xfs: more reserved blocks fixups
This mangles the reserved blocks counts a little more.
1) add a helper function for the default reserved count
2) add helper functions to save/restore counts on ro/rw
3) save/restore reserved blocks on freeze/thaw
4) disallow changing reserved count while readonly
V2: changed field name to match Dave's changes
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 7f81ed7..5061149 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1091,6 +1091,22 @@
return xfs_trans_commit(tp, 0);
}
+__uint64_t
+xfs_default_resblks(xfs_mount_t *mp)
+{
+ __uint64_t resblks;
+
+ /*
+ * 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. Warn if this occurs.
+ */
+ resblks = mp->m_sb.sb_dblocks;
+ do_div(resblks, 20);
+ resblks = min_t(__uint64_t, resblks, 1024);
+ return resblks;
+}
+
/*
* This function does the following on an initial mount of a file system:
* - reads the superblock from disk and init the mount struct
@@ -1401,18 +1417,14 @@
* 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. Warn if this occurs.
*/
- resblks = mp->m_sb.sb_dblocks;
- do_div(resblks, 20);
- resblks = min_t(__uint64_t, resblks, 1024);
- error = xfs_reserve_blocks(mp, &resblks, NULL);
- if (error)
- cmn_err(CE_WARN, "XFS: Unable to allocate reserve blocks. "
- "Continuing without a reserve pool.");
+ if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
+ resblks = xfs_default_resblks(mp);
+ error = xfs_reserve_blocks(mp, &resblks, NULL);
+ if (error)
+ cmn_err(CE_WARN, "XFS: Unable to allocate reserve "
+ "blocks. Continuing without a reserve pool.");
+ }
return 0;