@@ -3310,12 +3310,12 @@ xfs_bmap_select_minlen(
static int
xfs_bmap_btalloc_select_lengths(
struct xfs_bmalloca *ap,
- struct xfs_alloc_arg *args,
- xfs_extlen_t *blen)
+ struct xfs_alloc_arg *args)
{
struct xfs_mount *mp = args->mp;
struct xfs_perag *pag;
xfs_agnumber_t agno, startag;
+ xfs_extlen_t blen = 0;
int error = 0;
if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
@@ -3329,19 +3329,18 @@ xfs_bmap_btalloc_select_lengths(
if (startag == NULLAGNUMBER)
startag = 0;
- *blen = 0;
for_each_perag_wrap(mp, startag, agno, pag) {
- error = xfs_bmap_longest_free_extent(pag, args->tp, blen);
+ error = xfs_bmap_longest_free_extent(pag, args->tp, &blen);
if (error && error != -EAGAIN)
break;
error = 0;
- if (*blen >= args->maxlen)
+ if (blen >= args->maxlen)
break;
}
if (pag)
xfs_perag_rele(pag);
- args->minlen = xfs_bmap_select_minlen(ap, args, *blen);
+ args->minlen = xfs_bmap_select_minlen(ap, args, blen);
return error;
}
@@ -3551,78 +3550,40 @@ xfs_bmap_exact_minlen_extent_alloc(
* If we are not low on available data blocks and we are allocating at
* EOF, optimise allocation for contiguous file extension and/or stripe
* alignment of the new extent.
- *
- * NOTE: ap->aeof is only set if the allocation length is >= the
- * stripe unit and the allocation offset is at the end of file.
*/
static int
xfs_bmap_btalloc_at_eof(
struct xfs_bmalloca *ap,
- struct xfs_alloc_arg *args,
- xfs_extlen_t blen,
- bool ag_only)
+ struct xfs_alloc_arg *args)
{
struct xfs_mount *mp = args->mp;
struct xfs_perag *caller_pag = args->pag;
+ xfs_extlen_t alignment = args->alignment;
int error;
+ ASSERT(ap->aeof && ap->offset);
+ ASSERT(args->alignment >= 1);
+
/*
- * If there are already extents in the file, try an exact EOF block
- * allocation to extend the file as a contiguous extent. If that fails,
- * or it's the first allocation in a file, just try for a stripe aligned
- * allocation.
+ * Compute the alignment slop for the fallback path so we ensure
+ * we account for the potential alignemnt space required by the
+ * fallback paths before we modify the AGF and AGFL here.
*/
- if (ap->offset) {
- xfs_extlen_t alignment = args->alignment;
-
- /*
- * Compute the alignment slop for the fallback path so we ensure
- * we account for the potential alignment space required by the
- * fallback paths before we modify the AGF and AGFL here.
- */
- args->alignment = 1;
- args->alignslop = alignment - args->alignment;
-
- if (!caller_pag)
- args->pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, ap->blkno));
- error = xfs_alloc_vextent_exact_bno(args, ap->blkno);
- if (!caller_pag) {
- xfs_perag_put(args->pag);
- args->pag = NULL;
- }
- if (error)
- return error;
-
- if (args->fsbno != NULLFSBLOCK)
- return 0;
- /*
- * Exact allocation failed. Reset to try an aligned allocation
- * according to the original allocation specification.
- */
- args->alignment = alignment;
- args->alignslop = 0;
- }
+ args->alignment = 1;
+ args->alignslop = alignment - args->alignment;
- if (ag_only) {
- error = xfs_alloc_vextent_near_bno(args, ap->blkno);
- } else {
+ if (!caller_pag)
+ args->pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, ap->blkno));
+ error = xfs_alloc_vextent_exact_bno(args, ap->blkno);
+ if (!caller_pag) {
+ xfs_perag_put(args->pag);
args->pag = NULL;
- error = xfs_alloc_vextent_start_ag(args, ap->blkno);
- ASSERT(args->pag == NULL);
- args->pag = caller_pag;
}
- if (error)
- return error;
- if (args->fsbno != NULLFSBLOCK)
- return 0;
-
- /*
- * Aligned allocation failed, so all fallback paths from here drop the
- * start alignment requirement as we know it will not succeed.
