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authorTheodore Ts'o <tytso@mit.edu>2021-05-03 15:37:33 -0400
committerTheodore Ts'o <tytso@mit.edu>2021-08-10 10:11:20 -0400
commita20d1cebb98bba75f2e34fddc768dd8712c1bded (patch)
tree49ffbb246941e9198f9820437ee5e5ac38aac106 /fs
parent877ba3f729fd3d8ef0e29bc2a55e57cfa54b2e43 (diff)
jbd2: fix portability problems caused by unaligned accesses
This commit applies the e2fsck/recovery.c portions of commit 1e0c8ca7c08a ("e2fsck: fix portability problems caused by unaligned accesses) from the e2fsprogs git tree. The on-disk format for the ext4 journal can have unaigned 32-bit integers. This can happen when replaying a journal using a obsolete checksum format (which was never popularly used, since the v3 format replaced v2 while the metadata checksum feature was being stablized). Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs')
-rw-r--r--fs/jbd2/recovery.c22
1 files changed, 11 insertions, 11 deletions
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index d47a0d96bf30..4c4209262437 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -196,7 +196,7 @@ static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf)
static int count_tags(journal_t *journal, struct buffer_head *bh)
{
char * tagp;
- journal_block_tag_t * tag;
+ journal_block_tag_t tag;
int nr = 0, size = journal->j_blocksize;
int tag_bytes = journal_tag_bytes(journal);
@@ -206,14 +206,14 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
tagp = &bh->b_data[sizeof(journal_header_t)];
while ((tagp - bh->b_data + tag_bytes) <= size) {
- tag = (journal_block_tag_t *) tagp;
+ memcpy(&tag, tagp, sizeof(tag));
nr++;
tagp += tag_bytes;
- if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
+ if (!(tag.t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
tagp += 16;
- if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
+ if (tag.t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
break;
}
@@ -433,9 +433,9 @@ 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,
+ journal_block_tag3_t *tag3,
void *buf, __u32 sequence)
{
- journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
__u32 csum32;
__be32 seq;
@@ -496,7 +496,7 @@ static int do_one_pass(journal_t *journal,
while (1) {
int flags;
char * tagp;
- journal_block_tag_t * tag;
+ journal_block_tag_t tag;
struct buffer_head * obh;
struct buffer_head * nbh;
@@ -613,8 +613,8 @@ static int do_one_pass(journal_t *journal,
<= journal->j_blocksize - descr_csum_size) {
unsigned long io_block;
- tag = (journal_block_tag_t *) tagp;
- flags = be16_to_cpu(tag->t_flags);
+ memcpy(&tag, tagp, sizeof(tag));
+ flags = be16_to_cpu(tag.t_flags);
io_block = next_log_block++;
wrap(journal, next_log_block);
@@ -632,7 +632,7 @@ static int do_one_pass(journal_t *journal,
J_ASSERT(obh != NULL);
blocknr = read_tag_block(journal,
- tag);
+ &tag);
/* If the block has been
* revoked, then we're all done
@@ -647,8 +647,8 @@ static int do_one_pass(journal_t *journal,
/* Look for block corruption */
if (!jbd2_block_tag_csum_verify(
- journal, tag, obh->b_data,
- be32_to_cpu(tmp->h_sequence))) {
+ journal, &tag, (journal_block_tag3_t *)tagp,
+ obh->b_data, be32_to_cpu(tmp->h_sequence))) {
brelse(obh);
success = -EFSBADCRC;
printk(KERN_ERR "JBD2: Invalid "