summaryrefslogtreecommitdiff
path: root/fs/jbd2/commit.c
diff options
context:
space:
mode:
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/commit.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/commit.c')
-rw-r--r--fs/jbd2/commit.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 6fac74349856..b73e0215baa7 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -97,7 +97,7 @@ static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
struct commit_header *h;
__u32 csum;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return;
h = (struct commit_header *)(bh->b_data);
@@ -313,11 +313,11 @@ static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
return checksum;
}
-static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
+static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
unsigned long long block)
{
tag->t_blocknr = cpu_to_be32(block & (u32)~0);
- if (tag_bytes > JBD2_TAG_SIZE32)
+ if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_64BIT))
tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
}
@@ -327,7 +327,7 @@ static void jbd2_descr_block_csum_set(journal_t *j,
struct jbd2_journal_block_tail *tail;
__u32 csum;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return;
tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
@@ -340,12 +340,13 @@ static void jbd2_descr_block_csum_set(journal_t *j,
static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
struct buffer_head *bh, __u32 sequence)
{
+ journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
struct page *page = bh->b_page;
__u8 *addr;
__u32 csum32;
__be32 seq;
- if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (!jbd2_journal_has_csum_v2or3(j))
return;
seq = cpu_to_be32(sequence);
@@ -355,8 +356,10 @@ static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
bh->b_size);
kunmap_atomic(addr);
- /* We only have space to store the lower 16 bits of the crc32c. */
- tag->t_checksum = cpu_to_be16(csum32);
+ if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+ tag3->t_checksum = cpu_to_be32(csum32);
+ else
+ tag->t_checksum = cpu_to_be16(csum32);
}
/*
* jbd2_journal_commit_transaction
@@ -396,7 +399,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
LIST_HEAD(io_bufs);
LIST_HEAD(log_bufs);
- if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (jbd2_journal_has_csum_v2or3(journal))
csum_size = sizeof(struct jbd2_journal_block_tail);
/*
@@ -690,7 +693,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
tag_flag |= JBD2_FLAG_SAME_UUID;
tag = (journal_block_tag_t *) tagp;
- write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
+ write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
tag->t_flags = cpu_to_be16(tag_flag);
jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
commit_transaction->t_tid);