diff mbox series

[6/6] xfs: refactor xfs_file_fallocate

Message ID 20240821063108.650126-7-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [1/6] block: remove checks for FALLOC_FL_NO_HIDE_STALE | expand

Commit Message

Christoph Hellwig Aug. 21, 2024, 6:30 a.m. UTC
Refactor xfs_file_fallocate into separate helpers for each mode,
two factors for i_size handling and a single switch statement over the
supported modes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_file.c | 327 +++++++++++++++++++++++++++++-----------------
 1 file changed, 205 insertions(+), 122 deletions(-)

Comments

Brian Foster Aug. 21, 2024, 12:44 p.m. UTC | #1
On Wed, Aug 21, 2024 at 08:30:32AM +0200, Christoph Hellwig wrote:
> Refactor xfs_file_fallocate into separate helpers for each mode,
> two factors for i_size handling and a single switch statement over the
> supported modes.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_file.c | 327 +++++++++++++++++++++++++++++-----------------
>  1 file changed, 205 insertions(+), 122 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 489bc1b173c268..9d3bac7731bdcb 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -852,6 +852,189 @@ static inline bool xfs_file_sync_writes(struct file *filp)
>  	return false;
>  }
>  
...
> +
> +static int
> +xfs_falloc_unshare_range(
> +	struct file		*file,
> +	int			mode,
> +	loff_t			offset,
> +	loff_t			len)
> +{
> +	struct inode		*inode = file_inode(file);
> +	loff_t			new_size = 0;
> +	int			error;
> +
> +	error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
> +	if (error)
> +		return error;
> +
> +	error = xfs_reflink_unshare(XFS_I(inode), offset, len);
> +	if (error)
> +		return error;
> +

Doesn't unshare imply alloc?

> +	return xfs_falloc_setsize(file, new_size);
> +}
> +
...
> @@ -894,129 +1075,31 @@ xfs_file_fallocate(
>  	if (error)
>  		goto out_unlock;
>  
> -	if (mode & FALLOC_FL_PUNCH_HOLE) {
> +	switch (mode & FALLOC_FL_MODE_MASK) {
> +	case FALLOC_FL_PUNCH_HOLE:
>  		error = xfs_free_file_space(ip, offset, len);
...
> +		break;
> +	case FALLOC_FL_COLLAPSE_RANGE:
> +		error = xfs_falloc_collapse_range(file, offset, len);
> +		break;
> +	case FALLOC_FL_INSERT_RANGE:
> +		error = xfs_falloc_insert_range(file, offset, len);
> +		break;
> +	case FALLOC_FL_ZERO_RANGE:
> +		error = xfs_falloc_zero_range(file, mode, offset, len);
> +		break;
> +	case FALLOC_FL_UNSHARE_RANGE:
> +		error = xfs_falloc_unshare_range(file, mode, offset, len);
> +		break;
> +	case FALLOC_FL_ALLOCATE_RANGE:
> +		error = xfs_falloc_allocate_range(file, mode, offset, len);
> +		break;
> +	default:
> +		error = -EOPNOTSUPP;
> +		break;
>  	}
>  
> -	if (xfs_file_sync_writes(file))
> +	if (!error && xfs_file_sync_writes(file))
>  		error = xfs_log_force_inode(ip);

I'd think if you hit -ENOSPC or something after doing a partial alloc to
a sync inode, you'd still want to flush the changes that were made..?

Brian

>  
>  out_unlock:
> -- 
> 2.43.0
> 
>
Christoph Hellwig Aug. 21, 2024, 12:57 p.m. UTC | #2
On Wed, Aug 21, 2024 at 08:44:31AM -0400, Brian Foster wrote:
> > +	error = xfs_reflink_unshare(XFS_I(inode), offset, len);
> > +	if (error)
> > +		return error;
> > +
> 
> Doesn't unshare imply alloc?

