From d5db0f97fbbeff11c88dec1aaf1536a975afbaeb Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@sandeen.net>
Date: Fri, 5 Feb 2010 22:59:53 +0000
Subject: [PATCH] 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>
---
fs/xfs/linux-2.6/xfs_ioctl.c | 3 +++
fs/xfs/linux-2.6/xfs_super.c | 51 ++++++++++++++++++++++++++----------
fs/xfs/xfs_mount.c | 34 ++++++++++++++++--------
fs/xfs/xfs_mount.h | 1 +
4 files changed, 64 insertions(+), 25 deletions(-)
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 3906e85abfdc..4ea1ee18aded 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -1431,6 +1431,9 @@ xfs_file_ioctl(
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
+ if (mp->m_flags & XFS_MOUNT_RDONLY)
+ return -XFS_ERROR(EROFS);
+
if (copy_from_user(&inout, arg, sizeof(inout)))
return -XFS_ERROR(EFAULT);
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index e9c21454b9e2..6ce828e0e17b 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -1256,6 +1256,29 @@ xfs_fs_statfs(
return 0;
}
+STATIC void
+xfs_save_resvblks(struct xfs_mount *mp)
+{
+ __uint64_t resblks = 0;
+
+ mp->m_resblks_save = mp->m_resblks;
+ xfs_reserve_blocks(mp, &resblks, NULL);
+}
+
+STATIC void
+xfs_restore_resvblks(struct xfs_mount *mp)
+{
+ __uint64_t resblks;
+
+ if (mp->m_resblks_save) {
+ resblks = mp->m_resblks_save;
+ mp->m_resblks_save = 0;
+ } else
+ resblks = xfs_default_resblks(mp);
+
+ xfs_reserve_blocks(mp, &resblks, NULL);
+}
+
STATIC int
xfs_fs_remount(
struct super_block *sb,
@@ -1318,8 +1341,6 @@ xfs_fs_remount(
/* ro -> rw */
if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(*flags & MS_RDONLY)) {
- __uint64_t resblks;
-
mp->m_flags &= ~XFS_MOUNT_RDONLY;
if (mp->m_flags & XFS_MOUNT_BARRIER)
xfs_mountfs_check_barriers(mp);
@@ -1342,15 +1363,7 @@ xfs_fs_remount(
* Fill out the reserve pool if it is empty. Use the stashed
* value if it is non-zero, otherwise go with the default.
*/
- if (mp->m_resblks_save) {
- resblks = mp->m_resblks_save;
- mp->m_resblks_save = 0;
- } else {
- resblks = mp->m_sb.sb_dblocks;
- do_div(resblks, 20);
- resblks = min_t(__uint64_t, resblks, 1024);
- }
- xfs_reserve_blocks(mp, &resblks, NULL);
+ xfs_restore_resvblks(mp);
}
/* rw -> ro */
@@ -1363,11 +1376,9 @@ xfs_fs_remount(
* so that if we get remounted rw, we can return it to the same
* size.
*/
- __uint64_t resblks = 0;
xfs_quiesce_data(mp);
- mp->m_resblks_save = mp->m_resblks;
- xfs_reserve_blocks(mp, &resblks, NULL);
+ xfs_save_resvblks(mp);
xfs_quiesce_attr(mp);
mp->m_flags |= XFS_MOUNT_RDONLY;
}
@@ -1386,10 +1397,21 @@ xfs_fs_freeze(
{
struct xfs_mount *mp = XFS_M(sb);
+ xfs_save_resvblks(mp);
xfs_quiesce_attr(mp);
return -xfs_fs_log_dummy(mp);
}
+STATIC int
+xfs_fs_unfreeze(
+ struct super_block *sb)
+{
+ struct xfs_mount *mp = XFS_M(sb);
+
+ xfs_restore_resvblks(mp);
+ return 0;
+}
+
STATIC int
xfs_fs_show_options(
struct seq_file *m,
@@ -1612,6 +1634,7 @@ static const struct super_operations xfs_super_operations = {
.put_super = xfs_fs_put_super,
.sync_fs = xfs_fs_sync_fs,
.freeze_fs = xfs_fs_freeze,
+ .unfreeze_fs = xfs_fs_unfreeze,
.statfs = xfs_fs_statfs,
.remount_fs = xfs_fs_remount,
.show_options = xfs_fs_show_options,
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 7f81ed72c875..5061149b2cc4 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1091,6 +1091,22 @@ xfs_mount_reset_sbqflags(
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 @@ xfs_mountfs(
* 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;
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 02d45f213e58..70504fcf14cd 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -421,6 +421,7 @@ typedef struct xfs_mod_sb {
} xfs_mod_sb_t;
extern int xfs_log_sbcount(xfs_mount_t *, uint);
+extern __uint64_t xfs_default_resblks(xfs_mount_t *mp);
extern int xfs_mountfs(xfs_mount_t *mp);
extern void xfs_unmountfs(xfs_mount_t *);