When writing block numbers into a journal descriptor block, don't write
the top 32 bits of a tag unless we're using a 64-bit journal. That
avoids any possibility of overflowing off the end of the descriptor
block in the case where the last 32-bit tag only just fits into the
descriptor block.
Also cleans up the tag handling slightly by introducing new macros for
the size of 32- and 64-bit descriptor tags.
Signed-off-by: Stephen Tweedie <[email protected]>
Acked-by: Badari Pulavarty <[email protected]>
---
linux-2.6.17-ming/fs/jbd/commit.c | 11 ++++++-----
linux-2.6.17-ming/include/linux/jbd.h | 3 +++
2 files changed, 9 insertions(+), 5 deletions(-)
diff -puN fs/jbd/commit.c~jbd-avoid-blk-overflow-write-journal-metadata-tag fs/jbd/commit.c
--- linux-2.6.17/fs/jbd/commit.c~jbd-avoid-blk-overflow-write-journal-metadata-tag 2006-06-28 16:46:58.783710948 -0700
+++ linux-2.6.17-ming/fs/jbd/commit.c 2006-06-28 16:46:58.791710030 -0700
@@ -160,10 +160,12 @@ static int journal_write_commit_record(j
return (ret == -EIO);
}
-static inline void write_split_be64(__be32 *high, __be32 *low, u64 val)
+static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
+ sector_t block)
{
- *low = cpu_to_be32(val & (u32)~0);
- *high = cpu_to_be32(val >> 32);
+ tag->t_blocknr = cpu_to_be32(block & (u32)~0);
+ if (tag_bytes > JBD_TAG_SIZE32)
+ tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
}
/*
@@ -560,8 +562,7 @@ write_out_data:
tag_flag |= JFS_FLAG_SAME_UUID;
tag = (journal_block_tag_t *) tagp;
- write_split_be64(&tag->t_blocknr_high, &tag->t_blocknr,
- jh2bh(jh)->b_blocknr);
+ write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
tag->t_flags = cpu_to_be32(tag_flag);
tagp += tag_bytes;
space_left -= tag_bytes;
diff -puN include/linux/jbd.h~jbd-avoid-blk-overflow-write-journal-metadata-tag include/linux/jbd.h
--- linux-2.6.17/include/linux/jbd.h~jbd-avoid-blk-overflow-write-journal-metadata-tag 2006-06-28 16:46:58.787710489 -0700
+++ linux-2.6.17-ming/include/linux/jbd.h 2006-06-28 16:46:58.793709801 -0700
@@ -159,6 +159,9 @@ typedef struct journal_block_tag_s
__be32 t_blocknr_high; /* most-significant high 32bits. */
} journal_block_tag_t;
+#define JBD_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high))
+#define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t))
+
/*
* The revoke descriptor: used on disk to describe a series of blocks to
* be revoked from the log
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
