xfs: pass post-eof speculative prealloc blocks to bmapi
authorBrian Foster <bfoster@redhat.com>
Mon, 28 Nov 2016 03:57:42 +0000 (14:57 +1100)
committerDave Chinner <david@fromorbit.com>
Mon, 28 Nov 2016 03:57:42 +0000 (14:57 +1100)
xfs_file_iomap_begin_delay() implements post-eof speculative
preallocation by extending the block count of the requested delayed
allocation. Now that xfs_bmapi_reserve_delalloc() has been updated to
handle prealloc blocks separately and tag the inode, update
xfs_file_iomap_begin_delay() to use the new parameter and rely on the
former to tag the inode.

Note that this patch does not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
fs/xfs/xfs_iomap.c

index e4bfde212cc2874b4f8b546ce7555b2d8ea40530..15a83813b7085ad281ee713be05262abe107fa3e 100644 (file)
@@ -536,10 +536,11 @@ xfs_file_iomap_begin_delay(
        xfs_fileoff_t           offset_fsb = XFS_B_TO_FSBT(mp, offset);
        xfs_fileoff_t           maxbytes_fsb =
                XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
-       xfs_fileoff_t           end_fsb, orig_end_fsb;
+       xfs_fileoff_t           end_fsb;
        int                     error = 0, eof = 0;
        struct xfs_bmbt_irec    got;
        xfs_extnum_t            idx;
+       xfs_fsblock_t           prealloc_blocks = 0;
 
        ASSERT(!XFS_IS_REALTIME_INODE(ip));
        ASSERT(!xfs_get_extsz_hint(ip));
@@ -594,33 +595,32 @@ xfs_file_iomap_begin_delay(
         * the lower level functions are updated.
         */
        count = min_t(loff_t, count, 1024 * PAGE_SIZE);
-       end_fsb = orig_end_fsb =
-               min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
+       end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
 
        if (eof) {
-               xfs_fsblock_t   prealloc_blocks;
-
                prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, idx);
                if (prealloc_blocks) {
                        xfs_extlen_t    align;
                        xfs_off_t       end_offset;
+                       xfs_fileoff_t   p_end_fsb;
 
                        end_offset = XFS_WRITEIO_ALIGN(mp, offset + count - 1);
-                       end_fsb = XFS_B_TO_FSBT(mp, end_offset) +
-                               prealloc_blocks;
+                       p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) +
+                                       prealloc_blocks;
 
                        align = xfs_eof_alignment(ip, 0);
                        if (align)
-                               end_fsb = roundup_64(end_fsb, align);
+                               p_end_fsb = roundup_64(p_end_fsb, align);
 
-                       end_fsb = min(end_fsb, maxbytes_fsb);
-                       ASSERT(end_fsb > offset_fsb);
+                       p_end_fsb = min(p_end_fsb, maxbytes_fsb);
+                       ASSERT(p_end_fsb > offset_fsb);
+                       prealloc_blocks = p_end_fsb - end_fsb;
                }
        }
 
 retry:
        error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb,
-                       end_fsb - offset_fsb, 0, &got, &idx, eof);
+                       end_fsb - offset_fsb, prealloc_blocks, &got, &idx, eof);
        switch (error) {
        case 0:
                break;
@@ -628,8 +628,8 @@ retry:
        case -EDQUOT:
                /* retry without any preallocation */
                trace_xfs_delalloc_enospc(ip, offset, count);
-               if (end_fsb != orig_end_fsb) {
-                       end_fsb = orig_end_fsb;
+               if (prealloc_blocks) {
+                       prealloc_blocks = 0;
                        goto retry;
                }
                /*FALLTHRU*/
@@ -637,13 +637,6 @@ retry:
                goto out_unlock;
        }
 
-       /*
-        * Tag the inode as speculatively preallocated so we can reclaim this
-        * space on demand, if necessary.
-        */
-       if (end_fsb != orig_end_fsb)
-               xfs_inode_set_eofblocks_tag(ip);
-
        trace_xfs_iomap_alloc(ip, offset, count, 0, &got);
 done:
        if (isnullstartblock(got.br_startblock))