The xfs_spaceman utility previously failed to account for AGFL blocks.
Old output (Before changes).
$ sudo xfs_spaceman -c "freesp" /media/xfs
from to extents blocks pct
1024 2047 1 1262 0.04
4096 8191 1 5126 0.15
8192 16383 3 35344 1.05
32768 65535 1 43989 1.31
262144 524287 3 1334894 39.78
524288 967428 2 1934840 57.66
As you can see the AGFL blocks were unaccounted (4 per AG, and there
were 4 AGs in this filesystem).
This patch is concerned with adding a new function which will walk the free
extents in AGFL and account for these AGFL blocks, while file system scanning.
New output (After implementing this patch).
$ uname -a
Linux dhruv-MacBookAir 3.18.0-rc7+ #3 SMP Thu Dec 25 15:29:59 IST 2014 x86_64
x86_64 x86_64 GNU/Linux
$ sudo xfs_spaceman -V
xfs_spaceman version 3.2.2
$ sudo xfs_spaceman -c "freesp" /media/xfs
from to extents blocks pct
1 1 16 16 0.00
1024 2047 1 1262 0.04
4096 8191 1 5126 0.15
8192 16383 3 35344 1.05
32768 65535 1 43989 1.31
262144 524287 3 1334894 39.78
524288 967428 2 1934840 57.66
-------------------------------------------------------------------------------------------
Signed-off-by: Dhruvesh Rathore <dhruvesh_r@xxxxxxxxxxx>
Signed-off-by: Amey Ruikar <ameyruikar@xxxxxxxxx>
Signed-off-by: Somdeep Dey <somdeepdey10@xxxxxxxxx>
---
fs/xfs/libxfs/xfs_alloc.c | 53 ++++++++++++++
1 file changed, 53 insertions(+)
--- a/fs/xfs/libxfs/xfs_alloc.c 2015-01-28 15:25:02.396172903 +0530
+++ b/fs/xfs/libxfs/xfs_alloc.c 2015-01-28 15:13:46.936198272 +0530
@@ -2697,6 +2697,56 @@
}
+/*
+ * When we map free space we need to take into account the blocks
+ * that are indexed by the AGFL. They aren't found by walking the
+ * free space btrees, so we have to walk each AGFL to find them.
+ */
+static int
+xfs_alloc_agfl_freespace_map(
+ struct xfs_mount *mp,
+ struct xfs_agf *agf,
+ struct fiemap_extent_info *fieinfo,
+ xfs_agnumber_t agno)
+{
+ xfs_buf_t *agflbp;
+ __be32 *agfl_bno;
+ int i;
+ int error = 0;
+
+ error = xfs_alloc_read_agfl(mp, NULL, be32_to_cpu(agf->agf_seqno),
&agflbp);
+
+ if (error)
+ return error;
+
+ agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
+
+ for(i = be32_to_cpu(agf->agf_flfirst);
+ i <= be32_to_cpu(agf->agf_fllast);) {
+
+ xfs_daddr_t dbno;
+ xfs_fileoff_t dlen;
+ int flags = 0;
+
+ /*
+ * Use daddr format for all range/len calculations as that is
+ * the format the range/len variables are supplied in by
+ * userspace.
+ */
+
+ dbno = XFS_AGB_TO_DADDR(mp, agno, be32_to_cpu(agfl_bno[i]));
+ dlen = XFS_FSB_TO_BB(mp, 1);
+
+ error = -fiemap_fill_next_extent(fieinfo,BBTOB(dbno),
+ BBTOB(dbno), BBTOB(dlen),
flags);
+ if (error)
+ break;
+ if (++i == XFS_AGFL_SIZE(mp))
+ i = 0;
+ }
+ xfs_buf_relse(agflbp);
+ return error;
+}
/*
* Map the freespace from the requested range in the requested order.
@@ -2803,6 +2853,9 @@
}
XFS_WANT_CORRUPTED_GOTO(i == 1, del_cursor);
+ /* Account for the free blocks in AGFL */
+ error = xfs_alloc_agfl_freespace_map(mp, XFS_BUF_TO_AGF(agbp),
fieinfo, agno);
+
if (!bycnt) {
/*
* if we are doing a bno ordered lookup, we can just
-------------------------------------------------------------------------------------------
|