@@ -2956,14 +2956,17 @@ xfs_read_agf(
trace_xfs_read_agf(mp, agno);
ASSERT(agno != NULLAGNUMBER);
- error = xfs_trans_read_buf(
- mp, tp, mp->m_ddev_targp,
+ error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
+ /*
+ * Callers of xfs_read_agf() currently interpret a NULL bpp as EAGAIN
+ * and need to be converted to check for EAGAIN specifically.
+ */
+ if (error == -EAGAIN)
+ return 0;
if (error)
return error;
- if (!*bpp)
- return 0;
ASSERT(!(*bpp)->b_error);
xfs_buf_set_ref(*bpp, XFS_AGF_REF);
@@ -422,16 +422,6 @@ xfs_attr_rmtval_get(
&xfs_attr3_rmt_buf_ops);
if (!bp)
return -ENOMEM;
- error = bp->b_error;
- if (error) {
- xfs_buf_ioerror_alert(bp, __func__);
- xfs_buf_relse(bp);
-
- /* bad CRC means corrupted metadata */
- if (error == -EFSBADCRC)
- error = -EFSCORRUPTED;
- return error;
- }
error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino,
&offset, &valuelen,
@@ -796,47 +796,76 @@ xfs_buf_reverify(
return bp->b_error;
}
-xfs_buf_t *
+int
xfs_buf_read_map(
struct xfs_buftarg *target,
struct xfs_buf_map *map,
int nmaps,
xfs_buf_flags_t flags,
+ struct xfs_buf **bpp,
const struct xfs_buf_ops *ops)
{
struct xfs_buf *bp;
int error;
flags |= XBF_READ;
+ *bpp = NULL;
error = xfs_buf_get_map(target, map, nmaps, flags, &bp);
if (error)
- return NULL;
+ return error;
trace_xfs_buf_read(bp, flags, _RET_IP_);
if (!(bp->b_flags & XBF_DONE)) {
+ /* Initiate the buffer read and wait. */
XFS_STATS_INC(target->bt_mount, xb_get_read);
bp->b_ops = ops;
- _xfs_buf_read(bp, flags);
- return bp;
+ error = _xfs_buf_read(bp, flags);
+
+ /* Readahead iodone already dropped the buffer, so exit. */
+ if (flags & XBF_ASYNC)
+ return 0;
+ } else {
+ /* Buffer already read; all we need to do is check it. */
+ error = xfs_buf_reverify(bp, ops);
+
+ /* Readahead already finished; drop the buffer and exit. */
+ if (flags & XBF_ASYNC) {
+ xfs_buf_relse(bp);
+ return 0;
+ }
+
+ /* We do not want read in the flags */
+ bp->b_flags &= ~XBF_READ;
+ ASSERT(bp->b_ops != NULL || ops == NULL);
}
- xfs_buf_reverify(bp, ops);
+ /*
+ * If we've had a read error, then the contents of the buffer are
+ * invalid and should not be used. To ensure that a followup read tries
+ * to pull the buffer from disk again, we clear the XBF_DONE flag and
+ * mark the buffer stale. This ensures that anyone who has a current
+ * reference to the buffer will interpret it's contents correctly and
+ * future cache lookups will also treat it as an empty, uninitialised
+ * buffer.
