xfs: devirtualize ->m_dirnameops

Instead of causing a relatively expensive indirect call for each
hashing and comparism of a file name in a directory just use an
inline function and a simple branch on the ASCII CI bit.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>
[darrick: fix unused variable warning]
Signed-off-by: Darrick J. Wong <[e-mail]>

fs/xfs/libxfs/xfs_da_btree.c

···
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_mount.h"
+#include "xfs_inode.h"
 #include "xfs_dir2.h"
 #include "xfs_dir2_priv.h"
-#include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_bmap.h"
 #include "xfs_attr_leaf.h"
···
 	return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
 					XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
 }
-
-static xfs_dahash_t
-xfs_default_hashname(
-	struct xfs_name	*name)
-{
-	return xfs_da_hashname(name->name, name->len);
-}
-
-const struct xfs_nameops xfs_default_nameops = {
-	.hashname	= xfs_default_hashname,
-	.compname	= xfs_da_compname
-};
 
 int
 xfs_da_grow_inode_int(

fs/xfs/libxfs/xfs_da_btree.h

···
 		(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 		(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
 
-/*
- * Name ops for directory and/or attr name operations
- */
-struct xfs_nameops {
-	xfs_dahash_t	(*hashname)(struct xfs_name *);
-	enum xfs_dacmp	(*compname)(struct xfs_da_args *,
-					const unsigned char *, int);
-};
-
-
 /*========================================================================
  * Function prototypes.
  *========================================================================*/
···
 		struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from);
 
 extern struct kmem_zone *xfs_da_state_zone;
-extern const struct xfs_nameops xfs_default_nameops;
 
 #endif	/* __XFS_DA_BTREE_H__ */

fs/xfs/libxfs/xfs_dir2.c

···
  * ASCII case-insensitive (ie. A-Z) support for directories that was
  * used in IRIX.
  */
-STATIC xfs_dahash_t
+xfs_dahash_t
 xfs_ascii_ci_hashname(
 	struct xfs_name	*name)
 {
···
 	return hash;
 }
 
-STATIC enum xfs_dacmp
+enum xfs_dacmp
 xfs_ascii_ci_compname(
-	struct xfs_da_args *args,
-	const unsigned char *name,
-	int		len)
+	struct xfs_da_args	*args,
+	const unsigned char	*name,
+	int			len)
 {
-	enum xfs_dacmp	result;
-	int		i;
+	enum xfs_dacmp		result;
+	int			i;
 
 	if (args->namelen != len)
 		return XFS_CMP_DIFFERENT;
···
 
 	return result;
 }
-
-static const struct xfs_nameops xfs_ascii_ci_nameops = {
-	.hashname	= xfs_ascii_ci_hashname,
-	.compname	= xfs_ascii_ci_compname,
-};
 
 int
 xfs_da_mount(
···
 	dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
 				(uint)sizeof(xfs_da_node_entry_t);
 	dageo->magicpct = (dageo->blksize * 37) / 100;
-
-	if (xfs_sb_version_hasasciici(&mp->m_sb))
-		mp->m_dirnameops = &xfs_ascii_ci_nameops;
-	else
-		mp->m_dirnameops = &xfs_default_nameops;
-
 	return 0;
 }
 
···
 	args->name = name->name;
 	args->namelen = name->len;
 	args->filetype = name->type;
-	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
 	args->inumber = inum;
 	args->dp = dp;
 	args->total = total;
···
 	args->name = name->name;
 	args->namelen = name->len;
 	args->filetype = name->type;
-	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
 	args->dp = dp;
 	args->whichfork = XFS_DATA_FORK;
 	args->trans = tp;
···
 	args->name = name->name;
 	args->namelen = name->len;
 	args->filetype = name->type;
-	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
 	args->inumber = ino;
 	args->dp = dp;
 	args->total = total;
···
 	args->name = name->name;
 	args->namelen = name->len;
 	args->filetype = name->type;
-	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
 	args->inumber = inum;
 	args->dp = dp;
 	args->total = total;

fs/xfs/libxfs/xfs_dir2_block.c

···
 	int			high;		/* binary search high index */
 	int			low;		/* binary search low index */
 	int			mid;		/* binary search current idx */
-	xfs_mount_t		*mp;		/* filesystem mount point */
 	xfs_trans_t		*tp;		/* transaction pointer */
 	enum xfs_dacmp		cmp;		/* comparison result */
 
 	dp = args->dp;
 	tp = args->trans;
-	mp = dp->i_mount;
 
