xfs: introduce xfs_bulkstat_grab_ichunk

From: Jie Liu <jeff.liu@oracle.com>

Introduce xfs_bulkstat_grab_ichunk() to look up an inode chunk in where
the given inode resides, then grab the record.  Update the data for the
pointed-to record if the inode was not the last in the chunk and there
are some left allocated, return the grabbed inode count on success.

Refactor xfs_bulkstat() with it.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 69 insertions, 50 deletions

diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index b50816789f2b..32cf52ee33bc 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -203,6 +203,63 @@ xfs_bulkstat_ichunk_ra(
         blk_finish_plug(&plug);
 }
 
+/*
+ * Lookup the inode chunk that the given inode lives in and then get the record
+ * if we found the chunk.  If the inode was not the last in the chunk and there
+ * are some left allocated, update the data for the pointed-to record as well as
+ * return the count of grabbed inodes.
+ */
+STATIC int
+xfs_bulkstat_grab_ichunk(
+        struct xfs_btree_cur            *cur,   /* btree cursor */
+        xfs_agino_t                     agino,  /* starting inode of chunk */
+        int                             *icount,/* return # of inodes grabbed */
+        struct xfs_inobt_rec_incore     *irec)  /* btree record */
+{
+        int                             idx;    /* index into inode chunk */
+        int                             stat;
+        int                             error = 0;
+
+        /* Lookup the inode chunk that this inode lives in */
+        error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &stat);
+        if (error)
+                return error;
+        if (!stat) {
+                *icount = 0;
+                return error;
+        }
+
+        /* Get the record, should always work */
+        error = xfs_inobt_get_rec(cur, irec, &stat);
+        if (error)
+                return error;
+        XFS_WANT_CORRUPTED_RETURN(stat == 1);
+
+        /* Check if the record contains the inode in request */
+        if (irec->ir_startino + XFS_INODES_PER_CHUNK <= agino)
+                return -EINVAL;
+
+        idx = agino - irec->ir_startino + 1;
+        if (idx < XFS_INODES_PER_CHUNK &&
+            (xfs_inobt_maskn(idx, XFS_INODES_PER_CHUNK - idx) & ~irec->ir_free)) {
+                int     i;
+
+                /* We got a right chunk with some left inodes allocated at it.
+                 * Grab the chunk record.  Mark all the uninteresting inodes
+                 * free -- because they're before our start point.
+                 */
+                for (i = 0; i < idx; i++) {
+                        if (XFS_INOBT_MASK(i) & ~irec->ir_free)
+                                irec->ir_freecount++;
+                }
+
+                irec->ir_free |= xfs_inobt_maskn(0, idx);
+                *icount = XFS_INODES_PER_CHUNK - irec->ir_freecount;
+        }
+
+        return 0;
+}
+
 #define XFS_BULKSTAT_UBLEFT(ubleft)     ((ubleft) >= statstruct_size)
 
 /*
@@ -290,67 +347,29 @@ xfs_bulkstat(
                 irbp = irbuf;
                 irbufend = irbuf + nirbuf;
                 end_of_ag = 0;
-                /*
-                 * If we're returning in the middle of an allocation group,
-                 * we need to get the remainder of the chunk we're in.
-                 */
+                icount = 0;
                 if (agino > 0) {
-                        xfs_inobt_rec_incore_t r;
-
                         /*
-                         * Lookup the inode chunk that this inode lives in.
+                         * In the middle of an allocation group, we need to get
+                         * the remainder of the chunk we're in.
                          */
-                        error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE,
-                                                 &tmp);
-                        if (!error &&   /* no I/O error */
-                            tmp &&      /* lookup succeeded */
-                                        /* got the record, should always work */
-                            !(error = xfs_inobt_get_rec(cur, &r, &i)) &&
-                            i == 1 &&
-                                        /* this is the right chunk */
-                            agino < r.ir_startino + XFS_INODES_PER_CHUNK &&
-                                        /* lastino was not last in chunk */
-                            (chunkidx = agino - r.ir_startino + 1) <
-                                    XFS_INODES_PER_CHUNK &&
-                                        /* there are some left allocated */
-                            xfs_inobt_maskn(chunkidx,
-                                    XFS_INODES_PER_CHUNK - chunkidx) &
-                                    ~r.ir_free) {
-                                /*
-                                 * Grab the chunk record.  Mark all the
-                                 * uninteresting inodes (because they're
-                                 * before our start point) free.
-                                 */
-                                for (i = 0; i < chunkidx; i++) {
-                                        if (XFS_INOBT_MASK(i) & ~r.ir_free)
-                                                r.ir_freecount++;
-                                }
-                                r.ir_free |= xfs_inobt_maskn(0, chunkidx);
+                        struct xfs_inobt_rec_incore     r;
+
+                        error = xfs_bulkstat_grab_ichunk(cur, agino, &icount, &r);
+                        if (error)
+                                break;
+                        if (icount) {
                                 irbp->ir_startino = r.ir_startino;
                                 irbp->ir_freecount = r.ir_freecount;
                                 irbp->ir_free = r.ir_free;
                                 irbp++;
                                 agino = r.ir_startino + XFS_INODES_PER_CHUNK;
-                                icount = XFS_INODES_PER_CHUNK - r.ir_freecount;
-                        } else {
-                                /*
-                                 * If any of those tests failed, bump the
-                                 * inode number (just in case).
-                                 */
-                                agino++;
-                                icount = 0;
                         }
-                        /*
-                         * In any case, increment to the next record.
-                         */
-                        if (!error)
-                                error = xfs_btree_increment(cur, 0, &tmp);
+                        /* Increment to the next record */
+                        error = xfs_btree_increment(cur, 0, &tmp);
                 } else {
-                        /*
-                         * Start of ag.  Lookup the first inode chunk.
-                         */
+                        /* Start of ag.  Lookup the first inode chunk */
                         error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &tmp);
-                        icount = 0;
                 }
                 if (error)
                         break;