diff options
| author | Namjae Jeon <namjae.jeon@samsung.com> | 2015-03-25 15:07:05 +1100 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2015-03-25 15:07:05 +1100 |
| commit | dd46c787788d5bf5b974729d43e4c405814a4c7d (patch) | |
| tree | 67ae36b5a9cbbec7b71995417f9350999dca6b9c | |
| parent | 444a702231412e82fb1c09679adc159301e9242c (diff) | |
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: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | fs/open.c | 8 | ||||
| -rw-r--r-- | include/linux/falloc.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/falloc.h | 17 |
3 files changed, 29 insertions, 2 deletions
diff --git a/fs/open.c b/fs/open.c index 33f9cbf2610b..b724cc0e0228 100644 --- a/fs/open.c +++ b/fs/open.c @@ -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; diff --git a/include/linux/falloc.h b/include/linux/falloc.h index 31591686ac2d..996111000a8c 100644 --- a/include/linux/falloc.h +++ b/include/linux/falloc.h @@ -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_ */ diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h index d1197ae3723c..3e445a760f14 100644 --- a/include/uapi/linux/falloc.h +++ b/include/uapi/linux/falloc.h @@ -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_ */ |