xfs: fix freeing speculative preallocations for preallocated files

xfs_can_free_eofblocks returns false for files that have persistent
preallocations unless the force flag is passed and there are delayed
blocks.  This means it won't free delalloc reservations for files
with persistent preallocations unless the force flag is set, and it
will also free the persistent preallocations if the force flag is
set and the file happens to have delayed allocations.

Both of these are bad, so do away with the force flag and always free
only post-EOF delayed allocations for files with the XFS_DIFLAG_PREALLOC
or APPEND flags set.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index ac2e77ebb54c735c07c170f3434e50be8e8d73da..a4d9fbc21b8343eefe4570b6403d6d1a947190d5 100644 (file)
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -486,13 +486,11 @@ out_unlock:
 
 /*
  * Test whether it is appropriate to check an inode for and free post EOF
- * blocks. The 'force' parameter determines whether we should also consider
- * regular files that are marked preallocated or append-only.
+ * blocks.
  */
 bool
 xfs_can_free_eofblocks(
-       struct xfs_inode        *ip,
-       bool                    force)
+       struct xfs_inode        *ip)
 {
        struct xfs_bmbt_irec    imap;
        struct xfs_mount        *mp = ip->i_mount;
@@ -526,11 +524,11 @@ xfs_can_free_eofblocks(
                return false;
 
        /*
-        * Do not free real preallocated or append-only files unless the file
-        * has delalloc blocks and we are forced to remove them.
+        * Only free real extents for inodes with persistent preallocations or
+        * the append-only flag.
         */
        if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
-               if (!force || ip->i_delayed_blks == 0)
+               if (ip->i_delayed_blks == 0)
                        return false;
 
        /*
@@ -584,6 +582,22 @@ xfs_free_eofblocks(
        /* Wait on dio to ensure i_size has settled. */
        inode_dio_wait(VFS_I(ip));
 
+       /*
+        * For preallocated files only free delayed allocations.
+        *
+        * Note that this means we also leave speculative preallocations in
+        * place for preallocated files.
+        */
+       if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) {
+               if (ip->i_delayed_blks) {
+                       xfs_bmap_punch_delalloc_range(ip,
+                               round_up(XFS_ISIZE(ip), mp->m_sb.sb_blocksize),
+                               LLONG_MAX);
+               }
+               xfs_inode_clear_eofblocks_tag(ip);
+               return 0;
+       }
+
        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
        if (error) {
                ASSERT(xfs_is_shutdown(mp));
@@ -891,7 +905,7 @@ xfs_prepare_shift(
         * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
         * into the accessible region of the file.
         */
-       if (xfs_can_free_eofblocks(ip, true)) {
+       if (xfs_can_free_eofblocks(ip)) {
                error = xfs_free_eofblocks(ip);
                if (error)
                        return error;

diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index 51f84d8ff372fa704c0f0ffc7681bb61786f6b97..eb0895bfb9dae44ef8a38e6ccea9e5b3928efab0 100644 (file)
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -63,7 +63,7 @@ int   xfs_insert_file_space(struct xfs_inode *, xfs_off_t offset,
                                xfs_off_t len);
 
 /* EOF block manipulation functions */
-bool   xfs_can_free_eofblocks(struct xfs_inode *ip, bool force);
+bool   xfs_can_free_eofblocks(struct xfs_inode *ip);
 int    xfs_free_eofblocks(struct xfs_inode *ip);
 
 int    xfs_swap_extents(struct xfs_inode *ip, struct xfs_inode *tip,

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 0953163a2d8492ee86a1f22df07dae2ae887f5d8..9967334ea99f1a77b3d58b5d061c1b8b539f163d 100644 (file)
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1155,7 +1155,7 @@ xfs_inode_free_eofblocks(
        }
        *lockflags |= XFS_IOLOCK_EXCL;
 
-       if (xfs_can_free_eofblocks(ip, false))
+       if (xfs_can_free_eofblocks(ip))
                return xfs_free_eofblocks(ip);
 
        /* inode could be preallocated or append-only */

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index f36091e1e7f50bedeb6eb1dd2540643da1801f4e..38f946e3be2da3605e9f088dd2919103294bf5f0 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1595,7 +1595,7 @@ xfs_release(
        if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL))
                return 0;
 
-       if (xfs_can_free_eofblocks(ip, false)) {
+       if (xfs_can_free_eofblocks(ip)) {
                /*
                 * Check if the inode is being opened, written and closed
                 * frequently and we have delayed allocation blocks outstanding
@@ -1856,15 +1856,13 @@ xfs_inode_needs_inactive(
 
        /*
         * This file isn't being freed, so check if there are post-eof blocks
-        * to free.  @force is true because we are evicting an inode from the
-        * cache.  Post-eof blocks must be freed, lest we end up with broken
-        * free space accounting.
+        * to free.
         *
         * Note: don't bother with iolock here since lockdep complains about
         * acquiring it in reclaim context. We have the only reference to the
         * inode at this point anyways.
         */
-       return xfs_can_free_eofblocks(ip, true);
+       return xfs_can_free_eofblocks(ip);
 }
 
 /*
@@ -1947,15 +1945,11 @@ xfs_inactive(
 
        if (VFS_I(ip)->i_nlink != 0) {
                /*
-                * force is true because we are evicting an inode from the
-                * cache. Post-eof blocks must be freed, lest we end up with
-                * broken free space accounting.
-                *
                 * Note: don't bother with iolock here since lockdep complains
                 * about acquiring it in reclaim context. We have the only
                 * reference to the inode at this point anyways.
                 */
-               if (xfs_can_free_eofblocks(ip, true))
+               if (xfs_can_free_eofblocks(ip))
                        error = xfs_free_eofblocks(ip);
 
                goto out;