> On Fri, Jan 02, 2015 at 06:40:33PM +0900, Namjae Jeon wrote: > > FALLOC_FL_INSERT_RANGE command is the opposite command of > > FALLOC_FL_COLLAPSE_RANGE that is needed for advertisers or someone who want 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. and this command also has same limitation as FALLOC_FL_COLLAPSE_RANGE, > > that is block boundary and use ftruncate(2) for crosses EOF. > > > > Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> > > Signed-off-by: Ashish Sangwan <a.sangwan@xxxxxxxxxxx> > > --- > > fs/open.c | 8 +++++++- > > include/uapi/linux/falloc.h | 15 +++++++++++++++ > > 2 files changed, 22 insertions(+), 1 deletion(-) > > > > diff --git a/fs/open.c b/fs/open.c > > index 36662d0..74ed498 100644 > > --- a/fs/open.c > > +++ b/fs/open.c > > @@ -232,7 +232,8 @@ int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len) > > > > /* 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)) > > + FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | > > + FALLOC_FL_INSERT_RANGE)) > > return -EOPNOTSUPP; > > > > /* Punch hole and zero range are mutually exclusive */ > > @@ -250,6 +251,11 @@ int do_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/uapi/linux/falloc.h b/include/uapi/linux/falloc.h > > index d1197ae..1f20723 100644 > > --- a/include/uapi/linux/falloc.h > > +++ b/include/uapi/linux/falloc.h > > @@ -41,4 +41,19 @@ > > */ > > #define FALLOC_FL_ZERO_RANGE 0x10 > > > > +/* > > + * FALLOC_FL_INSERT_RANGE is use to insert space within the file size without > > used > > > + * 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. > > I suppose we should split this comment up into a few paragraphs similar > to the collapse range comment it is based on. That means we split > here... > > > + * 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. > > ... and here. > > Otherwise this looks fine to me. Okay, I will fix them. > > Brian > > > + * 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_ */ > > -- > > 1.7.11-rc0 > > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
