[PATCH V7 12/14] xfs: Compute bmap extent alignments in a separate function

Chandan Babu R
2020-10-19T06:41:47Z

This commit moves over the code which computes stripe alignment and
extent size hint alignment into a separate function. Apart from
xfs_bmap_btalloc(), the new function will be used by another function
introduced in a future commit.

Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
---
fs/xfs/libxfs/xfs_bmap.c | 88 +++++++++++++++++++++++-----------------
1 file changed, 51 insertions(+), 37 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 64c4d0e384a5..935f2d506748 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3463,13 +3463,58 @@ xfs_bmap_btalloc_accounting(
args->len);
}

+static void
+xfs_bmap_compute_alignments(
+ struct xfs_bmalloca *ap,
+ struct xfs_alloc_arg *args,
+ int *stripe_align)
+{
+ struct xfs_mount *mp = args->mp;
+ xfs_extlen_t align = 0; /* minimum allocation alignment */
+ int error;
+
+ /* stripe alignment for allocation is determined by mount parameters */
+ *stripe_align = 0;
+ if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
+ *stripe_align = mp->m_swidth;
+ else if (mp->m_dalign)
+ *stripe_align = mp->m_dalign;
+
+ if (ap->flags & XFS_BMAPI_COWFORK)
+ align = xfs_get_cowextsz_hint(ap->ip);
+ else if (ap->datatype & XFS_ALLOC_USERDATA)
+ align = xfs_get_extsz_hint(ap->ip);
+ if (align) {
+ error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
+ align, 0, ap->eof, 0, ap->conv,
+ &ap->offset, &ap->length);
+ ASSERT(!error);
+ ASSERT(ap->length);
+ }
+
+ /* apply extent size hints if obtained earlier */
+ if (align) {
+ args->prod = align;
+ div_u64_rem(ap->offset, args->prod, &args->mod);
+ if (args->mod)
+ args->mod = args->prod - args->mod;
+ } else if (mp->m_sb.sb_blocksize >= PAGE_SIZE) {
+ args->prod = 1;
+ args->mod = 0;
+ } else {
+ args->prod = PAGE_SIZE >> mp->m_sb.sb_blocklog;
+ div_u64_rem(ap->offset, args->prod, &args->mod);
+ if (args->mod)
+ args->mod = args->prod - args->mod;
+ }
+}
+
STATIC int
xfs_bmap_btalloc(
struct xfs_bmalloca *ap) /* bmap alloc argument struct */
{
xfs_mount_t *mp; /* mount point structure */
xfs_alloctype_t atype = 0; /* type for allocation routines */
- xfs_extlen_t align = 0; /* minimum allocation alignment */
xfs_agnumber_t fb_agno; /* ag number of ap->firstblock */
xfs_agnumber_t ag;
xfs_alloc_arg_t args;
@@ -3489,25 +3534,11 @@ xfs_bmap_btalloc(

mp = ap->ip->i_mount;

- /* stripe alignment for allocation is determined by mount parameters */
- stripe_align = 0;
- if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
- stripe_align = mp->m_swidth;
- else if (mp->m_dalign)
- stripe_align = mp->m_dalign;
-
- if (ap->flags & XFS_BMAPI_COWFORK)
- align = xfs_get_cowextsz_hint(ap->ip);
- else if (ap->datatype & XFS_ALLOC_USERDATA)
- align = xfs_get_extsz_hint(ap->ip);
- if (align) {
- error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
- align, 0, ap->eof, 0, ap->conv,
- &ap->offset, &ap->length);
- ASSERT(!error);
- ASSERT(ap->length);
- }
+ memset(&args, 0, sizeof(args));
+ args.tp = ap->tp;
+ args.mp = mp;

+ xfs_bmap_compute_alignments(ap, &args, &stripe_align);

nullfb = ap->tp->t_firstblock == NULLFSBLOCK;
fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp,
@@ -3538,9 +3569,6 @@ xfs_bmap_btalloc(
* Normal allocation, done through xfs_alloc_vextent.
*/
tryagain = isaligned = 0;
- memset(&args, 0, sizeof(args));
- args.tp = ap->tp;
- args.mp = mp;
args.fsbno = ap->blkno;
args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;

@@ -3571,21 +3599,7 @@ xfs_bmap_btalloc(
args.total = ap->total;
args.minlen = ap->minlen;
}
- /* apply extent size hints if obtained earlier */
- if (align) {
- args.prod = align;
- div_u64_rem(ap->offset, args.prod, &args.mod);
- if (args.mod)
- args.mod = args.prod - args.mod;
- } else if (mp->m_sb.sb_blocksize >= PAGE_SIZE) {
- args.prod = 1;
- args.mod = 0;
- } else {
- args.prod = PAGE_SIZE >> mp->m_sb.sb_blocklog;
- div_u64_rem(ap->offset, args.prod, &args.mod);
- if (args.mod)
- args.mod = args.prod - args.mod;
- }
+
/*
* If we are not low on available data blocks, and the underlying
* logical volume manager is a stripe, and the file offset is zero then
--
2.28.0