From 0a6eab8bd4e0120d49511acbb294797d96ef9e4a Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 3 Oct 2016 09:11:13 -0700 Subject: vfs: support FS_XFLAG_COWEXTSIZE and get/set of CoW extent size hint Introduce XFLAGs for the new XFS CoW extent size hint, and actually plumb the CoW extent size hint into the fsxattr structure. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- include/uapi/linux/fs.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 3b00f7c8943f..cf398764b19e 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -157,7 +157,8 @@ struct fsxattr { __u32 fsx_extsize; /* extsize field value (get/set)*/ __u32 fsx_nextents; /* nextents field value (get) */ __u32 fsx_projid; /* project identifier (get/set) */ - unsigned char fsx_pad[12]; + __u32 fsx_cowextsize; /* CoW extsize field value (get/set)*/ + unsigned char fsx_pad[8]; }; /* @@ -178,6 +179,7 @@ struct fsxattr { #define FS_XFLAG_NODEFRAG 0x00002000 /* do not defragment */ #define FS_XFLAG_FILESTREAM 0x00004000 /* use filestream allocator */ #define FS_XFLAG_DAX 0x00008000 /* use DAX for IO */ +#define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */ #define FS_XFLAG_HASATTR 0x80000000 /* no DIFLAG for this */ /* the read-only stuff doesn't really belong here, but any other place is -- cgit v1.2.3 From 71be6b4942dd64bc17728f82f787be98fd8afed7 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 3 Oct 2016 09:11:14 -0700 Subject: vfs: add a FALLOC_FL_UNSHARE mode to fallocate to unshare a range of blocks Add a new fallocate mode flag that explicitly unshares blocks on filesystems that support such features. The new flag can only be used with an allocate-mode fallocate call. Signed-off-by: Darrick J. Wong --- fs/open.c | 5 +++++ include/linux/falloc.h | 3 ++- include/uapi/linux/falloc.h | 18 ++++++++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/fs/open.c b/fs/open.c index 4fd6e256f4f4..d58525dda28d 100644 --- a/fs/open.c +++ b/fs/open.c @@ -256,6 +256,11 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) (mode & ~FALLOC_FL_INSERT_RANGE)) return -EINVAL; + /* Unshare range should only be used with allocate mode. */ + if ((mode & FALLOC_FL_UNSHARE_RANGE) && + (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) + return -EINVAL; + if (!(file->f_mode & FMODE_WRITE)) return -EBADF; diff --git a/include/linux/falloc.h b/include/linux/falloc.h index 996111000a8c..7494dc67c66f 100644 --- a/include/linux/falloc.h +++ b/include/linux/falloc.h @@ -25,6 +25,7 @@ struct space_resv { FALLOC_FL_PUNCH_HOLE | \ FALLOC_FL_COLLAPSE_RANGE | \ FALLOC_FL_ZERO_RANGE | \ - FALLOC_FL_INSERT_RANGE) + FALLOC_FL_INSERT_RANGE | \ + FALLOC_FL_UNSHARE_RANGE) #endif /* _FALLOC_H_ */ diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h index 3e445a760f14..b075f601919b 100644 --- a/include/uapi/linux/falloc.h +++ b/include/uapi/linux/falloc.h @@ -58,4 +58,22 @@ */ #define FALLOC_FL_INSERT_RANGE 0x20 +/* + * FALLOC_FL_UNSHARE_RANGE is used to unshare shared blocks within the + * file size without overwriting any existing data. The purpose of this + * call is to preemptively reallocate any blocks that are subject to + * copy-on-write. + * + * 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. + * + * This flag can only be used with allocate-mode fallocate, which is + * to say that it cannot be used with the punch, zero, collapse, or + * insert range modes. + */ +#define FALLOC_FL_UNSHARE_RANGE 0x40 + #endif /* _UAPI_FALLOC_H_ */ -- cgit v1.2.3