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>
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index ef51eb43e..a55c1b4 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -37,6 +37,7 @@
#include "xfs_trace.h"
#include <linux/dcache.h>
+#include <linux/falloc.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -882,6 +883,60 @@
return ret;
}
+STATIC long
+xfs_file_fallocate(
+ struct file *file,
+ int mode,
+ loff_t offset,
+ loff_t len)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ long error;
+ loff_t new_size = 0;
+ xfs_flock64_t bf;
+ xfs_inode_t *ip = XFS_I(inode);
+ int cmd = XFS_IOC_RESVSP;
+
+ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+ return -EOPNOTSUPP;
+
+ bf.l_whence = 0;
+ bf.l_start = offset;
+ bf.l_len = len;
+
+ xfs_ilock(ip, XFS_IOLOCK_EXCL);
+
+ if (mode & FALLOC_FL_PUNCH_HOLE)
+ cmd = XFS_IOC_UNRESVSP;
+
+ /* check the new inode size is valid before allocating */
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ offset + len > i_size_read(inode)) {
+ new_size = offset + len;
+ error = inode_newsize_ok(inode, new_size);
+ if (error)
+ goto out_unlock;
+ }
+
+ error = -xfs_change_file_space(ip, cmd, &bf, 0, XFS_ATTR_NOLOCK);
+ if (error)
+ goto out_unlock;
+
+ /* Change file size if needed */
+ if (new_size) {
+ struct iattr iattr;
+
+ iattr.ia_valid = ATTR_SIZE;
+ iattr.ia_size = new_size;
+ error = -xfs_setattr(ip, &iattr, XFS_ATTR_NOLOCK);
+ }
+
+out_unlock:
+ xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+ return error;
+}
+
+
STATIC int
xfs_file_open(
struct inode *inode,
@@ -1000,6 +1055,7 @@
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
+ .fallocate = xfs_file_fallocate,
};
const struct file_operations xfs_dir_file_operations = {