RE: [PATCH v3] manpage: update FALLOC_FL_INSERT_RANGE flag in fallocate

Namjae Jeon
2015-05-08T09:42:31Z

> Hi Namjae,
Hi Michael,

>
> > Update FALLOC_FL_INSERT_RANGE flag in fallocate.
>
> Sorry -- I should have said that I already applied your V2
> patch and made the fix we discussed (and that you add below).
> I just hadn't pushed to Git yet. Done now.
Okay :)
Thanks very much!!
>
> Cheers,
>
> Michael
>
> On 05/08/2015 07:28 AM, Namjae Jeon wrote:
> > Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
> > Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
> > ---
> > man2/fallocate.2 | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
> > 1 file changed, 84 insertions(+), 5 deletions(-)
> >
> > diff --git a/man2/fallocate.2 b/man2/fallocate.2
> > index 0cc1a00..0d31027 100644
> > --- a/man2/fallocate.2
> > +++ b/man2/fallocate.2
> > @@ -228,6 +228,59 @@ ext4, for extent-based files (since Linux 3.15)
> > .IP *
> > SMB3 (since Linux 3.17)
> > .\" commit 30175628bf7f521e9ee31ac98fa6d6fe7441a556
> > +.SS Increasing file space
> > +flag (available since Linux 4.1)
> > +.\" commit dd46c787788d5bf5b974729d43e4c405814a4c7d
> > +Specifying the
> > +.BR FALLOC_FL_INSERT_RANGE
> > +flag in
> > +.I mode
> > +will increase the file space by inserting a hole within the file size without
> > +overwriting any existing data.
> > +The hole will start at
> > +.I offset
> > +and continue for
> > +.I len
> > +bytes.
> > +For inserting hole inside file, the contents of the file starting at
> > +.I offset
> > +will be shifted towards right by
> > +.I len
> > +bytes.
> > +Inserting a hole inside the file will increase the file size by
> > +.I len
> > +bytes.
> > +
> > +This mode has the same limitation as
> > +.BR FALLOC_FL_COLLAPSE_RANGE
> > +regarding the
> > +granularity of the operation.
> > +If the granularity requirements are not met,
> > +.BR fallocate ()
> > +will fail with the error
> > +.BR EINVAL.
> > +If the
> > +.I offset
> > +is greater than or equal to the end of file, an error is
> > +returned.
> > +For such type of operations, i.e. inserting a hole at the end of file,
> > +.BR ftruncate(2)
> > +should be used.
> > +In case
> > +.IR offset + len
> > +exceeds the maximum file size, errno will be set to
> > +.B EFBIG.
> > +
> > +No other flags may be specified in
> > +.IR mode
> > +in conjunction with
> > +.BR FALLOC_FL_INSERT_RANGE .
> > +
> > +As of Linux 4.1,
> > +.B FALLOC_FL_INSERT_RANGE
> > +is supported by
> > +XFS.
> > +.\" commit a904b1ca5751faf5ece8600e18cd3b674afcca1b
> > .SH RETURN VALUE
> > On success,
> > .BR fallocate ()
> > @@ -245,6 +298,12 @@ is not a valid file descriptor, or is not opened for writing.
> > .IR offset + len
> > exceeds the maximum file size.
> > .TP
> > +.B EFBIG
> > +.I mode
> > +is
> > +.BR FALLOC_FL_INSERT_RANGE ,
> > +the current file size+len exceeds the maximum file size.
> > +.TP
> > .B EINTR
> > A signal was caught during execution.
> > .TP
> > @@ -273,7 +332,17 @@ reaches or passes the end of the file.
> > .B EINVAL
> > .I mode
> > is
> > -.BR FALLOC_FL_COLLAPSE_RANGE ,
> > +.BR FALLOC_FL_INSERT_RANGE
> > +and the range specified by
> > +.I offset
> > +reaches or passes the end of the file.
> > +.TP
> > +.B EINVAL
> > +.I mode
> > +is
> > +.BR FALLOC_FL_COLLAPSE_RANGE
> > +or
> > +.BR FALLOC_FL_INSERT_RANGE ,
> > but either
> > .I offset
> > or
> > @@ -282,18 +351,24 @@ is not a multiple of the filesystem block size.
> > .TP
> > .B EINVAL
> > .I mode
> > -contains both
> > +contains either of
> > .B FALLOC_FL_COLLAPSE_RANGE
> > +or
> > +.B FALLOC_FL_INSERT_RANGE
> > and other flags;
> > no other flags are permitted with
> > -.BR FALLOC_FL_COLLAPSE_RANGE .
> > +.BR FALLOC_FL_COLLAPSE_RANGE
> > +or
> > +.BR FALLOC_FL_INSERT_RANGE .
> > .TP
> > .B EINVAL
> > .I mode
> > is
> > .BR FALLOC_FL_COLLAPSE_RANGE
> > or
> > -.BR FALLOC_FL_ZERO_RANGE ,
> > +.BR FALLOC_FL_ZERO_RANGE
> > +or
> > +.BR FALLOC_FL_INSERT_RANGE ,
> > but the file referred to by
> > .I fd
> > is not a regular file.
> > @@ -345,6 +420,8 @@ specifies
> > .BR FALLOC_FL_PUNCH_HOLE
> > or
> > .BR FALLOC_FL_COLLAPSE_RANGE
> > +or
> > +.BR FALLOC_FL_INSERT_RANGE
> > and
> > the file referred to by
> > .I fd
> > @@ -363,7 +440,9 @@ refers to a pipe or FIFO.
> > .B ETXTBSY
> > .I mode
> > specifies
> > -.BR FALLOC_FL_COLLAPSE_RANGE ,
> > +.BR FALLOC_FL_COLLAPSE_RANGE
> > +or
> > +.BR FALLOC_FL_INSERT_RANGE ,
> > but the file referred to by
> > .IR fd
> > is currently being executed.
> >
>
>
> --
> Michael Kerrisk
> Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
> Linux/UNIX System Programming Training: http://man7.org/training/