tbio->bi_rw = WRITE;
tbio->bi_private = r10_bio;
tbio->bi_iter.bi_sector = r10_bio->devs[i].addr;
+From: Dave Chinner <dchinner@redhat.com>
+
+When we do dquot readahead in log recovery, we do not use a verifier
+as the underlying buffer may not have dquots in it. e.g. the
+allocation operation hasn't yet been replayed. Hence we do not want
+to fail recovery because we detect an operation to be replayed has
+not been run yet. This problem was addressed for inodes in commit
+d891400 ("xfs: inode buffers may not be valid during recovery
+readahead") but the problem was not recognised to exist for dquots
+and their buffers as the dquot readahead did not have a verifier.
+
+The result of not using a verifier is that when the buffer is then
+next read to replay a dquot modification, the dquot buffer verifier
+will only be attached to the buffer if *readahead is not complete*.
+Hence we can read the buffer, replay the dquot changes and then add
+it to the delwri submission list without it having a verifier
+attached to it. This then generates warnings in xfs_buf_ioapply(),
+which catches and warns about this case.
+
+Fix this and make it handle the same readahead verifier error cases
+as for inode buffers by adding a new readahead verifier that has a
+write operation as well as a read operation that marks the buffer as
+not done if any corruption is detected. Also make sure we don't run
+readahead if the dquot buffer has been marked as cancelled by
+recovery.
+
+This will result in readahead either succeeding and the buffer
+having a valid write verifier, or readahead failing and the buffer
+state requiring the subsequent read to resubmit the IO with the new
+verifier. In either case, this will result in the buffer always
+ending up with a valid write verifier on it.
+
+Note: we also need to fix the inode buffer readahead error handling
+to mark the buffer with EIO. Brian noticed the code I copied from
+there wrong during review, so fix it at the same time. Add comments
+linking the two functions that handle readahead verifier errors
+together so we don't forget this behavioural link in future.
+
+cc: <stable@vger.kernel.org> # 3.12 - current
+Signed-off-by: Dave Chinner <dchinner@redhat.com>
+---
+
+Version 2
+- fix logic error in determining if verify failed
+- set error on buffer when verifier fails
+- fix inode buffer readahead verifier to set error when it fails
+- better comments, link dquot and inode buffer ra verifiers in the
+ comments
+
+ fs/xfs/libxfs/xfs_dquot_buf.c | 36 ++++++++++++++++++++++++++++++------
+ fs/xfs/libxfs/xfs_inode_buf.c | 14 +++++++++-----
+ fs/xfs/libxfs/xfs_quota_defs.h | 2 +-
+ fs/xfs/libxfs/xfs_shared.h | 1 +
+ fs/xfs/xfs_log_recover.c | 9 +++++++--
+ 5 files changed, 48 insertions(+), 14 deletions(-)
+
+diff --git a/fs/xfs/libxfs/xfs_dquot_buf.c b/fs/xfs/libxfs/xfs_dquot_buf.c
+index 11cefb2..3cc3cf7 100644
+--- a/fs/xfs/libxfs/xfs_dquot_buf.c
++++ b/fs/xfs/libxfs/xfs_dquot_buf.c
+@@ -54,7 +54,7 @@ xfs_dqcheck(
+ xfs_dqid_t id,
+ uint type, /* used only when IO_dorepair is true */
+ uint flags,
+- char *str)
++ const char *str)
+ {
+ xfs_dqblk_t *d = (xfs_dqblk_t *)ddq;
+ int errs = 0;
+@@ -207,7 +207,8 @@ xfs_dquot_buf_verify_crc(
+ STATIC bool
+ xfs_dquot_buf_verify(
+ struct xfs_mount *mp,
+- struct xfs_buf *bp)
++ struct xfs_buf *bp,
++ int warn)
+ {
+ struct xfs_dqblk *d = (struct xfs_dqblk *)bp->b_addr;
+ xfs_dqid_t id = 0;
+@@ -240,8 +241,7 @@ xfs_dquot_buf_verify(
+ if (i == 0)
+ id = be32_to_cpu(ddq->d_id);
+
+- error = xfs_dqcheck(mp, ddq, id + i, 0, XFS_QMOPT_DOWARN,
+- "xfs_dquot_buf_verify");
++ error = xfs_dqcheck(mp, ddq, id + i, 0, warn, __func__);
+ if (error)
+ return false;
+ }
+@@ -256,7 +256,7 @@ xfs_dquot_buf_read_verify(
+
+ if (!xfs_dquot_buf_verify_crc(mp, bp))
+ xfs_buf_ioerror(bp, -EFSBADCRC);
+- else if (!xfs_dquot_buf_verify(mp, bp))
++ else if (!xfs_dquot_buf_verify(mp, bp, XFS_QMOPT_DOWARN))
+ xfs_buf_ioerror(bp, -EFSCORRUPTED);
+
+ if (bp->b_error)
+@@ -264,6 +264,25 @@ xfs_dquot_buf_read_verify(
+ }
+
+ /*
++ * readahead errors are silent and simply leave the buffer as !done so a real
++ * read will then be run with the xfs_dquot_buf_ops verifier. See
++ * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
++ * reporting the failure.
++ */
++static void
++xfs_dquot_buf_readahead_verify(
++ struct xfs_buf *bp)
++{
++ struct xfs_mount *mp = bp->b_target->bt_mount;
++
++ if (!xfs_dquot_buf_verify_crc(mp, bp) ||
++ !xfs_dquot_buf_verify(mp, bp, 0)) {
++ xfs_buf_ioerror(bp, -EIO);
++ bp->b_flags &= ~XBF_DONE;
++ }
++}
++
++/*
+ * we don't calculate the CRC here as that is done when the dquot is flushed to
+ * the buffer after the update is done. This ensures that the dquot in the
+ * buffer always has an up-to-date CRC value.
