* cache hits, as metadata intensive workloads will see 3 orders of magnitude
* more hits than misses.
*/
-struct xfs_buf *
+int
xfs_buf_get_map(
struct xfs_buftarg *target,
struct xfs_buf_map *map,
int nmaps,
- xfs_buf_flags_t flags)
+ xfs_buf_flags_t flags,
+ struct xfs_buf **bpp)
{
struct xfs_buf *bp;
struct xfs_buf *new_bp;
int error = 0;
+ *bpp = NULL;
error = xfs_buf_find(target, map, nmaps, flags, NULL, &bp);
-
- switch (error) {
- case 0:
- /* cache hit */
+ if (!error)
goto found;
- case -EAGAIN:
- /* cache hit, trylock failure, caller handles failure */
- ASSERT(flags & XBF_TRYLOCK);
- return NULL;
- case -ENOENT:
- /* cache miss, go for insert */
- break;
- case -EFSCORRUPTED:
- default:
- /*
- * None of the higher layers understand failure types
- * yet, so return NULL to signal a fatal lookup error.
- */
- return NULL;
- }
+ if (error != -ENOENT)
+ return error;
error = _xfs_buf_alloc(target, map, nmaps, flags, &new_bp);
if (error)
- return NULL;
+ return error;
error = xfs_buf_allocate_memory(new_bp, flags);
if (error) {
xfs_buf_free(new_bp);
- return NULL;
+ return error;
}
error = xfs_buf_find(target, map, nmaps, flags, new_bp, &bp);
if (error) {
xfs_buf_free(new_bp);
- return NULL;
+ return error;
}
if (bp != new_bp)
xfs_warn(target->bt_mount,
"%s: failed to map pagesn", __func__);
xfs_buf_relse(bp);
- return NULL;
+ return error;
}
}
XFS_STATS_INC(target->bt_mount, xb_get);
trace_xfs_buf_get(bp, flags, _RET_IP_);
- return bp;
+ *bpp = bp;
+ return 0;
}
STATIC int
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,
- const struct xfs_buf_ops *ops)
+ struct xfs_buf **bpp,
+ const struct xfs_buf_ops *ops,
+ xfs_failaddr_t fa)
{
struct xfs_buf *bp;
+ int error;
flags |= XBF_READ;
+ *bpp = NULL;
- bp = xfs_buf_get_map(target, map, nmaps, flags);
- if (!bp)
- return NULL;
+ error = xfs_buf_get_map(target, map, nmaps, flags, &bp);
+ if (error)
+ 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, fa);
- 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;
}
/*
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,
+ __this_address);
}
/*
const struct xfs_buf_ops *ops)
{
struct xfs_buf *bp;
+ int error;
*bpp = NULL;
- bp = xfs_buf_get_uncached(target, numblks, flags);
- if (!bp)
- return -ENOMEM;
+ error = xfs_buf_get_uncached(target, numblks, flags, &bp);
+ if (error)
+ return error;
/* set up the buffer for a read IO */
ASSERT(bp->b_map_count == 1);
xfs_buf_submit(bp);
if (bp->b_error) {
- int error = bp->b_error;
+ error = bp->b_error;
xfs_buf_relse(bp);
return error;
}
return 0;
}
-xfs_buf_t *
+int
xfs_buf_get_uncached(
struct xfs_buftarg *target,
size_t numblks,
- int flags)
+ int flags,
+ struct xfs_buf **bpp)
{
unsigned long page_count;
int error, i;
struct xfs_buf *bp;
DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks);
+ *bpp = NULL;
+
/* flags might contain irrelevant bits, pass only what we care about */
error = _xfs_buf_alloc(target, &map, 1, flags & XBF_NO_IOACCT, &bp);
if (error)
for (i = 0; i < page_count; i++) {
bp->b_pages[i] = alloc_page(xb_to_gfp(flags));
- if (!bp->b_pages[i])
+ if (!bp->b_pages[i]) {
+ error = -ENOMEM;
goto fail_free_mem;
+ }
}
bp->b_flags |= _XBF_PAGES;
}
trace_xfs_buf_get_uncached(bp, _RET_IP_);
- return bp;
+ *bpp = bp;
+ return 0;
fail_free_mem:
while (--i >= 0)
xfs_buf_free_maps(bp);
kmem_cache_free(xfs_buf_zone, bp);
fail:
- return NULL;
+ return error;
}
/*
void
xfs_buf_ioerror_alert(
struct xfs_buf *bp,
- const char *func)
+ xfs_failaddr_t func)
{
xfs_alert(bp->b_mount,
-"metadata I/O error in \"%s\" at daddr 0x%llx len %d error %d",
+"metadata I/O error in \"%pS\" at daddr 0x%llx len %d error %d",
func, (uint64_t)XFS_BUF_ADDR(bp), bp->b_length,
-bp->b_error);
}
projects / linux.git / blobdiff