EXT2_FLAG_IGNORE_CSUM_ERRORS set during the first call and *unset* during the second call, the cache hit during the second call fails to return EXT2_ET_INODE_CSUM_INVALID as you'd expect. This happens during fsck because the first read_inode call happens as part of check_blocks and the second call happens during inode checksum revalidation. A file system with a slightly corrupt non-extent inode will trigger this. While we're at it, make the inode read function consistent with the rest of libext2fs -- copy the metadata object into the caller's buffer even if it fails checksum verification. This will help e2fsck avoid a double re-read later on down the line. Signed-off-by: Darrick J. Wong Signed-off-by: Theodore Ts'o --- lib/ext2fs/inode.c | 15 +++++++++------ tests/f_no_cache_corrupt_inode/expect.1 | 11 +++++++++++ tests/f_no_cache_corrupt_inode/expect.2 | 7 +++++++ tests/f_no_cache_corrupt_inode/image.gz | Bin 0 -> 2606 bytes tests/f_no_cache_corrupt_inode/name | 1 + 5 files changed, 28 insertions(+), 6 deletions(-) create mode 100644 tests/f_no_cache_corrupt_inode/expect.1 create mode 100644 tests/f_no_cache_corrupt_inode/expect.2 create mode 100644 tests/f_no_cache_corrupt_inode/image.gz create mode 100644 tests/f_no_cache_corrupt_inode/name diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c index a6213aed..6c766af5 100644 --- a/lib/ext2fs/inode.c +++ b/lib/ext2fs/inode.c @@ -709,7 +709,7 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, io_channel io; int length = EXT2_INODE_SIZE(fs->super); struct ext2_inode_large *iptr; - int cache_slot; + int cache_slot, fail_csum; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); @@ -787,9 +787,7 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, length = EXT2_INODE_SIZE(fs->super); /* Verify the inode checksum. */ - if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && - !ext2fs_inode_csum_verify(fs, ino, iptr)) - return EXT2_ET_INODE_CSUM_INVALID; + fail_csum = !ext2fs_inode_csum_verify(fs, ino, iptr); #ifdef WORDS_BIGENDIAN ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr, @@ -798,10 +796,15 @@ errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, #endif /* Update the inode cache bookkeeping */ - fs->icache->cache_last = cache_slot; - fs->icache->cache[cache_slot].ino = ino; + if (!fail_csum) { + fs->icache->cache_last = cache_slot; + fs->icache->cache[cache_slot].ino = ino; + } memcpy(inode, iptr, (bufsize > length) ? length : bufsize); + if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && fail_csum) + return EXT2_ET_INODE_CSUM_INVALID; + return 0; } diff --git a/tests/f_no_cache_corrupt_inode/expect.1 b/tests/f_no_cache_corrupt_inode/expect.1 new file mode 100644 index 00000000..4f82f757 --- /dev/null +++ b/tests/f_no_cache_corrupt_inode/expect.1 @@ -0,0 +1,11 @@ +Pass 1: Checking inodes, blocks, and sizes +Inode 12 passes checks, but checksum does not match inode. Fix? yes + +Pass 2: Checking directory structure +Pass 3: Checking directory connectivity +Pass 4: Checking reference counts +Pass 5: Checking group summary information + +test_filesys: ***** FILE SYSTEM WAS MODIFIED ***** +test_filesys: 12/128 files (0.0% non-contiguous), 19/512 blocks +Exit status is 1 diff --git a/tests/f_no_cache_corrupt_inode/expect.2 b/tests/f_no_cache_corrupt_inode/expect.2 new file mode 100644 index 00000000..1b43315f --- /dev/null +++ b/tests/f_no_cache_corrupt_inode/expect.2 @@ -0,0 +1,7 @@ +Pass 1: Checking inodes, blocks, and sizes +Pass 2: Checking directory structure +Pass 3: Checking directory connectivity +Pass 4: Checking reference counts +Pass 5: Checking group summary information +test_filesys: 12/128 files (0.0% non-contiguous), 19/512 blocks +Exit status is 0 diff --git a/tests/f_no_cache_corrupt_inode/image.gz b/tests/f_no_cache_corrupt_inode/image.gz new file mode 100644 index 0000000000000000000000000000000000000000..e17e9216deac289cf5c13a33be87b1810640a66d GIT binary patch literal 2606 zcmb2|=3wyobSapL`Ry(14Bh7a#A{ZQZy>*8x|QnKm@V3(D-?OG_n)#_yJ!7jME zccFxPCX1kBt6$TLWsAF;`vY|rJyPTFYwCAAxQJ1dedE2Sil)~bqkGT(t$SEM{r$V5 z^84lefA)JjF&#ou0{Bmr4M&rwy6_4VU%juSV`?OqhEd#^L$xHU%EzDW< z?ElgobJqIRTYdVPt0{6lLy>`jA>!Y&Pd7g-O%|Nb4&?o-KKcItPl425PH*=!{G4#| z%h#*_4)4}`VkCStd1)?t_wjx?k7unP7OYm*66uzk1JrTANZ|X^`FE>t1i#FA^?(1n zRbT%zGB7lJd+|SCBD&hV^8Z5bYM?TQ-QWIe?>@c^EbH)J9w?O2|IZ#sfxw16qFqPl zgh4nsNrku1cFj5klyeZLW0GZ$0}^eC_)0ZyanQqF4VdL)|HA^P`SDl!%e