+@@ -274,7 +293,7 @@ xfs_dquot_buf_write_verify(
+ {
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+
+- if (!xfs_dquot_buf_verify(mp, bp)) {
++ if (!xfs_dquot_buf_verify(mp, bp, XFS_QMOPT_DOWARN)) {
+ xfs_buf_ioerror(bp, -EFSCORRUPTED);
+ xfs_verifier_error(bp);
+ return;
+@@ -287,3 +306,8 @@ const struct xfs_buf_ops xfs_dquot_buf_ops = {
+ .verify_write = xfs_dquot_buf_write_verify,
+ };
+
++const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
++
++ .verify_read = xfs_dquot_buf_readahead_verify,
++ .verify_write = xfs_dquot_buf_write_verify,
++};
+diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
+index 1b8d98a..4816209 100644
+--- a/fs/xfs/libxfs/xfs_inode_buf.c
++++ b/fs/xfs/libxfs/xfs_inode_buf.c
+@@ -62,11 +62,14 @@ xfs_inobp_check(
+ * has not had the inode cores stamped into it. Hence for readahead, the buffer
+ * may be potentially invalid.
+ *
+- * If the readahead buffer is invalid, we don't want to mark it with an error,
+- * but we do want to clear the DONE status of the buffer so that a followup read
+- * will re-read it from disk. This will ensure that we don't get an unnecessary
+- * warnings during log recovery and we don't get unnecssary panics on debug
+- * kernels.
++ * If the readahead buffer is invalid, we need to mark it with an error and
++ * clear the DONE status of the buffer so that a followup read will re-read it
++ * from disk. We don't report the error otherwise to avoid warnings during log
++ * recovery and we don't get unnecssary panics on debug kernels. We use EIO here
++ * because all we want to do is say readahead failed; there is no-one to report
++ * the error to, so this will distinguish it from a non-ra verifier failure.
++ * Changes to this readahead error behavour also need to be reflected in
++ * xfs_dquot_buf_readahead_verify().
+ */
+ static void
+ xfs_inode_buf_verify(
+@@ -92,6 +95,7 @@ xfs_inode_buf_verify(
+ XFS_ERRTAG_ITOBP_INOTOBP,
+ XFS_RANDOM_ITOBP_INOTOBP))) {
+ if (readahead) {
++ xfs_buf_ioerror(bp, -EIO);
+ bp->b_flags &= ~XBF_DONE;
+ return;
+ }
+diff --git a/fs/xfs/libxfs/xfs_quota_defs.h b/fs/xfs/libxfs/xfs_quota_defs.h
+index 1b0a083..f51078f 100644
+--- a/fs/xfs/libxfs/xfs_quota_defs.h
++++ b/fs/xfs/libxfs/xfs_quota_defs.h
+@@ -153,7 +153,7 @@ typedef __uint16_t xfs_qwarncnt_t;
+ #define XFS_QMOPT_RESBLK_MASK (XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_RES_RTBLKS)
+
+ extern int xfs_dqcheck(struct xfs_mount *mp, xfs_disk_dquot_t *ddq,
+- xfs_dqid_t id, uint type, uint flags, char *str);
++ xfs_dqid_t id, uint type, uint flags, const char *str);
+ extern int xfs_calc_dquots_per_chunk(unsigned int nbblks);
+
+ #endif /* __XFS_QUOTA_H__ */
+diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h
+index 5be5297..15c3ceb 100644
+--- a/fs/xfs/libxfs/xfs_shared.h
++++ b/fs/xfs/libxfs/xfs_shared.h
+@@ -49,6 +49,7 @@ extern const struct xfs_buf_ops xfs_inobt_buf_ops;
+ extern const struct xfs_buf_ops xfs_inode_buf_ops;
+ extern const struct xfs_buf_ops xfs_inode_buf_ra_ops;
+ extern const struct xfs_buf_ops xfs_dquot_buf_ops;
++extern const struct xfs_buf_ops xfs_dquot_buf_ra_ops;
+ extern const struct xfs_buf_ops xfs_sb_buf_ops;
+ extern const struct xfs_buf_ops xfs_sb_quiet_buf_ops;
+ extern const struct xfs_buf_ops xfs_symlink_buf_ops;
+diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
+index 26e67b4..da37beb 100644
+--- a/fs/xfs/xfs_log_recover.c
++++ b/fs/xfs/xfs_log_recover.c
+@@ -3521,6 +3521,7 @@ xlog_recover_dquot_ra_pass2(
+ struct xfs_disk_dquot *recddq;
+ struct xfs_dq_logformat *dq_f;
+ uint type;
++ int len;
+
+
+ if (mp->m_qflags == 0)
+@@ -3541,8 +3542,12 @@ xlog_recover_dquot_ra_pass2(
+ ASSERT(dq_f);
+ ASSERT(dq_f->qlf_len == 1);
+
+- xfs_buf_readahead(mp->m_ddev_targp, dq_f->qlf_blkno,
+- XFS_FSB_TO_BB(mp, dq_f->qlf_len), NULL);
++ len = XFS_FSB_TO_BB(mp, dq_f->qlf_len);
++ if (xlog_peek_buffer_cancelled(log, dq_f->qlf_blkno, len, 0))
++ return;
++
++ xfs_buf_readahead(mp->m_ddev_targp, dq_f->qlf_blkno, len,
++ &xfs_dquot_buf_ra_ops);
+ }
+
+ STATIC void
+
+_______________________________________________
+xfs mailing list
+xfs@oss.sgi.com
+http://oss.sgi.com/mailman/listinfo/xfs
projects / packages / kernel.git / commitdiff