xfs: make is_log_ag() a first class helper

We check if an ag contains the log in many places, so make this
a first class XFS helper by lifting it to fs/xfs/libxfs/xfs_ag.h and
renaming it xfs_ag_contains_log(). The convert all the places that
check if the AG contains the log to use this helper.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_ag.c

@@ -390,12 +390,6 @@ xfs_get_aghdr_buf(
 	return 0;
 }
 
-static inline bool is_log_ag(struct xfs_mount *mp, struct aghdr_init_data *id)
-{
-	return mp->m_sb.sb_logstart > 0 &&
-	       id->agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
-}
-
 /*
  * Generic btree root block init function
  */
@@ -421,7 +415,7 @@ xfs_freesp_init_recs(
 	arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
 	arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
 
-	if (is_log_ag(mp, id)) {
+	if (xfs_ag_contains_log(mp, id->agno)) {
 		struct xfs_alloc_rec	*nrec;
 		xfs_agblock_t		start = XFS_FSB_TO_AGBNO(mp,
 							mp->m_sb.sb_logstart);
@@ -548,7 +542,7 @@ xfs_rmaproot_init(
 	}
 
 	/* account for the log space */
-	if (is_log_ag(mp, id)) {
+	if (xfs_ag_contains_log(mp, id->agno)) {
 		rrec = XFS_RMAP_REC_ADDR(block,
 				be16_to_cpu(block->bb_numrecs) + 1);
 		rrec->rm_startblock = cpu_to_be32(
@@ -619,7 +613,7 @@ xfs_agfblock_init(
 		agf->agf_refcount_blocks = cpu_to_be32(1);
 	}
 
-	if (is_log_ag(mp, id)) {
+	if (xfs_ag_contains_log(mp, id->agno)) {
 		int64_t	logblocks = mp->m_sb.sb_logblocks;
 
 		be32_add_cpu(&agf->agf_freeblks, -logblocks);

fs/xfs/libxfs/xfs_ag.h

@@ -165,6 +165,13 @@ xfs_verify_agino_or_null(struct xfs_perag *pag, xfs_agino_t agino)
 	return xfs_verify_agino(pag, agino);
 }
 
+static inline bool
+xfs_ag_contains_log(struct xfs_mount *mp, xfs_agnumber_t agno)
+{
+	return mp->m_sb.sb_logstart > 0 &&
+	       agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
+}
+
 /*
  * Perag iteration APIs
  */

fs/xfs/libxfs/xfs_ialloc.c

@@ -2897,8 +2897,7 @@ xfs_ialloc_calc_rootino(
 	 * allocation group, or very odd geometries created by old mkfs
 	 * versions on very small filesystems.
 	 */
-	if (mp->m_sb.sb_logstart &&
-	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == 0)
+	if (xfs_ag_contains_log(mp, 0))
 		 first_bno += mp->m_sb.sb_logblocks;
 
 	/*

fs/xfs/libxfs/xfs_ialloc_btree.c

@@ -697,8 +697,7 @@ xfs_inobt_max_size(
 	 * never be available for the kinds of things that would require btree
 	 * expansion.  We therefore can pretend the space isn't there.
 	 */
-	if (mp->m_sb.sb_logstart &&
-	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == pag->pag_agno)
+	if (xfs_ag_contains_log(mp, pag->pag_agno))
 		agblocks -= mp->m_sb.sb_logblocks;
 
 	return xfs_btree_calc_size(M_IGEO(mp)->inobt_mnr,

fs/xfs/libxfs/xfs_refcount_btree.c

@@ -507,8 +507,7 @@ xfs_refcountbt_calc_reserves(
 	 * never be available for the kinds of things that would require btree
 	 * expansion.  We therefore can pretend the space isn't there.
 	 */
-	if (mp->m_sb.sb_logstart &&
-	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == pag->pag_agno)
+	if (xfs_ag_contains_log(mp, pag->pag_agno))
 		agblocks -= mp->m_sb.sb_logblocks;
 
 	*ask += xfs_refcountbt_max_size(mp, agblocks);

fs/xfs/libxfs/xfs_rmap_btree.c

@@ -666,8 +666,7 @@ xfs_rmapbt_calc_reserves(
 	 * never be available for the kinds of things that would require btree
 	 * expansion.  We therefore can pretend the space isn't there.
 	 */
-	if (mp->m_sb.sb_logstart &&
-	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == pag->pag_agno)
+	if (xfs_ag_contains_log(mp, pag->pag_agno))
 		agblocks -= mp->m_sb.sb_logblocks;
 
 	/* Reserve 1% of the AG or enough for 1 block per record. */

fs/xfs/scrub/health.c

@@ -8,6 +8,8 @@
 #include "xfs_shared.h"
 #include "xfs_format.h"
 #include "xfs_btree.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
 #include "xfs_ag.h"
 #include "xfs_health.h"
 #include "scrub/scrub.h"

fs/xfs/scrub/refcount.c

@@ -13,6 +13,8 @@
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/btree.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
 #include "xfs_ag.h"
 
 /*