[53/58] xfs: teach fiemap about reflink'd extents

Commit Message

Darrick J. Wong Oct. 7, 2015, 5 a.m. UTC

Teach FIEMAP to report shared (i.e. reflinked) extents.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 fs/xfs/xfs_bmap_util.c |    2 +-
 fs/xfs/xfs_bmap_util.h |    3 ++
 fs/xfs/xfs_ioctl.c     |   12 ++++++++-
 fs/xfs/xfs_iops.c      |   62 +++++++++++++++++++++++++++++++++++++++---------
 4 files changed, 63 insertions(+), 16 deletions(-)



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Patch

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index b20d136..f161db1 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -698,7 +698,7 @@  xfs_getbmap(
 		int full = 0;	/* user array is full */
 
 		/* format results & advance arg */
-		error = formatter(&arg, &out[i], &full);
+		error = formatter(ip, &arg, &out[i], &full);
 		if (error || full)
 			break;
 	}
diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index af97d9a..d0dc504 100644
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -37,7 +37,8 @@  int	xfs_bmap_punch_delalloc_range(struct xfs_inode *ip,
 		xfs_fileoff_t start_fsb, xfs_fileoff_t length);
 
 /* bmap to userspace formatter - copy to user & advance pointer */
-typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);
+typedef int (*xfs_bmap_format_t)(struct xfs_inode *, void **, struct getbmapx *,
+		int *);
 int	xfs_getbmap(struct xfs_inode *ip, struct getbmapx *bmv,
 		xfs_bmap_format_t formatter, void *arg);
 
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 50ea19e..92aaca0 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1352,7 +1352,11 @@  out_drop_write:
 }
 
 STATIC int
-xfs_getbmap_format(void **ap, struct getbmapx *bmv, int *full)
+xfs_getbmap_format(
+	struct xfs_inode	*ip,
+	void			**ap,
+	struct getbmapx		*bmv,
+	int			*full)
 {
 	struct getbmap __user	*base = (struct getbmap __user *)*ap;
 
@@ -1396,7 +1400,11 @@  xfs_ioc_getbmap(
 }
 
 STATIC int
-xfs_getbmapx_format(void **ap, struct getbmapx *bmv, int *full)
+xfs_getbmapx_format(
+	struct xfs_inode	*ip,
+	void			**ap,
+	struct getbmapx		*bmv,
+	int			*full)
 {
 	struct getbmapx __user	*base = (struct getbmapx __user *)*ap;
 
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 8294132..5eeed1b 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -38,6 +38,8 @@ 
 #include "xfs_dir2.h"
 #include "xfs_trans_space.h"
 #include "xfs_pnfs.h"
+#include "xfs_bit.h"
+#include "xfs_reflink.h"
 
 #include <linux/capability.h>
 #include <linux/xattr.h>
@@ -1014,14 +1016,21 @@  xfs_vn_update_time(
  */
 STATIC int
 xfs_fiemap_format(
+	struct xfs_inode	*ip,
 	void			**arg,
 	struct getbmapx		*bmv,
 	int			*full)
 {
-	int			error;
+	int			error = 0;
 	struct fiemap_extent_info *fieinfo = *arg;
 	u32			fiemap_flags = 0;
-	u64			logical, physical, length;
+	u64			logical, physical, length, loop_len, len;
+	xfs_extlen_t		elen;
+	xfs_nlink_t		nr;
+	xfs_fsblock_t		fsbno;
+	xfs_agnumber_t		agno;
+	xfs_agblock_t		agbno;
+	struct xfs_mount	*mp = ip->i_mount;
 
 	/* Do nothing for a hole */
 	if (bmv->bmv_block == -1LL)
@@ -1029,7 +1038,7 @@  xfs_fiemap_format(
 
 	logical = BBTOB(bmv->bmv_offset);
 	physical = BBTOB(bmv->bmv_block);
-	length = BBTOB(bmv->bmv_length);
+	length = loop_len = BBTOB(bmv->bmv_length);
 
 	if (bmv->bmv_oflags & BMV_OF_PREALLOC)
 		fiemap_flags |= FIEMAP_EXTENT_UNWRITTEN;
@@ -1038,16 +1047,45 @@  xfs_fiemap_format(
 				 FIEMAP_EXTENT_UNKNOWN);
 		physical = 0;   /* no block yet */
 	}
-	if (bmv->bmv_oflags & BMV_OF_LAST)
-		fiemap_flags |= FIEMAP_EXTENT_LAST;
-
-	error = fiemap_fill_next_extent(fieinfo, logical, physical,
-					length, fiemap_flags);
-	if (error > 0) {
-		error = 0;
-		*full = 1;	/* user array now full */
-	}
 
+	while (loop_len > 0) {
+		u32 ext_flags = 0;
+
+		if (bmv->bmv_oflags & BMV_OF_DELALLOC) {
+			physical = 0;
+			len = loop_len;
+			nr = 1;
+		} else if (xfs_is_reflink_inode(ip)) {
+			fsbno = XFS_DADDR_TO_FSB(mp, BTOBB(physical));
+			agno = XFS_FSB_TO_AGNO(mp, fsbno);
+			agbno = XFS_FSB_TO_AGBNO(mp, fsbno);
+			error = xfs_reflink_get_refcount(mp, agno, agbno,
+					&elen, &nr);
+			if (error)
+				goto out;
+			len = XFS_FSB_TO_B(mp, elen);
+			if (len == 0 || len > loop_len)
+				len = loop_len;
+			if (nr >= 2)
+				ext_flags |= FIEMAP_EXTENT_SHARED;
+		} else
+			len = loop_len;
+		if ((bmv->bmv_oflags & BMV_OF_LAST) &&
+		    len == loop_len)
+			ext_flags |= FIEMAP_EXTENT_LAST;
+
+		error = fiemap_fill_next_extent(fieinfo, logical, physical,
+						len, fiemap_flags | ext_flags);
+		if (error > 0) {
+			error = 0;
+			*full = 1;	/* user array now full */
+			goto out;
+		}
+		logical += len;
+		physical += len;
+		loop_len -= len;
+	}
+out:
 	return error;
 }