xfs: simplify the fallocate path

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>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

3 files changed, 56 insertions, 63 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index bdd552d83107..7e1c2ae81c35 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -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)
 {
diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index 061260946f7a..77cf5001719b 100644
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -96,6 +96,10 @@ int	xfs_bmap_last_extent(struct xfs_trans *tp, struct xfs_inode *ip,
 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);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 116300f3b1d4..c8a75a75e25a 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -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;
+
+        xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 
-        error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags);
+        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;
 }