Yes, ooks like that got lost and no test noticed it

> > -	if (xfs_file_sync_writes(file))
> > +	if (!error && xfs_file_sync_writes(file))
> >  		error = xfs_log_force_inode(ip);
> 
> I'd think if you hit -ENOSPC or something after doing a partial alloc to
> a sync inode, you'd still want to flush the changes that were made..?

Persistence behavior on error is always undefined.  And that's also
what the current code does, as it jumps past the log force from all
error exits.
Brian Foster Aug. 21, 2024, 1:09 p.m. UTC | #3
On Wed, Aug 21, 2024 at 02:57:56PM +0200, Christoph Hellwig wrote:
> On Wed, Aug 21, 2024 at 08:44:31AM -0400, Brian Foster wrote:
> > > +	error = xfs_reflink_unshare(XFS_I(inode), offset, len);
> > > +	if (error)
> > > +		return error;
> > > +
> > 
> > Doesn't unshare imply alloc?
> 
> Yes, ooks like that got lost and no test noticed it
> 
> > > -	if (xfs_file_sync_writes(file))
> > > +	if (!error && xfs_file_sync_writes(file))
> > >  		error = xfs_log_force_inode(ip);
> > 
> > I'd think if you hit -ENOSPC or something after doing a partial alloc to
> > a sync inode, you'd still want to flush the changes that were made..?
> 
> Persistence behavior on error is always undefined.  And that's also
> what the current code does, as it jumps past the log force from all
> error exits.
> 

Ok, if this preserves existing behavior then I'm not too worried about
it. Thanks.

Brian
diff mbox series

Patch

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 489bc1b173c268..9d3bac7731bdcb 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -852,6 +852,189 @@  static inline bool xfs_file_sync_writes(struct file *filp)
 	return false;
 }
 
