Btrfs: Use correct values when updating inode i_size on fallocate

commit d1ea6a61454e7d7ff0873d0ad1ae27d5807da0d3 upstream.

commit f2bc9dd07e3424c4ec5f3949961fe053d47bc825
Author: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Date:   Wed Jan 20 12:57:53 2010 +0530

    Btrfs: Use correct values when updating inode i_size on fallocate

    Even though we allocate more, we should be updating inode i_size
    as per the arguments passed

    Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Acked-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b330e27c2d8b01e3e3b619266936ebd927918297..7563ea0c41804a8712ae113f581eb478d09c03be 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5799,7 +5799,7 @@ out_fail:
 }
 
 static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
-                              u64 alloc_hint, int mode)
+                       u64 alloc_hint, int mode, loff_t actual_len)
 {
        struct btrfs_trans_handle *trans;
        struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -5808,6 +5808,7 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
        u64 cur_offset = start;
        u64 num_bytes = end - start;
        int ret = 0;
+       u64 i_size;
 
        while (num_bytes > 0) {
                alloc_size = min(num_bytes, root->fs_info->max_extent);
@@ -5846,8 +5847,12 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
                BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
                if (!(mode & FALLOC_FL_KEEP_SIZE) &&
                    cur_offset > inode->i_size) {
-                       i_size_write(inode, cur_offset);
-                       btrfs_ordered_update_i_size(inode, cur_offset, NULL);
+                       if (cur_offset > actual_len)
+                               i_size  = actual_len;
+                       else
+                               i_size = cur_offset;
+                       i_size_write(inode, i_size);
+                       btrfs_ordered_update_i_size(inode, i_size, NULL);
                }
 
                ret = btrfs_update_inode(trans, root, inode);
@@ -5940,7 +5945,7 @@ static long btrfs_fallocate(struct inode *inode, int mode,
                     !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
                        ret = prealloc_file_range(inode,
                                                  cur_offset, last_byte,
-                                                 alloc_hint, mode);
+                                               alloc_hint, mode, offset+len);
                        if (ret < 0) {
                                free_extent_map(em);
                                break;