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authorDarrick J. Wong <darrick.wong@oracle.com>2014-08-27 18:40:07 -0400
committerTheodore Ts'o <tytso@mit.edu>2014-08-28 22:22:29 -0400
commitdb9ee220361de03ee86388f9ea5e529eaad5323c (patch)
tree1f5047f2f588e814901be723a989adde97ae5093 /fs/jbd2/recovery.c
parent022eaa7517017efe4f6538750c2b59a804dc7df7 (diff)
jbd2: fix descriptor block size handling errors with journal_csum
It turns out that there are some serious problems with the on-disk format of journal checksum v2. The foremost is that the function to calculate descriptor tag size returns sizes that are too big. This causes alignment issues on some architectures and is compounded by the fact that some parts of jbd2 use the structure size (incorrectly) to determine the presence of a 64bit journal instead of checking the feature flags. Therefore, introduce journal checksum v3, which enlarges the descriptor block tag format to allow for full 32-bit checksums of journal blocks, fix the journal tag function to return the correct sizes, and fix the jbd2 recovery code to use feature flags to determine 64bitness. Add a few function helpers so we don't have to open-code quite so many pieces. Switching to a 16-byte block size was found to increase journal size overhead by a maximum of 0.1%, to convert a 32-bit journal with no checksumming to a 32-bit journal with checksum v3 enabled. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: TR Reardon <thomas_reardon@hotmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
Diffstat (limited to 'fs/jbd2/recovery.c')
-rw-r--r--fs/jbd2/recovery.c26
1 files changed, 15 insertions, 11 deletions
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 00e9703d7dc6..9b329b55ffe3 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -181,7 +181,7 @@ static int jbd2_descr_block_csum_verify(journal_t *j,
__be32 provided;
__u32 calculated;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return 1;
tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
@@ -205,7 +205,7 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
int nr = 0, size = journal->j_blocksize;
int tag_bytes = journal_tag_bytes(journal);
- if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (jbd2_journal_has_csum_v2or3(journal))
size -= sizeof(struct jbd2_journal_block_tail);
tagp = &bh->b_data[sizeof(journal_header_t)];
@@ -338,10 +338,11 @@ int jbd2_journal_skip_recovery(journal_t *journal)
return err;
}
-static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
+static inline unsigned long long read_tag_block(journal_t *journal,
+ journal_block_tag_t *tag)
{
unsigned long long block = be32_to_cpu(tag->t_blocknr);
- if (tag_bytes > JBD2_TAG_SIZE32)
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
return block;
}
@@ -384,7 +385,7 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
__be32 provided;
__u32 calculated;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return 1;
h = buf;
@@ -399,17 +400,21 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
void *buf, __u32 sequence)
{
+ journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
__u32 csum32;
__be32 seq;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return 1;
seq = cpu_to_be32(sequence);
csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
- return tag->t_checksum == cpu_to_be16(csum32);
+ if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+ return tag3->t_checksum == cpu_to_be32(csum32);
+ else
+ return tag->t_checksum == cpu_to_be16(csum32);
}
static int do_one_pass(journal_t *journal,
@@ -513,8 +518,7 @@ static int do_one_pass(journal_t *journal,
switch(blocktype) {
case JBD2_DESCRIPTOR_BLOCK:
/* Verify checksum first */
- if (JBD2_HAS_INCOMPAT_FEATURE(journal,
- JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (jbd2_journal_has_csum_v2or3(journal))
descr_csum_size =
sizeof(struct jbd2_journal_block_tail);
if (descr_csum_size > 0 &&
@@ -575,7 +579,7 @@ static int do_one_pass(journal_t *journal,
unsigned long long blocknr;
J_ASSERT(obh != NULL);
- blocknr = read_tag_block(tag_bytes,
+ blocknr = read_tag_block(journal,
tag);
/* If the block has been
@@ -814,7 +818,7 @@ static int jbd2_revoke_block_csum_verify(journal_t *j,
__be32 provided;
__u32 calculated;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return 1;
tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -