xfs: fix up inode32/64 (re)mount handling

inode32/inode64 allocator behavior with respect to mount, remount
and growfs is a little tricky.

The inode32 mount option should only enable the inode32 allocator
heuristics if the filesystem is large enough for 64-bit inodes to
exist.  Today, it has this behavior on the initial mount, but a
remount with inode32 unconditionally changes the allocation
heuristics, even for a small fs.

Also, an inode32 mounted small filesystem should transition to the
inode32 allocator if the filesystem is subsequently grown to a
sufficient size.  Today that does not happen.

This patch consolidates xfs_set_inode32 and xfs_set_inode64 into a
single new function, and moves the "is the maximum inode number big
enough to matter" test into that function, so it doesn't rely on the
caller to get it right - which remount did not do, previously.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index bb753b3..a773ef3 100644 (file)
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -185,9 +185,6 @@ xfs_initialize_perag(
        xfs_agnumber_t  index;
        xfs_agnumber_t  first_initialised = 0;
        xfs_perag_t     *pag;
-       xfs_agino_t     agino;
-       xfs_ino_t       ino;
-       xfs_sb_t        *sbp = &mp->m_sb;
        int             error = -ENOMEM;
 
        /*
@@ -230,22 +227,7 @@ xfs_initialize_perag(
                radix_tree_preload_end();
        }
 
-       /*
-        * If we mount with the inode64 option, or no inode overflows
-        * the legacy 32-bit address space clear the inode32 option.
-        */
-       agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
-       ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
-
-       if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
-               mp->m_flags |= XFS_MOUNT_32BITINODES;
-       else
-               mp->m_flags &= ~XFS_MOUNT_32BITINODES;
-
-       if (mp->m_flags & XFS_MOUNT_32BITINODES)
-               index = xfs_set_inode32(mp, agcount);
-       else
-               index = xfs_set_inode64(mp, agcount);
+       index = xfs_set_inode_alloc(mp, agcount);
 
        if (maxagi)
                *maxagi = index;

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index b570984..af01458 100644 (file)
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -166,9 +166,8 @@ typedef struct xfs_mount {
 #define XFS_MOUNT_GRPID                (1ULL << 9)     /* group-ID assigned from directory */
 #define XFS_MOUNT_NORECOVERY   (1ULL << 10)    /* no recovery - dirty fs */
 #define XFS_MOUNT_DFLT_IOSIZE  (1ULL << 12)    /* set default i/o size */
-#define XFS_MOUNT_32BITINODES  (1ULL << 14)    /* do not create inodes above
-                                                * 32 bits in size */
-#define XFS_MOUNT_SMALL_INUMS  (1ULL << 15)    /* users wants 32bit inodes */
+#define XFS_MOUNT_SMALL_INUMS  (1ULL << 14)    /* user wants 32bit inodes */
+#define XFS_MOUNT_32BITINODES  (1ULL << 15)    /* inode32 allocator active */
 #define XFS_MOUNT_NOUUID       (1ULL << 16)    /* ignore uuid during mount */
 #define XFS_MOUNT_BARRIER      (1ULL << 17)
 #define XFS_MOUNT_IKEEP                (1ULL << 18)    /* keep empty inode clusters*/

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 8dd7d16..d85087b 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -580,23 +580,35 @@ xfs_max_file_offset(
 }
 
 /*
- * xfs_set_inode32() and xfs_set_inode64() are passed an agcount
- * because in the growfs case, mp->m_sb.sb_agcount is not updated
- * yet to the potentially higher ag count.
+ * Set parameters for inode allocation heuristics, taking into account
+ * filesystem size and inode32/inode64 mount options; i.e. specifically
+ * whether or not XFS_MOUNT_SMALL_INUMS is set.
+ *
+ * Inode allocation patterns are altered only if inode32 is requested
+ * (XFS_MOUNT_SMALL_INUMS), and the filesystem is sufficiently large.
+ * If altered, XFS_MOUNT_32BITINODES is set as well.
+ *
+ * An agcount independent of that in the mount structure is provided
+ * because in the growfs case, mp->m_sb.sb_agcount is not yet updated
+ * to the potentially higher ag count.
+ *
+ * Returns the maximum AG index which may contain inodes.
  */
 xfs_agnumber_t
-xfs_set_inode32(struct xfs_mount *mp, xfs_agnumber_t agcount)
+xfs_set_inode_alloc(
+       struct xfs_mount *mp,
+       xfs_agnumber_t  agcount)
 {
-       xfs_agnumber_t  index = 0;
+       xfs_agnumber_t  index;
        xfs_agnumber_t  maxagi = 0;
        xfs_sb_t        *sbp = &mp->m_sb;
        xfs_agnumber_t  max_metadata;
        xfs_agino_t     agino;
        xfs_ino_t       ino;
-       xfs_perag_t     *pag;
 
-       /* Calculate how much should be reserved for inodes to meet
-        * the max inode percentage.
+       /*
+        * Calculate how much should be reserved for inodes to meet
+        * the max inode percentage.  Used only for inode32.
         */
        if (mp->m_maxicount) {
                __uint64_t      icount;
@@ -610,54 +622,48 @@ xfs_set_inode32(struct xfs_mount *mp, xfs_agnumber_t agcount)
                max_metadata = agcount;
        }
 
+       /* Get the last possible inode in the filesystem */
        agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
+       ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
+
+       /*
+        * If user asked for no more than 32-bit inodes, and the fs is
+        * sufficiently large, set XFS_MOUNT_32BITINODES if we must alter
+        * the allocator to accommodate the request.
+        */
+       if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
+               mp->m_flags |= XFS_MOUNT_32BITINODES;
+       else
+               mp->m_flags &= ~XFS_MOUNT_32BITINODES;
 
        for (index = 0; index < agcount; index++) {
-               ino = XFS_AGINO_TO_INO(mp, index, agino);
+               struct xfs_perag        *pag;
 
-               if (ino > XFS_MAXINUMBER_32) {
-                       pag = xfs_perag_get(mp, index);
-                       pag->pagi_inodeok = 0;
-                       pag->pagf_metadata = 0;
-                       xfs_perag_put(pag);
-                       continue;
-               }
+               ino = XFS_AGINO_TO_INO(mp, index, agino);
 
                pag = xfs_perag_get(mp, index);
-               pag->pagi_inodeok = 1;
-               maxagi++;
-               if (index < max_metadata)
-                       pag->pagf_metadata = 1;
-               xfs_perag_put(pag);
-       }
-       mp->m_flags |= (XFS_MOUNT_32BITINODES |
-                       XFS_MOUNT_SMALL_INUMS);
 
-       return maxagi;
-}
-
-xfs_agnumber_t
-xfs_set_inode64(struct xfs_mount *mp, xfs_agnumber_t agcount)
-{
-       xfs_agnumber_t index = 0;
-
-       for (index = 0; index < agcount; index++) {
-               struct xfs_perag        *pag;
+               if (mp->m_flags & XFS_MOUNT_32BITINODES) {
+                       if (ino > XFS_MAXINUMBER_32) {
+                               pag->pagi_inodeok = 0;
+                               pag->pagf_metadata = 0;
+                       } else {
+                               pag->pagi_inodeok = 1;
+                               maxagi++;
+                               if (index < max_metadata)
+                                       pag->pagf_metadata = 1;
+                               else
+                                       pag->pagf_metadata = 0;
+                       }
+               } else {
+                       pag->pagi_inodeok = 1;
+                       pag->pagf_metadata = 0;
+               }
 
-               pag = xfs_perag_get(mp, index);
-               pag->pagi_inodeok = 1;
-               pag->pagf_metadata = 0;
                xfs_perag_put(pag);
        }
 
-       /* There is no need for lock protection on m_flags,
-        * the rw_semaphore of the VFS superblock is locked
-        * during mount/umount/remount operations, so this is
-        * enough to avoid concurency on the m_flags field
-        */
-       mp->m_flags &= ~(XFS_MOUNT_32BITINODES |
-                        XFS_MOUNT_SMALL_INUMS);
-       return index;
+       return (mp->m_flags & XFS_MOUNT_32BITINODES) ? maxagi : agcount;
 }
 
 STATIC int
@@ -1227,10 +1233,12 @@ xfs_fs_remount(
                        mp->m_flags &= ~XFS_MOUNT_BARRIER;
                        break;
                case Opt_inode64:
-                       mp->m_maxagi = xfs_set_inode64(mp, sbp->sb_agcount);
+                       mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;
+                       mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);
                        break;
                case Opt_inode32:
-                       mp->m_maxagi = xfs_set_inode32(mp, sbp->sb_agcount);
+                       mp->m_flags |= XFS_MOUNT_SMALL_INUMS;
+                       mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);
                        break;
                default:
                        /*

diff --git a/fs/xfs/xfs_super.h b/fs/xfs/xfs_super.h
index 499058f..2dfb1ce 100644 (file)
--- a/fs/xfs/xfs_super.h
+++ b/fs/xfs/xfs_super.h
@@ -65,8 +65,8 @@ extern __uint64_t xfs_max_file_offset(unsigned int);
 
 extern void xfs_flush_inodes(struct xfs_mount *mp);
 extern void xfs_blkdev_issue_flush(struct xfs_buftarg *);
-extern xfs_agnumber_t xfs_set_inode32(struct xfs_mount *, xfs_agnumber_t agcount);
-extern xfs_agnumber_t xfs_set_inode64(struct xfs_mount *, xfs_agnumber_t agcount);
+extern xfs_agnumber_t xfs_set_inode_alloc(struct xfs_mount *,
+                                          xfs_agnumber_t agcount);
 
 extern const struct export_operations xfs_export_operations;
 extern const struct xattr_handler *xfs_xattr_handlers[];