From f11459ad7dab9e9eb5a05b8bd3bec338ea8f485d Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 16 Aug 2010 01:54:52 +0900 Subject: nilfs2: do not allocate multiple super block instances for a device This stops allocating multiple super block instances for a device. All snapshots and a current mode mount (i.e. latest tree) will be controlled with nilfs_root objects that are kept within an sb instance. nilfs_get_sb() is rewritten so that it always has a root object for the latest tree and snapshots make additional root objects. The root dentry of the latest tree is binded to sb->s_root even if it isn't attached on a directory. Root dentries of snapshots or the latest tree are binded to mnt->mnt_root on which they are mounted. With this patch, nilfs_find_sbinfo() function, nilfs->ns_supers list, and nilfs->ns_current back pointer, are deleted. In addition, init_nilfs() and load_nilfs() are simplified since they will be called once for a device, not repeatedly called for mount points. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/the_nilfs.c | 89 +-------------------------------------------------- 1 file changed, 1 insertion(+), 88 deletions(-) (limited to 'fs/nilfs2/the_nilfs.c') diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c index 89c78562d0e9..960c28797bb2 100644 --- a/fs/nilfs2/the_nilfs.c +++ b/fs/nilfs2/the_nilfs.c @@ -82,11 +82,9 @@ static struct the_nilfs *alloc_nilfs(struct block_device *bdev) atomic_set(&nilfs->ns_count, 1); atomic_set(&nilfs->ns_ndirtyblks, 0); init_rwsem(&nilfs->ns_sem); - init_rwsem(&nilfs->ns_super_sem); mutex_init(&nilfs->ns_mount_mutex); init_rwsem(&nilfs->ns_writer_sem); INIT_LIST_HEAD(&nilfs->ns_list); - INIT_LIST_HEAD(&nilfs->ns_supers); INIT_LIST_HEAD(&nilfs->ns_gc_inodes); spin_lock_init(&nilfs->ns_last_segment_lock); nilfs->ns_cptree = RB_ROOT; @@ -307,15 +305,6 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) int valid_fs = nilfs_valid_fs(nilfs); int err; - if (nilfs_loaded(nilfs)) { - if (valid_fs || - ((s_flags & MS_RDONLY) && nilfs_test_opt(sbi, NORECOVERY))) - return 0; - printk(KERN_ERR "NILFS: the filesystem is in an incomplete " - "recovery state.\n"); - return -EINVAL; - } - if (!valid_fs) { printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); if (s_flags & MS_RDONLY) { @@ -632,12 +621,7 @@ static int nilfs_load_super_block(struct the_nilfs *nilfs, * * init_nilfs() performs common initialization per block device (e.g. * reading the super block, getting disk layout information, initializing - * shared fields in the_nilfs). It takes on some portion of the jobs - * typically done by a fill_super() routine. This division arises from - * the nature that multiple NILFS instances may be simultaneously - * mounted on a device. - * For multiple mounts on the same device, only the first mount - * invokes these tasks. + * shared fields in the_nilfs). * * Return Value: On success, 0 is returned. On error, a negative error * code is returned. @@ -651,27 +635,6 @@ int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data) int err; down_write(&nilfs->ns_sem); - if (nilfs_init(nilfs)) { - /* Load values from existing the_nilfs */ - sbp = nilfs->ns_sbp[0]; - err = nilfs_store_magic_and_option(sb, sbp, data); - if (err) - goto out; - - err = nilfs_check_feature_compatibility(sb, sbp); - if (err) - goto out; - - blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); - if (sb->s_blocksize != blocksize && - !sb_set_blocksize(sb, blocksize)) { - printk(KERN_ERR "NILFS: blocksize %d unfit to device\n", - blocksize); - err = -EINVAL; - } - sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); - goto out; - } blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); if (!blocksize) { @@ -901,56 +864,6 @@ void nilfs_put_root(struct nilfs_root *root) } } -/** - * 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_super_sem); - /* - * The SNAPSHOT flag and sb->s_flags are supposed to be - * protected with nilfs->ns_super_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_super_sem); - return NULL; - - found: - atomic_inc(&sbi->s_count); - up_read(&nilfs->ns_super_sem); - return sbi; -} - int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno, int snapshot_mount) { -- cgit v1.2.3