diff mbox

[RESEND,1/12] fs: Add support FALLOC_FL_INSERT_RANGE for fallocate

Message ID 1424101680-3301-2-git-send-email-linkinjeon@gmail.com
State Superseded, archived
Headers show

Commit Message

Namjae Jeon Feb. 16, 2015, 3:47 p.m. UTC
From: Namjae Jeon <namjae.jeon@samsung.com>

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@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Cc: Brian Foster<bfoster@redhat.com>
---
 fs/open.c                   |    8 +++++++-
 include/uapi/linux/falloc.h |   17 +++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

Comments

Dave Chinner Feb. 16, 2015, 11:53 p.m. UTC | #1
On Tue, Feb 17, 2015 at 12:47:48AM +0900, Namjae Jeon wrote:
> From: Namjae Jeon <namjae.jeon@samsung.com>
> 
> 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@samsung.com>
> Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
> Cc: Brian Foster<bfoster@redhat.com>
> ---
>  fs/open.c                   |    8 +++++++-
>  include/uapi/linux/falloc.h |   17 +++++++++++++++++
>  2 files changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/open.c b/fs/open.c
> index 813be03..762fb45 100644
> --- a/fs/open.c
> +++ b/fs/open.c
> @@ -232,7 +232,8 @@ int vfs_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;

Can we create a FALLOC_FL_SUPPORTED_MASK define in falloc.h
so that we only need to add new flags to the mask in rather than
change this code every time we add a new flag?

Cheers,

Dave.
Namjae Jeon Feb. 17, 2015, 1:49 a.m. UTC | #2
> On Tue, Feb 17, 2015 at 12:47:48AM +0900, Namjae Jeon wrote:
> > From: Namjae Jeon <namjae.jeon@samsung.com>
> >
> > 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@samsung.com>
> > Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
> > Cc: Brian Foster<bfoster@redhat.com>
> > ---
> >  fs/open.c                   |    8 +++++++-
> >  include/uapi/linux/falloc.h |   17 +++++++++++++++++
> >  2 files changed, 24 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/open.c b/fs/open.c
> > index 813be03..762fb45 100644
> > --- a/fs/open.c
> > +++ b/fs/open.c
> > @@ -232,7 +232,8 @@ int vfs_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;
> 
> Can we create a FALLOC_FL_SUPPORTED_MASK define in falloc.h
> so that we only need to add new flags to the mask in rather than
> change this code every time we add a new flag?
Sure, I will do it. and share the patch with the others you gave me review points soon.

Thanks for review!
> 
> Cheers,
> 
> Dave.
> --
> Dave Chinner
> david@fromorbit.com

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diff mbox

Patch

diff --git a/fs/open.c b/fs/open.c
index 813be03..762fb45 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -232,7 +232,8 @@  int vfs_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 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/uapi/linux/falloc.h b/include/uapi/linux/falloc.h
index d1197ae..3e445a7 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_ */