+ */
+ if (error) {
+ if (!XFS_FORCED_SHUTDOWN(target->bt_mount))
+ xfs_buf_ioerror_alert(bp, __func__);
- if (flags & XBF_ASYNC) {
- /*
- * Read ahead call which is already satisfied,
- * drop the buffer
- */
+ bp->b_flags &= ~XBF_DONE;
+ xfs_buf_stale(bp);
xfs_buf_relse(bp);
- return NULL;
+
+ /* bad CRC means corrupted metadata */
+ if (error == -EFSBADCRC)
+ error = -EFSCORRUPTED;
+ return error;
}
- /* We do not want read in the flags */
- bp->b_flags &= ~XBF_READ;
- ASSERT(bp->b_ops != NULL || ops == NULL);
- return bp;
+ *bpp = bp;
+ return 0;
}
/*
@@ -850,11 +879,13 @@ xfs_buf_readahead_map(
int nmaps,
const struct xfs_buf_ops *ops)
{
+ struct xfs_buf *bp;
+
if (bdi_read_congested(target->bt_bdev->bd_bdi))
return;
xfs_buf_read_map(target, map, nmaps,
- XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops);
+ XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops);
}
/*
@@ -194,10 +194,9 @@ struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target,
int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
-struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target,
- struct xfs_buf_map *map, int nmaps,
- xfs_buf_flags_t flags,
- const struct xfs_buf_ops *ops);
+int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
+ int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
+ const struct xfs_buf_ops *ops);
void xfs_buf_readahead_map(struct xfs_buftarg *target,
struct xfs_buf_map *map, int nmaps,
const struct xfs_buf_ops *ops);
@@ -226,8 +225,14 @@ xfs_buf_read(
xfs_buf_flags_t flags,
const struct xfs_buf_ops *ops)
{
+ struct xfs_buf *bp;
+ int error;
DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
- return xfs_buf_read_map(target, &map, 1, flags, ops);
+
+ error = xfs_buf_read_map(target, &map, 1, flags, &bp, ops);
+ if (error)
+ return NULL;
+ return bp;
}
static inline void
@@ -2749,11 +2749,6 @@ xlog_recover_buffer_pass2(
buf_flags, NULL);
if (!bp)
return -ENOMEM;
- error = bp->b_error;
- if (error) {
- xfs_buf_ioerror_alert(bp, "xlog_recover_do..(read#1)");
- goto out_release;
- }
/*
* Recover the buffer only if we get an LSN from it and it's less than
@@ -2956,11 +2951,6 @@ xlog_recover_inode_pass2(
error = -ENOMEM;
goto error;
}
- error = bp->b_error;
- if (error) {
- xfs_buf_ioerror_alert(bp, "xlog_recover_do..(read#2)");
- goto out_release;
- }
ASSERT(in_f->ilf_fields & XFS_ILOG_CORE);
dip = xfs_buf_offset(bp, in_f->ilf_boffset);
@@ -57,16 +57,6 @@ xfs_readlink_bmap_ilocked(
&xfs_symlink_buf_ops);
if (!bp)
return -ENOMEM;
- error = bp->b_error;
- if (error) {
- xfs_buf_ioerror_alert(bp, __func__);
- xfs_buf_relse(bp);
-
- /* bad CRC means corrupted metadata */
- if (error == -EFSBADCRC)
- error = -EFSCORRUPTED;
- goto out;
- }
byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
if (pathlen < byte_cnt)
byte_cnt = pathlen;
@@ -302,36 +302,16 @@ xfs_trans_read_buf_map(
return 0;
}
- bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
- if (!bp) {
- if (!(flags & XBF_TRYLOCK))
- return -ENOMEM;
- return tp ? 0 : -EAGAIN;
- }
-
- /*
- * If we've had a read error, then the contents of the buffer are
- * invalid and should not be used. To ensure that a followup read tries
- * to pull the buffer from disk again, we clear the XBF_DONE flag and
- * mark the buffer stale. This ensures that anyone who has a current
- * reference to the buffer will interpret it's contents correctly and
- * future cache lookups will also treat it as an empty, uninitialised
- * buffer.
- */
- if (bp->b_error) {
- error = bp->b_error;
- if (!XFS_FORCED_SHUTDOWN(mp))
- xfs_buf_ioerror_alert(bp, __func__);
- bp->b_flags &= ~XBF_DONE;
- xfs_buf_stale(bp);
-
+ error = xfs_buf_read_map(target, map, nmaps, flags, &bp, ops);
+ switch (error) {
+ case 0:
+ break;
+ default:
if (tp && (tp->t_flags & XFS_TRANS_DIRTY))
xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR);
- xfs_buf_relse(bp);
-
- /* bad CRC means corrupted metadata */
- if (error == -EFSBADCRC)
- error = -EFSCORRUPTED;
+ /* fall through */
+ case -ENOMEM:
+ case -EAGAIN:
return error;
}