1 files changed, 218 insertions, 19 deletions

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index a96bde6df96d..a66b39805176 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -202,6 +202,27 @@ xfs_mount_free(
         kmem_free(mp, sizeof(xfs_mount_t));
 }
 
+/*
+ * Check size of device based on the (data/realtime) block count.
+ * Note: this check is used by the growfs code as well as mount.
+ */
+int
+xfs_sb_validate_fsb_count(
+        xfs_sb_t        *sbp,
+        __uint64_t      nblocks)
+{
+        ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
+        ASSERT(sbp->sb_blocklog >= BBSHIFT);
+
+#if XFS_BIG_BLKNOS     /* Limited by ULONG_MAX of page cache index */
+        if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
+                return E2BIG;
+#else                  /* Limited by UINT_MAX of sectors */
+        if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
+                return E2BIG;
+#endif
+        return 0;
+}
 
 /*
  * Check the validity of the SB found.
@@ -284,18 +305,8 @@ xfs_mount_validate_sb(
                 return XFS_ERROR(EFSCORRUPTED);
         }
 
-        ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
-        ASSERT(sbp->sb_blocklog >= BBSHIFT);
-
-#if XFS_BIG_BLKNOS     /* Limited by ULONG_MAX of page cache index */
-        if (unlikely(
-            (sbp->sb_dblocks >> (PAGE_SHIFT - sbp->sb_blocklog)) > ULONG_MAX ||
-            (sbp->sb_rblocks >> (PAGE_SHIFT - sbp->sb_blocklog)) > ULONG_MAX)) {
-#else                  /* Limited by UINT_MAX of sectors */
-        if (unlikely(
-            (sbp->sb_dblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX ||
-            (sbp->sb_rblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX)) {
-#endif
+        if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
+            xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
                 xfs_fs_mount_cmn_err(flags,
                         "file system too large to be mounted on this system.");
                 return XFS_ERROR(E2BIG);
@@ -632,6 +643,64 @@ xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
                                         sbp->sb_inopblock);
         mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
 }
+
+/*
+ * xfs_initialize_perag_data
+ *
+ * Read in each per-ag structure so we can count up the number of
+ * allocated inodes, free inodes and used filesystem blocks as this
+ * information is no longer persistent in the superblock. Once we have
+ * this information, write it into the in-core superblock structure.
+ */
+STATIC int
+xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
+{
+        xfs_agnumber_t  index;
+        xfs_perag_t     *pag;
+        xfs_sb_t        *sbp = &mp->m_sb;
+        uint64_t        ifree = 0;
+        uint64_t        ialloc = 0;
+        uint64_t        bfree = 0;
+        uint64_t        bfreelst = 0;
+        uint64_t        btree = 0;
+        int             error;
+        int             s;
+
+        for (index = 0; index < agcount; index++) {
+                /*
+                 * read the agf, then the agi. This gets us
+                 * all the inforamtion we need and populates the
+                 * per-ag structures for us.
+                 */
+                error = xfs_alloc_pagf_init(mp, NULL, index, 0);
+                if (error)
+                        return error;
+
+                error = xfs_ialloc_pagi_init(mp, NULL, index);
+                if (error)
+                        return error;
+                pag = &mp->m_perag[index];
+                ifree += pag->pagi_freecount;
+                ialloc += pag->pagi_count;
+                bfree += pag->pagf_freeblks;
+                bfreelst += pag->pagf_flcount;
+                btree += pag->pagf_btreeblks;
+        }
+        /*
+         * Overwrite incore superblock counters with just-read data
+         */
+        s = XFS_SB_LOCK(mp);
+        sbp->sb_ifree = ifree;
+        sbp->sb_icount = ialloc;
+        sbp->sb_fdblocks = bfree + bfreelst + btree;
+        XFS_SB_UNLOCK(mp, s);
+
+        /* Fixup the per-cpu counters as well. */
+        xfs_icsb_reinit_counters(mp);
+
+        return 0;
+}
+
 /*
  * xfs_mountfs
  *
@@ -656,7 +725,7 @@ xfs_mountfs(
         bhv_vnode_t     *rvp = NULL;
         int             readio_log, writeio_log;
         xfs_daddr_t     d;
-        __uint64_t      ret64;
+        __uint64_t      resblks;
         __int64_t       update_flags;
         uint            quotamount, quotaflags;
         int             agno;
@@ -773,6 +842,7 @@ xfs_mountfs(
          */
         if ((mfsi_flags & XFS_MFSI_SECOND) == 0 &&
             (mp->m_flags & XFS_MOUNT_NOUUID) == 0) {
+                __uint64_t      ret64;
                 if (xfs_uuid_mount(mp)) {
                         error = XFS_ERROR(EINVAL);
                         goto error1;
@@ -976,6 +1046,34 @@ xfs_mountfs(
         }
 
