[PATCH 4/5] xfs: simplify the fallocate path

Christoph Hellwig
2013-10-12T07:56:42Z

[-- Attachment #1: xfs-simplify-fallocate --]
[-- Type: text/plain, Size: 5785 bytes --]

Call xfs_alloc_file_space or xfs_free_file_space directly from
xfs_file_fallocate instead of going through xfs_change_file_space.

This simplified the code by removing the unessecary marshalling of the
arguments into an xfs_flock64_t structure and allows removing checks that
are already done in the VFS code.

Signed-off-by: Christoph Hellwig <hch@lst.de>

---
fs/xfs/xfs_bmap_util.c | 39 ++-----------------------
fs/xfs/xfs_bmap_util.h | 4 ++
fs/xfs/xfs_file.c | 76 ++++++++++++++++++++++++++++++-------------------
3 files changed, 56 insertions(+), 63 deletions(-)

Index: xfs/fs/xfs/xfs_file.c
===================================================================
--- xfs.orig/fs/xfs/xfs_file.c 2013-10-01 21:06:23.000000000 +0200
+++ xfs/fs/xfs/xfs_file.c 2013-10-01 21:12:47.552218689 +0200
@@ -805,44 +805,64 @@ out:

STATIC long
xfs_file_fallocate(
- struct file *file,
- int mode,
- loff_t offset,
- loff_t len)
+ struct file *file,
+ int mode,
+ loff_t offset,
+ loff_t len)
{
- struct inode *inode = file_inode(file);
- long error;
- loff_t new_size = 0;
- xfs_flock64_t bf;
- xfs_inode_t *ip = XFS_I(inode);
- int cmd = XFS_IOC_RESVSP;
- int attr_flags = 0;
+ struct inode *inode = file_inode(file);
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_trans *tp;
+ long error;
+ loff_t new_size = 0;

+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
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) {
+ error = xfs_free_file_space(ip, offset, len);
+ if (error)
+ goto out_unlock;
+ } else {
+ 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;
+ }

- 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);
+ error = xfs_alloc_file_space(ip, offset, len,
+ XFS_BMAPI_PREALLOC);
if (error)
goto out_unlock;
}

- if (file->f_flags & O_DSYNC)
- attr_flags |= XFS_ATTR_SYNC;
+ tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
+ error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
+ if (error) {
+ xfs_trans_cancel(tp, 0);
+ goto out_unlock;
+ }
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+ ip->i_d.di_mode &= ~S_ISUID;
+ if (ip->i_d.di_mode & S_IXGRP)
+ ip->i_d.di_mode &= ~S_ISGID;
+
+ if (!(mode & FALLOC_FL_PUNCH_HOLE))
+ ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;

- error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags);
+ xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ if (file->f_flags & O_DSYNC)
+ xfs_trans_set_sync(tp);
+ error = xfs_trans_commit(tp, 0);
if (error)
goto out_unlock;

@@ -852,12 +872,12 @@ xfs_file_fallocate(

iattr.ia_valid = ATTR_SIZE;
iattr.ia_size = new_size;
- error = -xfs_setattr_size(ip, &iattr);
+ error = xfs_setattr_size(ip, &iattr);
}

out_unlock:
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
- return error;
+ return -error;
}

Index: xfs/fs/xfs/xfs_bmap_util.c
===================================================================
--- xfs.orig/fs/xfs/xfs_bmap_util.c 2013-10-01 21:06:23.000000000 +0200
+++ xfs/fs/xfs/xfs_bmap_util.c 2013-10-01 21:08:25.264212455 +0200
@@ -965,28 +965,9 @@ xfs_free_eofblocks(
return error;
}

-/*
- * xfs_alloc_file_space()
- * This routine allocates disk space for the given file.
- *
- * If alloc_type == 0, this request is for an ALLOCSP type
- * request which will change the file size. In this case, no
- * DMAPI event will be generated by the call. A TRUNCATE event
- * will be generated later by xfs_setattr.
- *
- * If alloc_type != 0, this request is for a RESVSP type
- * request, and a DMAPI DM_EVENT_WRITE will be generated if the
- * lower block boundary byte address is less than the file's
- * length.
- *
- * RETURNS:
- * 0 on success
- * errno on error
- *
- */
-STATIC int
+int
xfs_alloc_file_space(
- xfs_inode_t *ip,
+ struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len,
int alloc_type)
@@ -1231,21 +1212,9 @@ xfs_zero_remaining_bytes(
return error;
}

-/*
- * xfs_free_file_space()
- * This routine frees disk space for the given file.
- *
- * This routine is only called by xfs_change_file_space
- * for an UNRESVSP type call.
- *
- * RETURNS:
- * 0 on success
- * errno on error
- *
- */
-STATIC int
+int
xfs_free_file_space(
- xfs_inode_t *ip,
+ struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
Index: xfs/fs/xfs/xfs_bmap_util.h
===================================================================
--- xfs.orig/fs/xfs/xfs_bmap_util.h 2013-08-13 15:21:06.000000000 +0200
+++ xfs/fs/xfs/xfs_bmap_util.h 2013-10-01 21:09:13.964213613 +0200
@@ -96,6 +96,10 @@ int xfs_bmap_last_extent(struct xfs_tran
int xfs_change_file_space(struct xfs_inode *ip, int cmd,
xfs_flock64_t *bf, xfs_off_t offset,
int attr_flags);
+int xfs_alloc_file_space(struct xfs_inode *ip, xfs_off_t offset,
+ xfs_off_t len, int alloc_type);
+int xfs_free_file_space(struct xfs_inode *ip, xfs_off_t offset,
+ xfs_off_t len);

/* EOF block manipulation functions */
bool xfs_can_free_eofblocks(struct xfs_inode *ip, bool force);