xfs: factor dir2 free block reading

Also factor out the updating of the free block when removing entries
from leaf blocks, and add a verifier callback for reads.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

3 files changed, 143 insertions, 80 deletions

diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c
index 86e3dc1de0e7..6c1359dc9898 100644
--- a/fs/xfs/xfs_dir2_leaf.c
+++ b/fs/xfs/xfs_dir2_leaf.c
@@ -1863,8 +1863,7 @@ xfs_dir2_node_to_leaf(
         /*
          * Read the freespace block.
          */
-        error = xfs_da_read_buf(tp, dp,  mp->m_dirfreeblk, -1, &fbp,
-                                XFS_DATA_FORK, NULL);
+        error = xfs_dir2_free_read(tp, dp,  mp->m_dirfreeblk, &fbp);
         if (error)
                 return error;
         free = fbp->b_addr;
diff --git a/fs/xfs/xfs_dir2_node.c b/fs/xfs/xfs_dir2_node.c
index 290c2b1016ab..d7f899dfbff5 100644
--- a/fs/xfs/xfs_dir2_node.c
+++ b/fs/xfs/xfs_dir2_node.c
@@ -55,6 +55,57 @@ static int xfs_dir2_leafn_remove(xfs_da_args_t *args, struct xfs_buf *bp,
 static int xfs_dir2_node_addname_int(xfs_da_args_t *args,
                                      xfs_da_state_blk_t *fblk);
 
+static void
+xfs_dir2_free_verify(
+        struct xfs_buf          *bp)
+{
+        struct xfs_mount        *mp = bp->b_target->bt_mount;
+        struct xfs_dir2_free_hdr *hdr = bp->b_addr;
+        int                     block_ok = 0;
+
+        block_ok = hdr->magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC);
+        if (!block_ok) {
+                XFS_CORRUPTION_ERROR("xfs_dir2_free_verify magic",
+                                     XFS_ERRLEVEL_LOW, mp, hdr);
+                xfs_buf_ioerror(bp, EFSCORRUPTED);
+        }
+
+        bp->b_iodone = NULL;
+        xfs_buf_ioend(bp, 0);
+}
+
+static int
+__xfs_dir2_free_read(
+        struct xfs_trans        *tp,
+        struct xfs_inode        *dp,
+        xfs_dablk_t             fbno,
+        xfs_daddr_t             mappedbno,
+        struct xfs_buf          **bpp)
+{
+        return xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
+                                        XFS_DATA_FORK, xfs_dir2_free_verify);
+}
+
+int
+xfs_dir2_free_read(
+        struct xfs_trans        *tp,
+        struct xfs_inode        *dp,
+        xfs_dablk_t             fbno,
+        struct xfs_buf          **bpp)
+{
+        return __xfs_dir2_free_read(tp, dp, fbno, -1, bpp);
+}
+
+static int
+xfs_dir2_free_try_read(
+        struct xfs_trans        *tp,
+        struct xfs_inode        *dp,
+        xfs_dablk_t             fbno,
+        struct xfs_buf          **bpp)
+{
+        return __xfs_dir2_free_read(tp, dp, fbno, -2, bpp);
+}
+
 /*
  * Log entries from a freespace block.
  */
@@ -394,12 +445,10 @@ xfs_dir2_leafn_lookup_for_addname(
                                  */
                                 if (curbp)
                                         xfs_trans_brelse(tp, curbp);
-                                /*
-                                 * Read the free block.
-                                 */
-                                error = xfs_da_read_buf(tp, dp,
+
+                                error = xfs_dir2_free_read(tp, dp,
                                                 xfs_dir2_db_to_da(mp, newfdb),
-                                                -1, &curbp, XFS_DATA_FORK, NULL);
+                                                &curbp);
                                 if (error)
                                         return error;
                                 free = curbp->b_addr;
@@ -825,6 +874,77 @@ xfs_dir2_leafn_rebalance(
         }
 }
 
+static int
+xfs_dir2_data_block_free(
+        xfs_da_args_t           *args,
+        struct xfs_dir2_data_hdr *hdr,
+        struct xfs_dir2_free    *free,
+        xfs_dir2_db_t           fdb,
+        int                     findex,
+        struct xfs_buf          *fbp,
+        int                     longest)
+{
+        struct xfs_trans        *tp = args->trans;
+        int                     logfree = 0;
+
+        if (!hdr) {
+                /* One less used entry in the free table.  */
+                be32_add_cpu(&free->hdr.nused, -1);
+                xfs_dir2_free_log_header(tp, fbp);
+
+                /*
+                 * If this was the last entry in the table, we can trim the
+                 * table size back.  There might be other entries at the end
+                 * referring to non-existent data blocks, get those too.
+                 */
+                if (findex == be32_to_cpu(free->hdr.nvalid) - 1) {
+                        int     i;              /* free entry index */
+
+                        for (i = findex - 1; i >= 0; i--) {
+                                if (free->bests[i] != cpu_to_be16(NULLDATAOFF))
+                                        break;
+                        }
+                        free->hdr.nvalid = cpu_to_be32(i + 1);
+                        logfree = 0;
+                } else {
+                        /* Not the last entry, just punch it out.  */
+                        free->bests[findex] = cpu_to_be16(NULLDATAOFF);
+                        logfree = 1;
+                }
+                /*
+                 * If there are no useful entries left in the block,
+                 * get rid of the block if we can.
+                 */
+                if (!free->hdr.nused) {
+                        int error;
+
+                        error = xfs_dir2_shrink_inode(args, fdb, fbp);
+                        if (error == 0) {
+                                fbp = NULL;
+                                logfree = 0;
+                        } else if (error != ENOSPC || args->total != 0)
+                                return error;
+                        /*
+                         * It's possible to get ENOSPC if there is no
+                         * space reservation.  In this case some one
+                         * else will eventually get rid of this block.
+                         */
+                }
+        } else {
+                /*
+                 * Data block is not empty, just set the free entry to the new
+                 * value.
+                 */
+                free->bests[findex] = cpu_to_be16(longest);
+                logfree = 1;
+        }
+
+        /* Log the free entry that changed, unless we got rid of it.  */
+        if (logfree)
+                xfs_dir2_free_log_bests(tp, fbp, findex, findex);
+        return 0;
+}
+
 /*
  * Remove an entry from a node directory.
  * This removes the leaf entry and the data entry,
@@ -908,15 +1028,14 @@ xfs_dir2_leafn_remove(
                 xfs_dir2_db_t   fdb;            /* freeblock block number */
                 int             findex;         /* index in freeblock entries */
                 xfs_dir2_free_t *free;          /* freeblock structure */
-                int             logfree;        /* need to log free entry */
 
                 /*
                  * Convert the data block number to a free block,
                  * read in the free block.
                  */
                 fdb = xfs_dir2_db_to_fdb(mp, db);
-                error = xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, fdb),
-                                        -1, &fbp, XFS_DATA_FORK, NULL);
+                error = xfs_dir2_free_read(tp, dp, xfs_dir2_db_to_da(mp, fdb),
+                                           &fbp);
                 if (error)
                         return error;
                 free = fbp->b_addr;
@@ -954,68 +1073,12 @@ xfs_dir2_leafn_remove(
                  * If we got rid of the data block, we can eliminate that entry
                  * in the free block.
                  */
-                if (hdr == NULL) {
-                        /*
-                         * One less used entry in the free table.
-                         */
-                        be32_add_cpu(&free->hdr.nused, -1);
-                        xfs_dir2_free_log_header(tp, fbp);
-                        /*
-                         * If this was the last entry in the table, we can
-                         * trim the table size back.  There might be other
-                         * entries at the end referring to non-existent
-                         * data blocks, get those too.
-                         */
-                        if (findex == be32_to_cpu(free->hdr.nvalid) - 1) {
-                                int     i;              /* free entry index */
-
-                                for (i = findex - 1;
-                                     i >= 0 &&
-                                     free->bests[i] == cpu_to_be16(NULLDATAOFF);
-                                     i--)
-                                        continue;
-                                free->hdr.nvalid = cpu_to_be32(i + 1);
-                                logfree = 0;
-                        }
-                        /*
-                         * Not the last entry, just punch it out.
-                         */
-                        else {
-                                free->bests[findex] = cpu_to_be16(NULLDATAOFF);
-                                logfree = 1;
-                        }
-                        /*
-                         * If there are no useful entries left in the block,
-                         * get rid of the block if we can.
-                         */
-                        if (!free->hdr.nused) {
-                                error = xfs_dir2_shrink_inode(args, fdb, fbp);
-                                if (error == 0) {
-                                        fbp = NULL;
-                                        logfree = 0;
-                                } else if (error != ENOSPC || args->total != 0)
-                                        return error;
-                                /*
-                                 * It's possible to get ENOSPC if there is no
-                                 * space reservation.  In this case some one
-                                 * else will eventually get rid of this block.
-                                 */
-                        }
-                }
-                /*
-                 * Data block is not empty, just set the free entry to
-                 * the new value.
-                 */
-                else {
-                        free->bests[findex] = cpu_to_be16(longest);
-                        logfree = 1;
-                }
-                /*
-                 * Log the free entry that changed, unless we got rid of it.
-                 */
-                if (logfree)
-                        xfs_dir2_free_log_bests(tp, fbp, findex, findex);
+                error = xfs_dir2_data_block_free(args, hdr, free,
+                                                 fdb, findex, fbp, longest);
+                if (error)
+                        return error;
         }
+
         xfs_dir2_leafn_check(dp, bp);
         /*
          * Return indication of whether this leaf block is empty enough
@@ -1453,9 +1516,9 @@ xfs_dir2_node_addname_int(
                          * This should be really rare, so there's no reason
                          * to avoid it.
                          */
-                        error = xfs_da_read_buf(tp, dp,
-                                                xfs_dir2_db_to_da(mp, fbno), -2,
-                                                &fbp, XFS_DATA_FORK, NULL);
+                        error = xfs_dir2_free_try_read(tp, dp,
+                                                xfs_dir2_db_to_da(mp, fbno),
+                                                &fbp);
                         if (error)
                                 return error;
                         if (!fbp)
@@ -1518,8 +1581,9 @@ xfs_dir2_node_addname_int(
                  * that was just allocated.
                  */
                 fbno = xfs_dir2_db_to_fdb(mp, dbno);
-                error = xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, fbno), -2,
-                                        &fbp, XFS_DATA_FORK, NULL);
+                error = xfs_dir2_free_try_read(tp, dp,
+                                               xfs_dir2_db_to_da(mp, fbno),
+                                               &fbp);
                 if (error)
                         return error;
 
@@ -1915,17 +1979,15 @@ xfs_dir2_node_trim_free(
         /*
          * Read the freespace block.
          */
-        error = xfs_da_read_buf(tp, dp, (xfs_dablk_t)fo, -2, &bp,
-                                XFS_DATA_FORK, NULL);
+        error = xfs_dir2_free_try_read(tp, dp, fo, &bp);
         if (error)
                 return error;
         /*
          * There can be holes in freespace.  If fo is a hole, there's
          * nothing to do.
          */
-        if (bp == NULL) {
+        if (!bp)
                 return 0;
-        }
         free = bp->b_addr;
         ASSERT(free->hdr.magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC));
         /*
diff --git a/fs/xfs/xfs_dir2_priv.h b/fs/xfs/xfs_dir2_priv.h
index 93b8f66ae788..263a63287910 100644
--- a/fs/xfs/xfs_dir2_priv.h
+++ b/fs/xfs/xfs_dir2_priv.h
@@ -117,6 +117,8 @@ extern int xfs_dir2_node_removename(struct xfs_da_args *args);
 extern int xfs_dir2_node_replace(struct xfs_da_args *args);
 extern int xfs_dir2_node_trim_free(struct xfs_da_args *args, xfs_fileoff_t fo,
                 int *rvalp);
+extern int xfs_dir2_free_read(struct xfs_trans *tp, struct xfs_inode *dp,
+                xfs_dablk_t fbno, struct xfs_buf **bpp);
 
 /* xfs_dir2_sf.c */
 extern xfs_ino_t xfs_dir2_sf_get_parent_ino(struct xfs_dir2_sf_hdr *sfp);