GFS2: Clean up freeze code

The freeze code has not been looked at a lot recently. Upstream has
moved on, and this is an attempt to catch us back up again. There
is a vfs level interface for the freeze code which can be called
from our (obsolete, but kept for backward compatibility purposes)
sysfs freeze interface. This means freezing this way vs. doing it
from the ioctl should now work in identical fashion.

As a result of this, the freeze function is only called once
and we can drop our own special purpose code for counting the
number of freezes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 5d129ab89733f2bc29e8c639cff455fe372b6717..19750bcb1ce7f738c42cdcb40f0c8f5d5f586c54 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -757,10 +757,7 @@ struct gfs2_sbd {
        unsigned int sd_replayed_blocks;
 
        /* For quiescing the filesystem */
-
        struct gfs2_holder sd_freeze_gh;
-       struct mutex sd_freeze_lock;
-       unsigned int sd_freeze_count;
 
        char sd_fsname[GFS2_FSNAME_LEN];
        char sd_table_name[GFS2_FSNAME_LEN];

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 0e3554edb8f25d2f5d82932294eca6b5b4d54020..5f5aba529fb16c70b3a6cbbf183af56225e8b5ba 100644 (file)
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -115,8 +115,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 
        INIT_LIST_HEAD(&sdp->sd_revoke_list);
 
-       mutex_init(&sdp->sd_freeze_lock);
-
        return sdp;
 }
 

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 4dfda4c946349fa4a1c9126dd82785385845cfd0..c075b62aef598ba8cda94592518671b71b701560 100644 (file)
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -663,54 +663,6 @@ out:
        return error;
 }
 
-/**
- * gfs2_freeze_fs - freezes the file system
- * @sdp: the file system
- *
- * This function flushes data and meta data for all machines by
- * acquiring the transaction log exclusively.  All journals are
- * ensured to be in a clean state as well.
- *
- * Returns: errno
- */
-
-int gfs2_freeze_fs(struct gfs2_sbd *sdp)
-{
-       int error = 0;
-
-       mutex_lock(&sdp->sd_freeze_lock);
-
-       if (!sdp->sd_freeze_count++) {
-               error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
-               if (error)
-                       sdp->sd_freeze_count--;
-       }
-
-       mutex_unlock(&sdp->sd_freeze_lock);
-
-       return error;
-}
-
-/**
- * gfs2_unfreeze_fs - unfreezes the file system
- * @sdp: the file system
- *
- * This function allows the file system to proceed by unlocking
- * the exclusively held transaction lock.  Other GFS2 nodes are
- * now free to acquire the lock shared and go on with their lives.
- *
- */
-
-void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
-{
-       mutex_lock(&sdp->sd_freeze_lock);
-
-       if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
-               gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
-
-       mutex_unlock(&sdp->sd_freeze_lock);
-}
-
 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
 {
        struct gfs2_dinode *str = buf;
@@ -888,13 +840,6 @@ static void gfs2_put_super(struct super_block *sb)
        int error;
        struct gfs2_jdesc *jd;
 
-       /*  Unfreeze the filesystem, if we need to  */
-
-       mutex_lock(&sdp->sd_freeze_lock);
-       if (sdp->sd_freeze_count)
-               gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
-       mutex_unlock(&sdp->sd_freeze_lock);
-
        /* No more recovery requests */
        set_bit(SDF_NORECOVERY, &sdp->sd_flags);
        smp_mb();
@@ -985,7 +930,7 @@ static int gfs2_freeze(struct super_block *sb)
                return -EINVAL;
 
        for (;;) {
-               error = gfs2_freeze_fs(sdp);
+               error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
                if (!error)
                        break;
 
@@ -1013,7 +958,9 @@ static int gfs2_freeze(struct super_block *sb)
 
 static int gfs2_unfreeze(struct super_block *sb)
 {
-       gfs2_unfreeze_fs(sb->s_fs_info);
+       struct gfs2_sbd *sdp = sb->s_fs_info;
+
+       gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
        return 0;
 }
 

diff --git a/fs/gfs2/super.h b/fs/gfs2/super.h
index a0464680af0b8cec6b7fdf2c69099ba740933dce..90e3322ffa10ab4564195aa22ba156262dc304ff 100644 (file)
--- a/fs/gfs2/super.h
+++ b/fs/gfs2/super.h
@@ -46,9 +46,6 @@ extern void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
                          struct buffer_head *l_bh);
 extern int gfs2_statfs_sync(struct super_block *sb, int type);
 
-extern int gfs2_freeze_fs(struct gfs2_sbd *sdp);
-extern void gfs2_unfreeze_fs(struct gfs2_sbd *sdp);
-
 extern struct file_system_type gfs2_fs_type;
 extern struct file_system_type gfs2meta_fs_type;
 extern const struct export_operations gfs2_export_ops;

diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 8056b7b7238e9ee7770b21fd7cd5e77835c3062c..462e84142759b1690f5346201844e0ff6df4b7f7 100644 (file)
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -91,19 +91,15 @@ static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
 
 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
 {
-       unsigned int count;
-
-       mutex_lock(&sdp->sd_freeze_lock);
-       count = sdp->sd_freeze_count;
-       mutex_unlock(&sdp->sd_freeze_lock);
+       struct super_block *sb = sdp->sd_vfs;
+       int frozen = (sb->s_writers.frozen == SB_UNFROZEN) ? 0 : 1;
 
-       return snprintf(buf, PAGE_SIZE, "%u\n", count);
+       return snprintf(buf, PAGE_SIZE, "%u\n", frozen);
 }
 
 static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
 {
-       ssize_t ret = len;
-       int error = 0;
+       int error;
        int n = simple_strtol(buf, NULL, 0);
 
        if (!capable(CAP_SYS_ADMIN))
@@ -111,19 +107,21 @@ static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
 
        switch (n) {
        case 0:
-               gfs2_unfreeze_fs(sdp);
+               error = thaw_super(sdp->sd_vfs);
                break;
        case 1:
-               error = gfs2_freeze_fs(sdp);
+               error = freeze_super(sdp->sd_vfs);
                break;
        default:
-               ret = -EINVAL;
+               return -EINVAL;
        }
 
-       if (error)
+       if (error) {
                fs_warn(sdp, "freeze %d error %d", n, error);
+               return error;
+       }
 
-       return ret;
+       return len;
 }
 
 static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)