         /*
+         * Now the log is mounted, we know if it was an unclean shutdown or
+         * not. If it was, with the first phase of recovery has completed, we
+         * have consistent AG blocks on disk. We have not recovered EFIs yet,
+         * but they are recovered transactionally in the second recovery phase
+         * later.
+         *
+         * Hence we can safely re-initialise incore superblock counters from
+         * the per-ag data. These may not be correct if the filesystem was not
+         * cleanly unmounted, so we need to wait for recovery to finish before
+         * doing this.
+         *
+         * If the filesystem was cleanly unmounted, then we can trust the
+         * values in the superblock to be correct and we don't need to do
+         * anything here.
+         *
+         * If we are currently making the filesystem, the initialisation will
+         * fail as the perag data is in an undefined state.
+         */
+
+        if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
+            !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
+             !mp->m_sb.sb_inprogress) {
+                error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
+                if (error) {
+                        goto error2;
+                }
+        }
+        /*
          * Get and sanity-check the root inode.
          * Save the pointer to it in the mount structure.
          */
@@ -1044,6 +1142,23 @@ xfs_mountfs(
         if ((error = XFS_QM_MOUNT(mp, quotamount, quotaflags, mfsi_flags)))
                 goto error4;
 
+        /*
+         * Now we are mounted, reserve a small amount of unused space for
+         * privileged transactions. This is needed so that transaction
+         * space required for critical operations can dip into this pool
+         * when at ENOSPC. This is needed for operations like create with
+         * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
+         * are not allowed to use this reserved space.
+         *
+         * We default to 5% or 1024 fsbs of space reserved, whichever is smaller.
+         * This may drive us straight to ENOSPC on mount, but that implies
+         * we were already there on the last unmount.
+         */
+        resblks = mp->m_sb.sb_dblocks;
+        do_div(resblks, 20);
+        resblks = min_t(__uint64_t, resblks, 1024);
+        xfs_reserve_blocks(mp, &resblks, NULL);
+
         return 0;
 
  error4:
@@ -1083,7 +1198,19 @@ xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
 #if defined(DEBUG) || defined(INDUCE_IO_ERROR)
         int64_t         fsid;
 #endif
+        __uint64_t      resblks;
 
+        /*
+         * We can potentially deadlock here if we have an inode cluster
+         * that has been freed has it's buffer still pinned in memory because
+         * the transaction is still sitting in a iclog. The stale inodes
+         * on that buffer will have their flush locks held until the
+         * transaction hits the disk and the callbacks run. the inode
+         * flush takes the flush lock unconditionally and with nothing to
+         * push out the iclog we will never get that unlocked. hence we
+         * need to force the log first.
+         */
+        xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE | XFS_LOG_SYNC);
         xfs_iflush_all(mp);
 
         XFS_QM_DQPURGEALL(mp, XFS_QMOPT_QUOTALL | XFS_QMOPT_UMOUNTING);
@@ -1100,10 +1227,26 @@ xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
                 xfs_binval(mp->m_rtdev_targp);
         }
 
-        xfs_unmountfs_writesb(mp);
+        /*
+         * Unreserve any blocks we have so that when we unmount we don't account
+         * the reserved free space as used. This is really only necessary for
+         * lazy superblock counting because it trusts the incore superblock
+         * counters to be aboslutely correct on clean unmount.
+         *
+         * We don't bother correcting this elsewhere for lazy superblock
+         * counting because on mount of an unclean filesystem we reconstruct the
+         * correct counter value and this is irrelevant.
+         *
+         * For non-lazy counter filesystems, this doesn't matter at all because
+         * we only every apply deltas to the superblock and hence the incore
+         * value does not matter....
+         */
+        resblks = 0;
+        xfs_reserve_blocks(mp, &resblks, NULL);
 
+        xfs_log_sbcount(mp, 1);
+        xfs_unmountfs_writesb(mp);
         xfs_unmountfs_wait(mp);                 /* wait for async bufs */
-
         xfs_log_unmount(mp);                    /* Done! No more fs ops. */
 
         xfs_freesb(mp);
@@ -1150,6 +1293,62 @@ xfs_unmountfs_wait(xfs_mount_t *mp)
 }
 
 int
+xfs_fs_writable(xfs_mount_t *mp)
+{
+        bhv_vfs_t       *vfsp = XFS_MTOVFS(mp);
+
+        return !(vfs_test_for_freeze(vfsp) || XFS_FORCED_SHUTDOWN(mp) ||
+                (vfsp->vfs_flag & VFS_RDONLY));
+}
+
+/*
+ * xfs_log_sbcount
+ *
+ * Called either periodically to keep the on disk superblock values
+ * roughly up to date or from unmount to make sure the values are
+ * correct on a clean unmount.
+ *
+ * Note this code can be called during the process of freezing, so
+ * we may need to use the transaction allocator which does not not
+ * block when the transaction subsystem is in its frozen state.
+ */
+int
+xfs_log_sbcount(
+        xfs_mount_t     *mp,
+        uint            sync)
+{
+        xfs_trans_t     *tp;
+        int             error;
+
+        if (!xfs_fs_writable(mp))
+                return 0;
+
+        xfs_icsb_sync_counters(mp);
+
+        /*
+         * we don't need to do this if we are updating the superblock
+         * counters on every modification.
+         */
+        if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
+                return 0;
+
+        tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT);
+        error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+                                        XFS_DEFAULT_LOG_COUNT);
+        if (error) {
+                xfs_trans_cancel(tp, 0);
+                return error;
+        }
+
+        xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
+        if (sync)
+                xfs_trans_set_sync(tp);
+        xfs_trans_commit(tp, 0);
+
+        return 0;
+}
+
+int
 xfs_unmountfs_writesb(xfs_mount_t *mp)
 {
         xfs_buf_t       *sbp;
@@ -1160,16 +1359,15 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
          * skip superblock write if fs is read-only, or
          * if we are doing a forced umount.
          */
-        sbp = xfs_getsb(mp, 0);
         if (!(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY ||
                 XFS_FORCED_SHUTDOWN(mp))) {
 
-                xfs_icsb_sync_counters(mp);
+                sbp = xfs_getsb(mp, 0);
+                sb = XFS_BUF_TO_SBP(sbp);
 
                 /*
                  * mark shared-readonly if desired
                  */
-                sb = XFS_BUF_TO_SBP(sbp);
                 if (mp->m_mk_sharedro) {
                         if (!(sb->sb_flags & XFS_SBF_READONLY))
                                 sb->sb_flags |= XFS_SBF_READONLY;
@@ -1178,6 +1376,7 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
                         xfs_fs_cmn_err(CE_NOTE, mp,
                                 "Unmounting, marking shared read-only");
                 }
+
                 XFS_BUF_UNDONE(sbp);
                 XFS_BUF_UNREAD(sbp);
                 XFS_BUF_UNDELAYWRITE(sbp);
@@ -1192,8 +1391,8 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
                                           mp, sbp, XFS_BUF_ADDR(sbp));
                 if (error && mp->m_mk_sharedro)
                         xfs_fs_cmn_err(CE_ALERT, mp, "Superblock write error detected while unmounting.  Filesystem may not be marked shared readonly");
+                xfs_buf_relse(sbp);
         }
-        xfs_buf_relse(sbp);
         return error;
 }