1 files changed, 17 insertions, 2 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 2e7989e3a2d6..52f96e16694c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -823,7 +823,8 @@ xfs_file_fallocate(
 
         if (!S_ISREG(inode->i_mode))
                 return -EINVAL;
-        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
+                     FALLOC_FL_COLLAPSE_RANGE))
                 return -EOPNOTSUPP;
 
         xfs_ilock(ip, XFS_IOLOCK_EXCL);
@@ -831,6 +832,20 @@ xfs_file_fallocate(
                 error = xfs_free_file_space(ip, offset, len);
                 if (error)
                         goto out_unlock;
+        } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
+                unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
+
+                if (offset & blksize_mask || len & blksize_mask) {
+                        error = -EINVAL;
+                        goto out_unlock;
+                }
+
+                ASSERT(offset + len < i_size_read(inode));
+                new_size = i_size_read(inode) - len;
+
+                error = xfs_collapse_file_space(ip, offset, len);
+                if (error)
+                        goto out_unlock;
         } else {
                 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
                     offset + len > i_size_read(inode)) {
@@ -859,7 +874,7 @@ xfs_file_fallocate(
         if (ip->i_d.di_mode & S_IXGRP)
                 ip->i_d.di_mode &= ~S_ISGID;
 
-        if (!(mode & FALLOC_FL_PUNCH_HOLE))
+        if (!(mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE)))
                 ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
 
         xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);