xfs: only reclaim unwritten COW extents periodically

We only want to reclaim preallocations from our periodic work item.
Currently this is archived by looking for a dirty inode, but that check
is rather fragile.  Instead add a flag to xfs_reflink_cancel_cow_* so
that the caller can ask for just cancelling unwritten extents in the COW
fork.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix typos in commit message]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index bf65a9ea864293d48e5326178336680c2eb29758..aa8a6f0d09c3b6fabb3847b6b920a558f1789bd6 100644 (file)
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -293,7 +293,7 @@ xfs_end_io(
                        goto done;
                if (ioend->io_bio->bi_error) {
                        error = xfs_reflink_cancel_cow_range(ip,
-                                       ioend->io_offset, ioend->io_size);
+                                       ioend->io_offset, ioend->io_size, true);
                        goto done;
                }
                error = xfs_reflink_end_cow(ip, ioend->io_offset,

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 7234b9748c36e048b15b376e4408ef3626422cf4..3531f8f72fa5e10b83f0fa8bd37afc560b2dbf0a 100644 (file)
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1608,7 +1608,7 @@ xfs_inode_free_cowblocks(
        xfs_ilock(ip, XFS_IOLOCK_EXCL);
        xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
 
-       ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
+       ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
 
        xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
        xfs_iunlock(ip, XFS_IOLOCK_EXCL);

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index edfa6a55b0646d0d444ea0b2c12e46a62a2c4474..7eaf1ef74e3c63ebb3c640e32d2db87864984a4a 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1615,7 +1615,7 @@ xfs_itruncate_extents(
 
        /* Remove all pending CoW reservations. */
        error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
-                       last_block);
+                       last_block, true);
        if (error)
                goto out;
 

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index da6d08fb359c8efdf42a53e283bb030780b5b064..4a84c5ea266d8f8fcec61aa55776fec339d27aaf 100644 (file)
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -548,14 +548,18 @@ xfs_reflink_trim_irec_to_next_cow(
 }
 
 /*
- * Cancel all pending CoW reservations for some block range of an inode.
+ * Cancel CoW reservations for some block range of an inode.
+ *
+ * If cancel_real is true this function cancels all COW fork extents for the
+ * inode; if cancel_real is false, real extents are not cleared.
  */
 int
 xfs_reflink_cancel_cow_blocks(
        struct xfs_inode                *ip,
        struct xfs_trans                **tpp,
        xfs_fileoff_t                   offset_fsb,
-       xfs_fileoff_t                   end_fsb)
+       xfs_fileoff_t                   end_fsb,
+       bool                            cancel_real)
 {
        struct xfs_ifork                *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
        struct xfs_bmbt_irec            got, del;
@@ -579,7 +583,7 @@ xfs_reflink_cancel_cow_blocks(
                                        &idx, &got, &del);
                        if (error)
                                break;
-               } else {
+               } else if (del.br_state == XFS_EXT_UNWRITTEN || cancel_real) {
                        xfs_trans_ijoin(*tpp, ip, 0);
                        xfs_defer_init(&dfops, &firstfsb);
 
@@ -621,13 +625,17 @@ xfs_reflink_cancel_cow_blocks(
 }
 
 /*
- * Cancel all pending CoW reservations for some byte range of an inode.
+ * Cancel CoW reservations for some byte range of an inode.
+ *
+ * If cancel_real is true this function cancels all COW fork extents for the
+ * inode; if cancel_real is false, real extents are not cleared.
  */
 int
 xfs_reflink_cancel_cow_range(
        struct xfs_inode        *ip,
        xfs_off_t               offset,
-       xfs_off_t               count)
+       xfs_off_t               count,
+       bool                    cancel_real)
 {
        struct xfs_trans        *tp;
        xfs_fileoff_t           offset_fsb;
@@ -653,7 +661,8 @@ xfs_reflink_cancel_cow_range(
        xfs_trans_ijoin(tp, ip, 0);
 
        /* Scrape out the old CoW reservations */
-       error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb);
+       error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
+                       cancel_real);
        if (error)
                goto out_cancel;
 
@@ -1450,7 +1459,7 @@ xfs_reflink_clear_inode_flag(
         * We didn't find any shared blocks so turn off the reflink flag.
         * First, get rid of any leftover CoW mappings.
         */
-       error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF);
+       error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, true);
        if (error)
                return error;
 

diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 33ac9b8db68380185ad80073b1890cc70e4e3b09..d29a7967f0290ecb8b4ca7c4d4077723262c8ba2 100644 (file)
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -39,9 +39,9 @@ extern void xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
 
 extern int xfs_reflink_cancel_cow_blocks(struct xfs_inode *ip,
                struct xfs_trans **tpp, xfs_fileoff_t offset_fsb,
-               xfs_fileoff_t end_fsb);
+               xfs_fileoff_t end_fsb, bool cancel_real);
 extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset,
-               xfs_off_t count);
+               xfs_off_t count, bool cancel_real);
 extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
                xfs_off_t count);
 extern int xfs_reflink_recover_cow(struct xfs_mount *mp);

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 890862f2447c193f374b4de64c58940521b203fb..685c042a120f16a8a9a8dad69d8ee7ce6f9274a0 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -953,7 +953,7 @@ xfs_fs_destroy_inode(
        XFS_STATS_INC(ip->i_mount, vn_remove);
 
        if (xfs_is_reflink_inode(ip)) {
-               error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
+               error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, true);
                if (error && !XFS_FORCED_SHUTDOWN(ip->i_mount))
                        xfs_warn(ip->i_mount,
 "Error %d while evicting CoW blocks for inode %llu.",