- */
- args->alignment = 1;
- return 0;
+ /* Reset alignment to original specifications. */
+ args->alignment = alignment;
+ args->alignslop = 0;
+ return error;
}
/*
@@ -3688,12 +3649,19 @@ xfs_bmap_btalloc_filestreams(
}
args->minlen = xfs_bmap_select_minlen(ap, args, blen);
- if (ap->aeof)
- error = xfs_bmap_btalloc_at_eof(ap, args, blen, true);
+ if (ap->aeof && ap->offset)
+ error = xfs_bmap_btalloc_at_eof(ap, args);
+ /* This may be an aligned allocation attempt. */
if (!error && args->fsbno == NULLFSBLOCK)
error = xfs_alloc_vextent_near_bno(args, ap->blkno);
+ /* Attempt non-aligned allocation if we haven't already. */
+ if (!error && args->fsbno == NULLFSBLOCK && args->alignment > 1) {
+ args->alignment = 1;
+ error = xfs_alloc_vextent_near_bno(args, ap->blkno);
+ }
+
out_low_space:
/*
* We are now done with the perag reference for the filestreams
@@ -3715,7 +3683,6 @@ xfs_bmap_btalloc_best_length(
struct xfs_bmalloca *ap,
struct xfs_alloc_arg *args)
{
- xfs_extlen_t blen = 0;
int error;
ap->blkno = XFS_INO_TO_FSB(args->mp, ap->ip->i_ino);
@@ -3726,23 +3693,33 @@ xfs_bmap_btalloc_best_length(
* the request. If one isn't found, then adjust the minimum allocation
* size to the largest space found.
*/
- error = xfs_bmap_btalloc_select_lengths(ap, args, &blen);
+ error = xfs_bmap_btalloc_select_lengths(ap, args);
if (error)
return error;
/*
- * Don't attempt optimal EOF allocation if previous allocations barely
- * succeeded due to being near ENOSPC. It is highly unlikely we'll get
- * optimal or even aligned allocations in this case, so don't waste time
- * trying.
+ * If we are in low space mode, then optimal allocation will fail so
+ * prepare for minimal allocation and run the low space algorithm
+ * immediately.
*/
- if (ap->aeof && !(ap->tp->t_flags & XFS_TRANS_LOWMODE)) {
- error = xfs_bmap_btalloc_at_eof(ap, args, blen, false);
- if (error || args->fsbno != NULLFSBLOCK)
- return error;
+ if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
+ ASSERT(args->fsbno == NULLFSBLOCK);
+ return xfs_bmap_btalloc_low_space(ap, args);
+ }
+
+ if (ap->aeof && ap->offset)
+ error = xfs_bmap_btalloc_at_eof(ap, args);
+
+ /* This may be an aligned allocation attempt. */
+ if (!error && args->fsbno == NULLFSBLOCK)
+ error = xfs_alloc_vextent_start_ag(args, ap->blkno);
+
+ /* Attempt non-aligned allocation if we haven't already. */
+ if (!error && args->fsbno == NULLFSBLOCK && args->alignment > 1) {
+ args->alignment = 1;
+ error = xfs_alloc_vextent_start_ag(args, ap->blkno);
}
- error = xfs_alloc_vextent_start_ag(args, ap->blkno);
if (error || args->fsbno != NULLFSBLOCK)
return error;
@@ -780,7 +780,7 @@ xfs_ialloc_ag_alloc(
* the exact agbno requirement and increase the alignment
* instead. It is critical that the total size of the request
* (len + alignment + slop) does not increase from this point
- * on, so reset minalignslop to ensure it is not included in
+ * on, so reset alignslop to ensure it is not included in
* subsequent requests.
*/
args.alignslop = 0;