+static int
+xfs_falloc_newsize(
+	struct file		*file,
+	int			mode,
+	loff_t			offset,
+	loff_t			len,
+	loff_t			*new_size)
+{
+	struct inode		*inode = file_inode(file);
+
+	if ((mode & FALLOC_FL_KEEP_SIZE) || offset + len <= i_size_read(inode))
+		return 0;
+	*new_size = offset + len;
+	return inode_newsize_ok(inode, *new_size);
+}
+
+static int
+xfs_falloc_setsize(
+	struct file		*file,
+	loff_t			new_size)
+{
+	struct iattr iattr = {
+		.ia_valid	= ATTR_SIZE,
+		.ia_size	= new_size,
+	};
+
+	if (!new_size)
+		return 0;
+	return xfs_vn_setattr_size(file_mnt_idmap(file), file_dentry(file),
+			&iattr);
+}
+
+static int
+xfs_falloc_collapse_range(
+	struct file		*file,
+	loff_t			offset,
+	loff_t			len)
+{
+	struct inode		*inode = file_inode(file);
+	loff_t			new_size = i_size_read(inode) - len;
+	int			error;
+
+	if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len))
+		return -EINVAL;
+
+	/*
+	 * There is no need to overlap collapse range with EOF, in which case it
+	 * is effectively a truncate operation
+	 */
+	if (offset + len >= i_size_read(inode))
+		return -EINVAL;
+
+	error = xfs_collapse_file_space(XFS_I(inode), offset, len);
+	if (error)
+		return error;
+	return xfs_falloc_setsize(file, new_size);
+}
+
+static int
+xfs_falloc_insert_range(
+	struct file		*file,
+	loff_t			offset,
+	loff_t			len)
+{
+	struct inode		*inode = file_inode(file);
+	loff_t			isize = i_size_read(inode);
+	int			error;
+
+	if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len))
+		return -EINVAL;
+
+	/*
+	 * New inode size must not exceed ->s_maxbytes, accounting for
+	 * possible signed overflow.
+	 */
+	if (inode->i_sb->s_maxbytes - isize < len)
+		return -EFBIG;
+
+	/* Offset should be less than i_size */
+	if (offset >= isize)
+		return -EINVAL;
+
+	error = xfs_falloc_setsize(file, isize + len);
+	if (error)
+		return error;
+
+	/*
+	 * Perform hole insertion now that the file size has been updated so
+	 * that if we crash during the operation we don't leave shifted extents
+	 * past EOF and hence losing access to the data that is contained within
+	 * them.
+	 */
+	return xfs_insert_file_space(XFS_I(inode), offset, len);
+}
+
+/*
+ * Punch a hole and prealloc the range.  We use a hole punch rather than
+ * unwritten extent conversion for two reasons:
+ *
+ *   1.) Hole punch handles partial block zeroing for us.
+ *   2.) If prealloc returns ENOSPC, the file range is still zero-valued by
+ *	 virtue of the hole punch.
+ */
+static int
+xfs_falloc_zero_range(
+	struct file		*file,
+	int			mode,
+	loff_t			offset,
+	loff_t			len)
+{
+	struct inode		*inode = file_inode(file);
+	unsigned int		blksize = i_blocksize(inode);
+	loff_t			new_size = 0;
+	int			error;
+
+	trace_xfs_zero_file_space(XFS_I(inode));
+
+	error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
+	if (error)
+		return error;
+
+	error = xfs_free_file_space(XFS_I(inode), offset, len);
+	if (error)
+		return error;
+
+	len = round_up(offset + len, blksize) - round_down(offset, blksize);
+	offset = round_down(offset, blksize);
+	error = xfs_alloc_file_space(XFS_I(inode), offset, len);
+	if (error)
+		return error;
+	return xfs_falloc_setsize(file, new_size);
+}
+
+static int
+xfs_falloc_unshare_range(
+	struct file		*file,
+	int			mode,
+	loff_t			offset,
+	loff_t			len)
+{
+	struct inode		*inode = file_inode(file);
+	loff_t			new_size = 0;
+	int			error;
+
+	error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
+	if (error)
+		return error;
+
+	error = xfs_reflink_unshare(XFS_I(inode), offset, len);
+	if (error)
+		return error;
+
+	return xfs_falloc_setsize(file, new_size);
+}
+
+static int
+xfs_falloc_allocate_range(
+	struct file		*file,
+	int			mode,
+	loff_t			offset,
+	loff_t			len)
+{
+	struct inode		*inode = file_inode(file);
+	loff_t			new_size = 0;
+	int			error;
+
+	/*
+	 * If always_cow mode we can't use preallocations and thus should not
+	 * create them.
+	 */
+	if (xfs_is_always_cow_inode(XFS_I(inode)))
+		return -EOPNOTSUPP;
+
+	error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
+	if (error)
+		return error;
+
+	error = xfs_alloc_file_space(XFS_I(inode), offset, len);
+	if (error)
+		return error;
+	return xfs_falloc_setsize(file, new_size);
+}
+
 #define	XFS_FALLOC_FL_SUPPORTED						\
 		(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |		\
 		 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |	\
@@ -868,8 +1051,6 @@  xfs_file_fallocate(
 	struct xfs_inode	*ip = XFS_I(inode);
 	long			error;
 	uint			iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
-	loff_t			new_size = 0;
-	bool			do_file_insert = false;
 
 	if (!S_ISREG(inode->i_mode))
 		return -EINVAL;
@@ -894,129 +1075,31 @@  xfs_file_fallocate(
 	if (error)
 		goto out_unlock;
 
