On Tue, Jul 27, 2021 at 02:56:11PM -0700, Darrick J. Wong wrote:

On Mon, Jul 26, 2021 at 05:15:31PM +0530, Chandan Babu R wrote:

quoted

In preparation for introducing larger extent count limits, this commit renames
existing extent count limits based on their signedness and width.

Signed-off-by: Chandan Babu R <redacted>
---
 fs/xfs/libxfs/xfs_bmap.c       | 4 ++--
 fs/xfs/libxfs/xfs_format.h     | 8 ++++----
 fs/xfs/libxfs/xfs_inode_buf.c  | 4 ++--
 fs/xfs/libxfs/xfs_inode_fork.c | 3 ++-
 fs/xfs/scrub/inode_repair.c    | 2 +-
 5 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index f3c9a0ebb0a5..8f262405a5b5 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c

@@ -76,10 +76,10 @@ xfs_bmap_compute_maxlevels(
 	 * available.
 	 */
 	if (whichfork == XFS_DATA_FORK) {
-		maxleafents = MAXEXTNUM;
+		maxleafents = XFS_IFORK_EXTCNT_MAXS32;

I'm not in love with these names, since they tell me roughly about the
size of the constant (which I could glean from the definition) but less
about when I would expect to find them.  How about:

#define XFS_MAX_DFORK_NEXTENTS    ((xfs_extnum_t) 0x7FFFFFFF)
#define XFS_MAX_AFORK_NEXTENTS    ((xfs_aextnum_t)0x00007FFF)

Or, given that 'DFORK' already means 'ondisk fork', how about:

XFS_MAX_DATA_NEXTENTS
XFS_MAX_ATTR_NEXTENTS

?

--D

and when we get to the iext64 feature (or whatever we end up calling it)
then we can define new ones:

#define XFS_MAX_DFORK_NEXTENTS64  ((xfs_extnum_t) 0xFFFFFFFFFFFF)
#define XFS_MAX_AFORK_NEXTENTS64  ((xfs_aextnum_t)0x0000FFFFFFFF)

or something like that.

quoted

 		sz = xfs_bmdr_space_calc(MINDBTPTRS);
 	} else {
-		maxleafents = MAXAEXTNUM;
+		maxleafents = XFS_IFORK_EXTCNT_MAXS16;
 		sz = xfs_bmdr_space_calc(MINABTPTRS);
 	}
 	maxrootrecs = xfs_bmdr_maxrecs(sz, 0);

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 37cca918d2ba..920e3f9c418f 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h

@@ -1110,11 +1110,11 @@ enum xfs_dinode_fmt {
 	{ XFS_DINODE_FMT_UUID,		"uuid" }
 
 /*
- * Max values for extlen, extnum, aextnum.
+ * Max values for extlen and disk inode's extent counters.
  */
-#define	MAXEXTLEN	((uint32_t)0x001fffff)	/* 21 bits */

As for MAXEXTLEN... would you mind tacking a new patch on the end to fix
its definition as well?  It /really/ ought to be based on the disk
format definitions and not open-coded.

#define XFS_MAX_EXTLEN		((xfs_extlen_t)(1 << BMBT_BLOCKCOUNT_BITLEN) - 1)

--D

quoted

-#define	MAXEXTNUM	((int32_t)0x7fffffff)	/* signed int */
-#define	MAXAEXTNUM	((int16_t)0x7fff)	/* signed short */
+#define	MAXEXTLEN		((uint32_t)0x1fffff) /* 21 bits */
+#define XFS_IFORK_EXTCNT_MAXS32 ((int32_t)0x7fffffff)  /* Signed 32-bits */
+#define XFS_IFORK_EXTCNT_MAXS16 ((int16_t)0x7fff)      /* Signed 16-bits */
 
 /*
  * Inode minimum and maximum sizes.

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index 5625df1ddd95..66d13e8fa420 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c

@@ -365,9 +365,9 @@ xfs_dinode_verify_fork(
 		break;
 	case XFS_DINODE_FMT_BTREE:
 		if (whichfork == XFS_ATTR_FORK) {
-			if (di_nextents > MAXAEXTNUM)
+			if (di_nextents > XFS_IFORK_EXTCNT_MAXS16)
 				return __this_address;
-		} else if (di_nextents > MAXEXTNUM) {
+		} else if (di_nextents > XFS_IFORK_EXTCNT_MAXS32) {
 			return __this_address;
 		}
 		break;

diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 801a6f7dbd0c..6f4b14d3d381 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c

@@ -736,7 +736,8 @@ xfs_iext_count_may_overflow(
 	if (whichfork == XFS_COW_FORK)
 		return 0;
 
-	max_exts = (whichfork == XFS_ATTR_FORK) ? MAXAEXTNUM : MAXEXTNUM;
+	max_exts = (whichfork == XFS_ATTR_FORK) ?
+		XFS_IFORK_EXTCNT_MAXS16 : XFS_IFORK_EXTCNT_MAXS32;
 
 	if (XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
 		max_exts = 10;

diff --git a/fs/xfs/scrub/inode_repair.c b/fs/xfs/scrub/inode_repair.c
index a80cd633fe59..c44f8d06939b 100644
--- a/fs/xfs/scrub/inode_repair.c
+++ b/fs/xfs/scrub/inode_repair.c

@@ -1198,7 +1198,7 @@ xrep_inode_blockcounts(
 			return error;
 		if (count >= sc->mp->m_sb.sb_dblocks)
 			return -EFSCORRUPTED;
-		if (nextents >= MAXAEXTNUM)
+		if (nextents >= XFS_IFORK_EXTCNT_MAXS16)
 			return -EFSCORRUPTED;
 		ifp->if_nextents = nextents;
 	} else {

-- 
2.30.2