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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-06-08 01:39:31 +0900
committerAl Viro <viro@zeniv.linux.org.uk>2009-06-11 21:36:18 -0400
commit6dd4740662405a68bb229ac2b9e0aeaaf2188bf2 (patch)
tree36e6ae2a095613be1c36e8828ee9471e60c09de6 /fs/nilfs2/the_nilfs.c
parent3f82ff55168e92859119bf348e9e0bd6714d2fea (diff)
nilfs2: simplify remaining sget() use
This simplifies the test function passed on the remaining sget() callsite in nilfs. Instead of checking mount type (i.e. ro-mount/rw-mount/snapshot mount) in the test function passed to sget(), this patch first looks up the nilfs_sb_info struct which the given mount type matches, and then acquires the super block instance holding the nilfs_sb_info. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/nilfs2/the_nilfs.c')
-rw-r--r--fs/nilfs2/the_nilfs.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 45dbf6a6174..221953bfc85 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -664,6 +664,56 @@ int nilfs_near_disk_full(struct the_nilfs *nilfs)
return ret;
}
+/**
+ * nilfs_find_sbinfo - find existing nilfs_sb_info structure
+ * @nilfs: nilfs object
+ * @rw_mount: mount type (non-zero value for read/write mount)
+ * @cno: checkpoint number (zero for read-only mount)
+ *
+ * nilfs_find_sbinfo() returns the nilfs_sb_info structure which
+ * @rw_mount and @cno (in case of snapshots) matched. If no instance
+ * was found, NULL is returned. Although the super block instance can
+ * be unmounted after this function returns, the nilfs_sb_info struct
+ * is kept on memory until nilfs_put_sbinfo() is called.
+ */
+struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *nilfs,
+ int rw_mount, __u64 cno)
+{
+ struct nilfs_sb_info *sbi;
+
+ down_read(&nilfs->ns_sem);
+ /*
+ * The SNAPSHOT flag and sb->s_flags are supposed to be
+ * protected with nilfs->ns_sem.
+ */
+ sbi = nilfs->ns_current;
+ if (rw_mount) {
+ if (sbi && !(sbi->s_super->s_flags & MS_RDONLY))
+ goto found; /* read/write mount */
+ else
+ goto out;
+ } else if (cno == 0) {
+ if (sbi && (sbi->s_super->s_flags & MS_RDONLY))
+ goto found; /* read-only mount */
+ else
+ goto out;
+ }
+
+ list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
+ if (nilfs_test_opt(sbi, SNAPSHOT) &&
+ sbi->s_snapshot_cno == cno)
+ goto found; /* snapshot mount */
+ }
+ out:
+ up_read(&nilfs->ns_sem);
+ return NULL;
+
+ found:
+ atomic_inc(&sbi->s_count);
+ up_read(&nilfs->ns_sem);
+ return sbi;
+}
+
int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
int snapshot_mount)
{