[V2,2/2] xfsprogs: Fix log reservation calculation for xattr insert operation
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Message ID 20200115125450.22782-2-chandanrlinux@gmail.com
State New
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Series
  • [V2,1/2] xfsprogs: Pass xattr name and value length explicitly to xfs_attr_leaf_newentsize
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Commit Message

Chandan Rajendra Jan. 15, 2020, 12:54 p.m. UTC
Log space reservation for xattr insert operation can be divided into two
parts,
1. Mount time
   - Inode
   - Superblock for accounting space allocations
   - AGF for accounting space used be count, block number, rmapbt and refcnt
     btrees.

2. The remaining log space can only be calculated at run time because,
   - A local xattr can be large enough to cause a double split of the dabtree.
   - The value of the xattr can be large enough to be stored in remote
     blocks. The contents of the remote blocks are not logged.

   The log space reservation could be,
   - 2 * XFS_DA_NODE_MAXDEPTH number of blocks. Additional XFS_DA_NODE_MAXDEPTH
     number of blocks are required if xattr is large enough to cause another
     split of the dabtree path from root to leaf block.
   - BMBT blocks for storing (2 * XFS_DA_NODE_MAXDEPTH) record
     entries. Additional XFS_DA_NODE_MAXDEPTH number of blocks are required in
     case of a double split of the dabtree path from root to leaf blocks.
   - Space for logging blocks of count, block number, rmap and refcnt btrees.

Presently, mount time log reservation includes block count required for a
single split of the dabtree. The dabtree block count is also taken into
account by xfs_attr_calc_size().

Also, AGF log space reservation isn't accounted for. Hence log reservation
calculation for xattr insert operation gives incorrect value.

Apart from the above, xfs_log_calc_max_attrsetm_res() passes a byte count as
an argument to XFS_NEXTENTADD_SPACE_RES() instead of block count.

To fix these issues, this commit refactors xfs_attr_calc_size() to calculate,
1. The number of dabtree blocks that need to be logged.
2. The number of remote blocks that need to allocated.
3. The number of dabtree blocks that need to allocated.

xfs_attr_set() uses this information to compute
1. Number of blocks that needs to allocated during the transaction.
2. Number of bytes that needs to be reserved in the log.

This commit also modifies xfs_log_calc_max_attrsetm_res() to invoke
xfs_attr_calc_size() to obtain the number of dabtree blocks to be
logged which it uses to figure out the total number of blocks to be logged.

Signed-off-by: Chandan Rajendra <chandanrlinux@gmail.com>
---
Changelog:
V1 -> V2:
1. xfs_attr_calc_size() computes
   - Number of blocks required to log dabtree blocks.
   - Number of remote blocks.
   - Total dabtree blocks to be allocated.
2. Add new function xfs_calc_attr_blocks() to compute the total number of
   blocks to be allocated during xattr insert operation.
3. Add new function xfs_calc_attr_res() to compute the log space to be
   reserved during xattr insert operation.

 libxfs/xfs_attr.c       | 108 +++++++++++++++++++++++++---------------
 libxfs/xfs_attr.h       |   3 ++
 libxfs/xfs_log_rlimit.c |  17 ++++---
 libxfs/xfs_trans_resv.c |  56 +++++++++++----------
 libxfs/xfs_trans_resv.h |   2 +
 5 files changed, 113 insertions(+), 73 deletions(-)

Patch
diff mbox series

diff --git a/libxfs/xfs_attr.c b/libxfs/xfs_attr.c
index 2a0050f4..18b4b1ab 100644
--- a/libxfs/xfs_attr.c
+++ b/libxfs/xfs_attr.c
@@ -182,43 +182,6 @@  xfs_attr_get(
 	return 0;
 }
 
-/*
- * Calculate how many blocks we need for the new attribute,
- */
-STATIC int
-xfs_attr_calc_size(
-	struct xfs_da_args	*args,
-	int			*local)
-{
-	struct xfs_mount	*mp = args->dp->i_mount;
-	int			size;
-	int			nblks;
-
-	/*
-	 * Determine space new attribute will use, and if it would be
-	 * "local" or "remote" (note: local != inline).
-	 */
-	size = xfs_attr_leaf_newentsize(mp, args->namelen, args->valuelen,
-					local);
-	nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
-	if (*local) {
-		if (size > (args->geo->blksize / 2)) {
-			/* Double split possible */
-			nblks *= 2;
-		}
-	} else {
-		/*
-		 * Out of line attribute, cannot double split, but
-		 * make room for the attribute value itself.
-		 */
-		uint	dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
-		nblks += dblocks;
-		nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
-	}
-
-	return nblks;
-}
-
 STATIC int
 xfs_attr_try_sf_addname(
 	struct xfs_inode	*dp,
@@ -247,6 +210,64 @@  xfs_attr_try_sf_addname(
 	return error ? error : error2;
 }
 
+STATIC uint
+xfs_calc_attr_blocks(
+	struct xfs_mount	*mp,
+	unsigned int		total_dablks,
+	unsigned int		rmt_blks)
+{
+	unsigned int bmbt_blks;
+
+	bmbt_blks = XFS_NEXTENTADD_SPACE_RES(mp, total_dablks + rmt_blks,
+					XFS_ATTR_FORK);
+	return total_dablks + rmt_blks + bmbt_blks;
+}
+
+/*
+ * Calculate how many blocks we need for the new attribute,
+ */
+void
+xfs_attr_calc_size(
+	struct xfs_mount	*mp,
+	int			namelen,
+	int			valuelen,
+	int			*local,
+	unsigned int		*log_dablks,
+	unsigned int		*rmt_blks,
+	unsigned int		*total_dablks)
+{
+	unsigned int		blksize;
+	int			size;
+
+	blksize = mp->m_dir_geo->blksize;
+	*log_dablks = 0;
+	*rmt_blks = 0;
+	*total_dablks = 0;
+
+	/*
+	 * Determine space new attribute will use, and if it would be
+	 * "local" or "remote" (note: local != inline).
+	 */
+	size = xfs_attr_leaf_newentsize(mp, namelen, valuelen, local);
+
+	*total_dablks = XFS_DAENTER_BLOCKS(mp, XFS_ATTR_FORK);
+	*log_dablks = 2 * *total_dablks;
+
+	if (*local) {
+		if (size > (blksize / 2)) {
+			/* Double split possible */
+			*log_dablks += *total_dablks;
+			*total_dablks *= 2;
+		}
+	} else {
+		/*
+		 * Out of line attribute, cannot double split, but
+		 * make room for the attribute value itself.
+		 */
+		*rmt_blks = xfs_attr3_rmt_blocks(mp, valuelen);
+	}
+}
+
 /*
  * Set the attribute specified in @args.
  */
@@ -345,6 +366,9 @@  xfs_attr_set(
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_da_args	args;
 	struct xfs_trans_res	tres;
+	unsigned int		log_dablks;
+	unsigned int		rmt_blks;
+	unsigned int		total_dablks;
 	int			rsvd = (flags & ATTR_ROOT) != 0;
 	int			error, local;
 
@@ -360,7 +384,11 @@  xfs_attr_set(
 	args.value = value;
 	args.valuelen = valuelen;
 	args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
-	args.total = xfs_attr_calc_size(&args, &local);
+
+	xfs_attr_calc_size(mp, args.namelen, args.valuelen, &local,
+			&log_dablks, &rmt_blks, &total_dablks);
+
+	args.total = xfs_calc_attr_blocks(mp, total_dablks, rmt_blks);
 
 	error = xfs_qm_dqattach(dp);
 	if (error)
@@ -379,8 +407,8 @@  xfs_attr_set(
 			return error;
 	}
 
-	tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
-			 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
+	tres.tr_logres = xfs_calc_attr_res(mp, log_dablks, rmt_blks,
+					total_dablks);
 	tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
 	tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
 
diff --git a/libxfs/xfs_attr.h b/libxfs/xfs_attr.h
index 94badfa1..a1c77618 100644
--- a/libxfs/xfs_attr.h
+++ b/libxfs/xfs_attr.h
@@ -154,5 +154,8 @@  int xfs_attr_remove_args(struct xfs_da_args *args);
 int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
 		  int flags, struct attrlist_cursor_kern *cursor);
 bool xfs_attr_namecheck(const void *name, size_t length);
+void xfs_attr_calc_size(struct xfs_mount *mp, int namelen, int valuelen,
+			int *local, unsigned int *log_dablks,
+			unsigned int *rmt_blks, unsigned int *total_dablks);
 
 #endif	/* __XFS_ATTR_H__ */
diff --git a/libxfs/xfs_log_rlimit.c b/libxfs/xfs_log_rlimit.c
index c8398b7d..5e7f7123 100644
--- a/libxfs/xfs_log_rlimit.c
+++ b/libxfs/xfs_log_rlimit.c
@@ -10,6 +10,7 @@ 
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
+#include "xfs_attr.h"
 #include "xfs_da_format.h"
 #include "xfs_trans_space.h"
 #include "xfs_da_btree.h"
@@ -23,17 +24,19 @@  STATIC int
 xfs_log_calc_max_attrsetm_res(
 	struct xfs_mount	*mp)
 {
-	int			size;
-	int			nblks;
+	int		size;
+	int		local;
+	unsigned int	total_dablks;
+	unsigned int	rmt_blks;
+	unsigned int	log_dablks;
 
 	size = xfs_attr_leaf_entsize_local_max(mp->m_attr_geo->blksize) -
 	       MAXNAMELEN - 1;
-	nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
-	nblks += XFS_B_TO_FSB(mp, size);
-	nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK);
+	xfs_attr_calc_size(mp, size, 0, &local, &log_dablks, &rmt_blks,
+			&total_dablks);
+	ASSERT(local == 1);
 
-	return  M_RES(mp)->tr_attrsetm.tr_logres +
-		M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
+	return xfs_calc_attr_res(mp, log_dablks, rmt_blks, total_dablks);
 }
 