-	if (mode & FALLOC_FL_PUNCH_HOLE) {
+	switch (mode & FALLOC_FL_MODE_MASK) {
+	case FALLOC_FL_PUNCH_HOLE:
 		error = xfs_free_file_space(ip, offset, len);
-		if (error)
-			goto out_unlock;
-	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
-		if (!xfs_is_falloc_aligned(ip, offset, len)) {
-			error = -EINVAL;
-			goto out_unlock;
-		}
-
-		/*
-		 * There is no need to overlap collapse range with EOF,
-		 * in which case it is effectively a truncate operation
-		 */
-		if (offset + len >= i_size_read(inode)) {
-			error = -EINVAL;
-			goto out_unlock;
-		}
-
-		new_size = i_size_read(inode) - len;
-
-		error = xfs_collapse_file_space(ip, offset, len);
-		if (error)
-			goto out_unlock;
-	} else if (mode & FALLOC_FL_INSERT_RANGE) {
-		loff_t		isize = i_size_read(inode);
-
-		if (!xfs_is_falloc_aligned(ip, offset, len)) {
-			error = -EINVAL;
-			goto out_unlock;
-		}
-
-		/*
-		 * New inode size must not exceed ->s_maxbytes, accounting for
-		 * possible signed overflow.
-		 */
-		if (inode->i_sb->s_maxbytes - isize < len) {
-			error = -EFBIG;
-			goto out_unlock;
-		}
-		new_size = isize + len;
-
-		/* Offset should be less than i_size */
-		if (offset >= isize) {
-			error = -EINVAL;
-			goto out_unlock;
-		}
-		do_file_insert = true;
-	} 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_ZERO_RANGE) {
-			/*
-			 * Punch a hole and prealloc the range.  We use a hole
-			 * punch rather than unwritten extent conversion for two
-			 * reasons:
-			 *
-			 *   1.) Hole punch handles partial block zeroing for us.
-			 *   2.) If prealloc returns ENOSPC, the file range is
-			 *       still zero-valued by virtue of the hole punch.
-			 */
-			unsigned int blksize = i_blocksize(inode);
-
-			trace_xfs_zero_file_space(ip);
-
-			error = xfs_free_file_space(ip, offset, len);
-			if (error)
-				goto out_unlock;
-
-			len = round_up(offset + len, blksize) -
-			      round_down(offset, blksize);
-			offset = round_down(offset, blksize);
-		} else if (mode & FALLOC_FL_UNSHARE_RANGE) {
-			error = xfs_reflink_unshare(ip, offset, len);
-			if (error)
-				goto out_unlock;
-		} else {
-			/*
-			 * If always_cow mode we can't use preallocations and
-			 * thus should not create them.
-			 */
-			if (xfs_is_always_cow_inode(ip)) {
-				error = -EOPNOTSUPP;
-				goto out_unlock;
-			}
-		}
-
-		error = xfs_alloc_file_space(ip, offset, len);
-		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_vn_setattr_size(file_mnt_idmap(file),
-					    file_dentry(file), &iattr);
-		if (error)
-			goto out_unlock;
-	}
-
-	/*
-	 * Perform hole insertion now that the file size has been
-	 * updated so that if we crash during the operation we don't
-	 * leave shifted extents past EOF and hence losing access to
-	 * the data that is contained within them.
-	 */
-	if (do_file_insert) {
-		error = xfs_insert_file_space(ip, offset, len);
-		if (error)
-			goto out_unlock;
+		break;
+	case FALLOC_FL_COLLAPSE_RANGE:
+		error = xfs_falloc_collapse_range(file, offset, len);
+		break;
+	case FALLOC_FL_INSERT_RANGE:
+		error = xfs_falloc_insert_range(file, offset, len);
+		break;
+	case FALLOC_FL_ZERO_RANGE:
+		error = xfs_falloc_zero_range(file, mode, offset, len);
+		break;
+	case FALLOC_FL_UNSHARE_RANGE:
+		error = xfs_falloc_unshare_range(file, mode, offset, len);
+		break;
+	case FALLOC_FL_ALLOCATE_RANGE:
+		error = xfs_falloc_allocate_range(file, mode, offset, len);
+		break;
+	default:
+		error = -EOPNOTSUPP;
+		break;
 	}
 
-	if (xfs_file_sync_writes(file))
+	if (!error && xfs_file_sync_writes(file))
 		error = xfs_log_force_inode(ip);
 
 out_unlock: