In xfs_reflink_end_cow, we erroneously reserve only enough blocks to
handle adding 1 extent. This is problematic if we fragment free space,
have to do CoW, and then have to perform multiple bmap btree expansions.
Furthermore, the BUI recovery routine doesn't reserve /any/ blocks to
handle btree splits, so log recovery fails after our first error causes
the filesystem to go down.
Therefore, refactor the transaction block reservation macros until we
have a macro that works for our deferred (re)mapping activities, and fix
both problems by using that macro.
With 1k blocks we can hit this fairly often in g/187 if the scratch fs
is big enough.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
v2: avoid 64-bit division when calculating block reservation
---
fs/xfs/libxfs/xfs_trans_space.h | 18 ++++++++++++------
fs/xfs/xfs_bmap_item.c | 7 ++++++-
fs/xfs/xfs_reflink.c | 12 ++++++++++--
3 files changed, 28 insertions(+), 9 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_trans_space.h b/fs/xfs/libxfs/xfs_trans_space.h
index 7917f6e..04278cf 100644
--- a/fs/xfs/libxfs/xfs_trans_space.h
+++ b/fs/xfs/libxfs/xfs_trans_space.h
@@ -23,6 +23,16 @@
*/
#define XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp) \
(((mp)->m_rmap_mxr[0]) - ((mp)->m_rmap_mnr[0]))
+static inline unsigned int
+XFS_RMAPADD_SPACE_RES(
+ struct xfs_mount *mp)
+{
+ return xfs_sb_version_hasrmapbt(&mp->m_sb) ? mp->m_rmap_maxlevels : 0;
+}
+#define XFS_NRMAPADD_SPACE_RES(mp,b,w)\
+ (((b + XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp) - 1) / \
+ XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp)) * \
+ XFS_RMAPADD_SPACE_RES(mp))
#define XFS_MAX_CONTIG_EXTENTS_PER_BLOCK(mp) \
(((mp)->m_alloc_mxr[0]) - ((mp)->m_alloc_mnr[0]))
#define XFS_EXTENTADD_SPACE_RES(mp,w) (XFS_BM_MAXLEVELS(mp,w) - 1)
@@ -31,12 +41,8 @@
XFS_MAX_CONTIG_EXTENTS_PER_BLOCK(mp)) * \
XFS_EXTENTADD_SPACE_RES(mp,w))
#define XFS_SWAP_RMAP_SPACE_RES(mp,b,w)\
- (((b + XFS_MAX_CONTIG_EXTENTS_PER_BLOCK(mp) - 1) / \
- XFS_MAX_CONTIG_EXTENTS_PER_BLOCK(mp)) * \
- XFS_EXTENTADD_SPACE_RES(mp,w) + \
- ((b + XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp) - 1) / \
- XFS_MAX_CONTIG_RMAPS_PER_BLOCK(mp)) * \
- (mp)->m_rmap_maxlevels)
+ (XFS_NEXTENTADD_SPACE_RES((mp), (b), (w)) + \
+ XFS_NRMAPADD_SPACE_RES((mp), (b), (w)))
#define XFS_DAENTER_1B(mp,w) \
((w) == XFS_DATA_FORK ? (mp)->m_dir_geo->fsbcount : 1)
#define XFS_DAENTER_DBS(mp,w) \
diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
index 9bf57c7..055ab8f 100644
--- a/fs/xfs/xfs_bmap_item.c
+++ b/fs/xfs/xfs_bmap_item.c
@@ -34,6 +34,8 @@
#include "xfs_bmap.h"
#include "xfs_icache.h"
#include "xfs_trace.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_trans_space.h"
kmem_zone_t *xfs_bui_zone;
@@ -402,6 +404,7 @@ xfs_bui_recover(
struct xfs_inode *ip = NULL;
struct xfs_defer_ops dfops;
xfs_fsblock_t firstfsb;
+ unsigned int resblks;
ASSERT(!test_bit(XFS_BUI_RECOVERED, &buip->bui_flags));
@@ -446,7 +449,9 @@ xfs_bui_recover(
return -EIO;
}
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
+ resblks = XFS_SWAP_RMAP_SPACE_RES(mp, 1, XFS_DATA_FORK);
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, resblks, 0,
+ 0, &tp);
if (error)
return error;
budp = xfs_trans_get_bud(tp, buip);
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index c0f3754..9b159f8 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -705,8 +705,16 @@ xfs_reflink_end_cow(
offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count);
- /* Start a rolling transaction to switch the mappings */
- resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK);
+ /*
+ * Start a rolling transaction to switch the mappings. We're
+ * unlikely ever to have to remap 16T worth of single-block
+ * extents, so just cap the worst case extent count to 2^32-1.
+ * Stick a warning in just in case.
+ */
+ WARN_ON(end_fsb - offset_fsb + 1 > ~0U);
+ resblks = min_t(xfs_fileoff_t, ~0U, end_fsb - offset_fsb + 1);
+ resblks = XFS_SWAP_RMAP_SPACE_RES(ip->i_mount, resblks,
+ XFS_DATA_FORK);
error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write,
resblks, 0, 0, &tp);
if (error)
--
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