 /*
diff --git a/libxfs/xfs_trans_resv.c b/libxfs/xfs_trans_resv.c
index 270e92a3..259a5e83 100644
--- a/libxfs/xfs_trans_resv.c
+++ b/libxfs/xfs_trans_resv.c
@@ -641,12 +641,10 @@  xfs_calc_attrinval_reservation(
  * Setting an attribute at mount time.
  *	the inode getting the attribute
  *	the superblock for allocations
- *	the agfs extents are allocated from
- *	the attribute btree * max depth
- *	the inode allocation btree
+ *	the agf extents are allocated from
  * Since attribute transaction space is dependent on the size of the attribute,
  * the calculation is done partially at mount time and partially at runtime(see
- * below).
+ * xfs_attr_calc_size()).
  */
 STATIC uint
 xfs_calc_attrsetm_reservation(
@@ -654,27 +652,7 @@  xfs_calc_attrsetm_reservation(
 {
 	return XFS_DQUOT_LOGRES(mp) +
 		xfs_calc_inode_res(mp, 1) +
-		xfs_calc_buf_res(1, mp->m_sb.sb_sectsize) +
-		xfs_calc_buf_res(XFS_DA_NODE_MAXDEPTH, XFS_FSB_TO_B(mp, 1));
-}
-
-/*
- * Setting an attribute at runtime, transaction space unit per block.
- * 	the superblock for allocations: sector size
- *	the inode bmap btree could join or split: max depth * block size
- * Since the runtime attribute transaction space is dependent on the total
- * blocks needed for the 1st bmap, here we calculate out the space unit for
- * one block so that the caller could figure out the total space according
- * to the attibute extent length in blocks by:
- *	ext * M_RES(mp)->tr_attrsetrt.tr_logres
- */
-STATIC uint
-xfs_calc_attrsetrt_reservation(
-	struct xfs_mount	*mp)
-{
-	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize) +
-		xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK),
-				 XFS_FSB_TO_B(mp, 1));
+		xfs_calc_buf_res(2, mp->m_sb.sb_sectsize);
 }
 
 /*
@@ -772,6 +750,32 @@  xfs_calc_sb_reservation(
 	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
 }
 
+uint
+xfs_calc_attr_res(
+	struct xfs_mount	*mp,
+	unsigned int		log_dablks,
+	unsigned int		rmt_blks,
+	unsigned int		total_dablks)
+{
+	unsigned int		da_blksize;
+	unsigned int		fs_blksize;
+	unsigned int		bmbt_blks;
+	unsigned int		space_blks;
+
+	bmbt_blks = XFS_NEXTENTADD_SPACE_RES(mp, total_dablks + rmt_blks,
+					XFS_ATTR_FORK);
+	space_blks = xfs_allocfree_log_count(mp,
+					total_dablks + rmt_blks + bmbt_blks);
+
+	da_blksize = mp->m_attr_geo->blksize;
+	fs_blksize = mp->m_sb.sb_blocksize;
+
+	return M_RES(mp)->tr_attrsetm.tr_logres +
+		xfs_calc_buf_res(log_dablks, da_blksize) +
+		xfs_calc_buf_res(bmbt_blks, fs_blksize) +
+		xfs_calc_buf_res(space_blks, fs_blksize);
+}
+
 void
 xfs_trans_resv_calc(
 	struct xfs_mount	*mp,
@@ -882,7 +886,7 @@  xfs_trans_resv_calc(
 	resp->tr_ichange.tr_logres = xfs_calc_ichange_reservation(mp);
 	resp->tr_fsyncts.tr_logres = xfs_calc_swrite_reservation(mp);
 	resp->tr_writeid.tr_logres = xfs_calc_writeid_reservation(mp);
-	resp->tr_attrsetrt.tr_logres = xfs_calc_attrsetrt_reservation(mp);
+	resp->tr_attrsetrt.tr_logres = 0;
 	resp->tr_clearagi.tr_logres = xfs_calc_clear_agi_bucket_reservation(mp);
 	resp->tr_growrtzero.tr_logres = xfs_calc_growrtzero_reservation(mp);
 	resp->tr_growrtfree.tr_logres = xfs_calc_growrtfree_reservation(mp);
diff --git a/libxfs/xfs_trans_resv.h b/libxfs/xfs_trans_resv.h
index 7241ab28..48ceba72 100644
--- a/libxfs/xfs_trans_resv.h
+++ b/libxfs/xfs_trans_resv.h
@@ -91,6 +91,8 @@  struct xfs_trans_resv {
 #define	XFS_ATTRSET_LOG_COUNT		3
 #define	XFS_ATTRRM_LOG_COUNT		3
 
+uint xfs_calc_attr_res(struct xfs_mount *mp, unsigned int log_dablks,
+		unsigned int rmt_blks, unsigned int total_dablks);
 void xfs_trans_resv_calc(struct xfs_mount *mp, struct xfs_trans_resv *resp);
 uint xfs_allocfree_log_count(struct xfs_mount *mp, uint num_ops);