 	error = xfs_dir3_block_read(tp, dp, &bp);
 	if (error)
···
 		 * and buffer. If it's the first case-insensitive match, store
 		 * the index and buffer and continue looking for an exact match.
 		 */
-		cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
+		cmp = xfs_dir2_compname(args, dep->name, dep->namelen);
 		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
 			args->cmpresult = cmp;
 			*bpp = bp;
···
 		xfs_dir2_data_log_entry(args, bp, dep);
 		name.name = sfep->name;
 		name.len = sfep->namelen;
-		blp[2 + i].hashval =
-			cpu_to_be32(mp->m_dirnameops->hashname(&name));
+		blp[2 + i].hashval = cpu_to_be32(xfs_dir2_hashname(mp, &name));
 		blp[2 + i].address =
 			cpu_to_be32(xfs_dir2_byte_to_dataptr(newoffset));
 		offset = (int)((char *)(tagp + 1) - (char *)hdr);

fs/xfs/libxfs/xfs_dir2_data.c

···
 						((char *)dep - (char *)hdr));
 			name.name = dep->name;
 			name.len = dep->namelen;
-			hash = mp->m_dirnameops->hashname(&name);
+			hash = xfs_dir2_hashname(mp, &name);
 			for (i = 0; i < be32_to_cpu(btp->count); i++) {
 				if (be32_to_cpu(lep[i].address) == addr &&
 				    be32_to_cpu(lep[i].hashval) == hash)

fs/xfs/libxfs/xfs_dir2_leaf.c

···
 		 * and buffer. If it's the first case-insensitive match, store
 		 * the index and buffer and continue looking for an exact match.
 		 */
-		cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
+		cmp = xfs_dir2_compname(args, dep->name, dep->namelen);
 		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
 			args->cmpresult = cmp;
 			*indexp = index;

fs/xfs/libxfs/xfs_dir2_node.c

···
 		 * EEXIST immediately. If it's the first case-insensitive
 		 * match, store the block & inode number and continue looking.
 		 */
-		cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
+		cmp = xfs_dir2_compname(args, dep->name, dep->namelen);
 		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
 			/* If there is a CI match block, drop it */
 			if (args->cmpresult != XFS_CMP_DIFFERENT &&

fs/xfs/libxfs/xfs_dir2_priv.h

···
 };
 
 /* xfs_dir2.c */
+xfs_dahash_t xfs_ascii_ci_hashname(struct xfs_name *name);
+enum xfs_dacmp xfs_ascii_ci_compname(struct xfs_da_args *args,
+		const unsigned char *name, int len);
 extern int xfs_dir2_grow_inode(struct xfs_da_args *args, int space,
 				xfs_dir2_db_t *dbp);
 extern int xfs_dir_cilookup_result(struct xfs_da_args *args,
···
 	if (xfs_sb_version_hasftype(&mp->m_sb))
 		len += sizeof(uint8_t);
 	return round_up(len, XFS_DIR2_DATA_ALIGN);
+}
+
+static inline xfs_dahash_t
+xfs_dir2_hashname(
+	struct xfs_mount	*mp,
+	struct xfs_name		*name)
+{
+	if (unlikely(xfs_sb_version_hasasciici(&mp->m_sb)))
+		return xfs_ascii_ci_hashname(name);
+	return xfs_da_hashname(name->name, name->len);
+}
+
+static inline enum xfs_dacmp
+xfs_dir2_compname(
+	struct xfs_da_args	*args,
+	const unsigned char	*name,
+	int			len)
+{
+	if (unlikely(xfs_sb_version_hasasciici(&args->dp->i_mount->m_sb)))
+		return xfs_ascii_ci_compname(args, name, len);
+	return xfs_da_compname(args, name, len);
 }
 
 #endif /* __XFS_DIR2_PRIV_H__ */

fs/xfs/libxfs/xfs_dir2_sf.c

···
 		 * number. If it's the first case-insensitive match, store the
 		 * inode number and continue looking for an exact match.
 		 */
-		cmp = dp->i_mount->m_dirnameops->compname(args, sfep->name,
-								sfep->namelen);
+		cmp = xfs_dir2_compname(args, sfep->name, sfep->namelen);
 		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
 			args->cmpresult = cmp;
 			args->inumber = xfs_dir2_sf_get_ino(mp, sfp, sfep);

fs/xfs/xfs_mount.h

···
 struct xlog;
 struct xfs_inode;
 struct xfs_mru_cache;
-struct xfs_nameops;
 struct xfs_ail;
 struct xfs_quotainfo;
 struct xfs_da_geometry;
···
 	int			m_dalign;	/* stripe unit */
 	int			m_swidth;	/* stripe width */
 	uint8_t			m_sectbb_log;	/* sectlog - BBSHIFT */
-	const struct xfs_nameops *m_dirnameops;	/* vector of dir name ops */
 	atomic_t		m_active_trans;	/* number trans frozen */
 	struct xfs_mru_cache	*m_filestream;  /* per-mount filestream data */
 	struct delayed_work	m_reclaim_work;	/* background inode reclaim */