Commit dd46c787 authored by Namjae Jeon's avatar Namjae Jeon Committed by Dave Chinner
Browse files

fs: Add support FALLOC_FL_INSERT_RANGE for fallocate 



FALLOC_FL_INSERT_RANGE command is the opposite command of
FALLOC_FL_COLLAPSE_RANGE that is needed for someone who wants to add
some data in the middle of file.

FALLOC_FL_INSERT_RANGE will create space for writing new data within
a file after shifting extents to right as given length. This command
also has same limitations as FALLOC_FL_COLLAPSE_RANGE in that
operations need to be filesystem block boundary aligned and cannot
cross the current EOF.

Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarAshish Sangwan <a.sangwan@samsung.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 444a7022

fs/open.c

+6 −2
Original line number Diff line number Diff line
@@ -231,8 +231,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 
		return -EINVAL;



	/* Return error if mode is not supported */

	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |

		     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))

	if (mode & ~FALLOC_FL_SUPPORTED_MASK)

		return -EOPNOTSUPP;



	/* Punch hole and zero range are mutually exclusive */
@@ -250,6 +249,11 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 
	    (mode & ~FALLOC_FL_COLLAPSE_RANGE))

		return -EINVAL;



	/* Insert range should only be used exclusively. */

	if ((mode & FALLOC_FL_INSERT_RANGE) &&

	    (mode & ~FALLOC_FL_INSERT_RANGE))

		return -EINVAL;



	if (!(file->f_mode & FMODE_WRITE))

		return -EBADF;

include/linux/falloc.h

+6 −0
Original line number Diff line number Diff line
@@ -21,4 +21,10 @@ struct space_resv { 
#define FS_IOC_RESVSP		_IOW('X', 40, struct space_resv)

#define FS_IOC_RESVSP64		_IOW('X', 42, struct space_resv)



#define	FALLOC_FL_SUPPORTED_MASK	(FALLOC_FL_KEEP_SIZE |		\

					 FALLOC_FL_PUNCH_HOLE |		\

					 FALLOC_FL_COLLAPSE_RANGE |	\

					 FALLOC_FL_ZERO_RANGE |		\

					 FALLOC_FL_INSERT_RANGE)



#endif /* _FALLOC_H_ */

include/uapi/linux/falloc.h

+17 −0
Original line number Diff line number Diff line
@@ -41,4 +41,21 @@ 
 */

#define FALLOC_FL_ZERO_RANGE		0x10



/*

 * FALLOC_FL_INSERT_RANGE is use to insert space within the file size without

 * overwriting any existing data. The contents of the file beyond offset are

 * shifted towards right by len bytes to create a hole.  As such, this

 * operation will increase the size of the file by len bytes.

 *

 * Different filesystems may implement different limitations on the granularity

 * of the operation. Most will limit operations to filesystem block size

 * boundaries, but this boundary may be larger or smaller depending on

 * the filesystem and/or the configuration of the filesystem or file.

 *

 * Attempting to insert space using this flag at OR beyond the end of

 * the file is considered an illegal operation - just use ftruncate(2) or

 * fallocate(2) with mode 0 for such type of operations.

 */

#define FALLOC_FL_INSERT_RANGE		0x20



#endif /* _UAPI_FALLOC_H_ */

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