Error recovery in ext4_alloc_branch() calls ext4_forget() even for buffer corresponding to indirect block it did not allocate. This leads to brelse() being called twice for that buffer (once from ext4_forget() and once from cleanup in ext4_ind_map_blocks()) leading to buffer use count misaccounting. Eventually (but often much later because there are other users of the buffer) we will see messages like: VFS: brelse: Trying to free free buffer
Another manifestation of this problem is an error: JBD2 unexpected failure: jbd2_journal_revoke: !buffer_revoked(bh); inconsistent data on disk The fix is easy - don't forget buffer we did not allocate. Also add an explanatory comment because the indexing at ext4_alloc_branch() is somewhat subtle. Signed-off-by: Jan Kara <[email protected]> --- fs/ext4/indirect.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 594009f5f523..3b91d240da4d 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -389,7 +389,13 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode, return 0; failed: for (; i >= 0; i--) { - if (i != indirect_blks && branch[i].bh) + /* + * We want to ext4_forget() only freshly allocated indirect + * blocks. Buffer for new_blocks[i-1] is at branch[i].bh and + * buffer at branch[0].bh is indirect block / inode already + * existing before ext4_alloc_branch() was called. + */ + if (i > 0 && i != indirect_blks && branch[i].bh) ext4_forget(handle, 1, inode, branch[i].bh, branch[i].bh->b_blocknr); ext4_free_blocks(handle, inode, NULL, new_blocks[i], -- 1.8.1.4 ------------------------------------------------------------------------------ Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk _______________________________________________ Jfs-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jfs-discussion
