fallocate should be a file operation

Currently all filesystems except XFS implement fallocate asynchronously,
while XFS forced a commit.  Both of these are suboptimal - in case of O_SYNC
I/O we really want our allocation on disk, especially for the !KEEP_SIZE
case where we actually grow the file with user-visible zeroes.  On the
other hand always commiting the transaction is a bad idea for fast-path
uses of fallocate like for example in recent Samba versions.   Given
that block allocation is a data plane operation anyway change it from
an inode operation to a file operation so that we have the file structure
available that lets us check for O_SYNC.

This also includes moving the code around for a few of the filesystems,
and remove the already unnedded S_ISDIR checks given that we only wire
up fallocate for regular files.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index bb003dc9ffff..2e8322c8aa88 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -210,6 +210,7 @@ const struct file_operations ext4_file_operations = {
         .fsync          = ext4_sync_file,
         .splice_read    = generic_file_splice_read,
         .splice_write   = generic_file_splice_write,
+        .fallocate      = ext4_fallocate,
 };
 
 const struct inode_operations ext4_file_inode_operations = {
@@ -223,7 +224,6 @@ const struct inode_operations ext4_file_inode_operations = {
         .removexattr    = generic_removexattr,
 #endif
         .check_acl      = ext4_check_acl,
-        .fallocate      = ext4_fallocate,
         .fiemap         = ext4_fiemap,
 };