[PATCH 11/13] xfs: rework splitting of indirect block reservations

Christoph Hellwig
2024-03-27T11:04:08Z

Move the check if we have enough indirect blocks and the stealing of
the deleted extent blocks out of xfs_bmap_split_indlen and into the
caller to prepare for handling delayed allocation of RT extents that
can't easily be stolen.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/libxfs/xfs_bmap.c | 38 ++++++++++++++++----------------------
1 file changed, 16 insertions(+), 22 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 131d4f063b660a..9d0b7caa9a036c 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4829,31 +4829,17 @@ xfs_bmapi_remap(
* ores == 1). The number of stolen blocks is returned. The availability and
* subsequent accounting of stolen blocks is the responsibility of the caller.
*/
-static xfs_filblks_t
+static void
xfs_bmap_split_indlen(
xfs_filblks_t ores, /* original res. */
xfs_filblks_t *indlen1, /* ext1 worst indlen */
- xfs_filblks_t *indlen2, /* ext2 worst indlen */
- xfs_filblks_t avail) /* stealable blocks */
+ xfs_filblks_t *indlen2) /* ext2 worst indlen */
{
xfs_filblks_t len1 = *indlen1;
xfs_filblks_t len2 = *indlen2;
xfs_filblks_t nres = len1 + len2; /* new total res. */
- xfs_filblks_t stolen = 0;
xfs_filblks_t resfactor;

- /*
- * Steal as many blocks as we can to try and satisfy the worst case
- * indlen for both new extents.
- */
- if (ores < nres && avail)
- stolen = XFS_FILBLKS_MIN(nres - ores, avail);
- ores += stolen;
-
- /* nothing else to do if we've satisfied the new reservation */
- if (ores >= nres)
- return stolen;
-
/*
* We can't meet the total required reservation for the two extents.
* Calculate the percent of the overall shortage between both extents
@@ -4898,8 +4884,6 @@ xfs_bmap_split_indlen(

*indlen1 = len1;
*indlen2 = len2;
-
- return stolen;
}

int
@@ -4915,7 +4899,7 @@ xfs_bmap_del_extent_delay(
struct xfs_bmbt_irec new;
int64_t da_old, da_new, da_diff = 0;
xfs_fileoff_t del_endoff, got_endoff;
- xfs_filblks_t got_indlen, new_indlen, stolen;
+ xfs_filblks_t got_indlen, new_indlen, stolen = 0;
uint32_t state = xfs_bmap_fork_to_state(whichfork);
uint64_t fdblocks;
int error = 0;
@@ -4994,8 +4978,19 @@ xfs_bmap_del_extent_delay(
new_indlen = xfs_bmap_worst_indlen(ip, new.br_blockcount);

WARN_ON_ONCE(!got_indlen || !new_indlen);
- stolen = xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen,
- del->br_blockcount);
+ /*
+ * Steal as many blocks as we can to try and satisfy the worst
+ * case indlen for both new extents.
+ */
+ da_new = got_indlen + new_indlen;
+ if (da_new > da_old) {
+ stolen = XFS_FILBLKS_MIN(da_new - da_old,
+ del->br_blockcount);
+ da_old += stolen;
+ }
+ if (da_new > da_old)
+ xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen);
+ da_new = got_indlen + new_indlen;

got->br_startblock = nullstartblock((int)got_indlen);

@@ -5007,7 +5002,6 @@ xfs_bmap_del_extent_delay(
xfs_iext_next(ifp, icur);
xfs_iext_insert(ip, icur, &new, state);

- da_new = got_indlen + new_indlen - stolen;
del->br_blockcount -= stolen;
break;
}
--
2.39.2