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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
ocfs2: fix regression in ocfs2_read_blocks_sync()
We're panicing in ocfs2_read_blocks_sync() if a jbd-managed buffer is seen.
At first glance, this seems ok but in reality it can happen. My test case
was to just run 'exorcist'. A struct inode is being pushed out of memory but
is then re-read at a later time, before the buffer has been checkpointed by
jbd. This causes a BUG to be hit in ocfs2_read_blocks_sync().
Reviewed-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
+4
-11
fs/ocfs2/buffer_head_io.c
+4
-11
fs/ocfs2/buffer_head_io.c
···
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bh = bhs[i];
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if (buffer_jbd(bh)) {
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-
mlog(ML_ERROR,
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+
mlog(ML_BH_IO,
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"trying to sync read a jbd "
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"managed bh (blocknr = %llu), skipping\n",
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(unsigned long long)bh->b_blocknr);
···
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for (i = nr; i > 0; i--) {
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bh = bhs[i - 1];
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-
if (buffer_jbd(bh)) {
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-
mlog(ML_ERROR,
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-
"the journal got the buffer while it was "
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-
"locked for io! (blocknr = %llu)\n",
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-
(unsigned long long)bh->b_blocknr);
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-
BUG();
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-
}
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+
/* No need to wait on the buffer if it's managed by JBD. */
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+
if (!buffer_jbd(bh))
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+
wait_on_buffer(bh);
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-
wait_on_buffer(bh);
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if (!buffer_uptodate(bh)) {
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/* Status won't be cleared from here on out,
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* so we can safely record this and loop back
···
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ignore_cache = 1;
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}
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-
/* XXX: Can we ever get this and *not* have the cached
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-
* flag set? */
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if (buffer_jbd(bh)) {
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if (ignore_cache)
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mlog(ML_BH_IO, "trying to sync read a jbd "