f2fs: add super block operations

This adds the implementation of superblock operations for f2fs, which includes
- init_f2fs_fs/exit_f2fs_fs
- f2fs_mount
- super_operations of f2fs

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 656 insertions, 0 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
new file mode 100644
index 000000000000..8661c93538af
--- /dev/null
+++ b/fs/f2fs/super.c
@@ -0,0 +1,656 @@
+/**
+ * fs/f2fs/super.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/statfs.h>
+#include <linux/proc_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/backing-dev.h>
+#include <linux/kthread.h>
+#include <linux/parser.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/random.h>
+#include <linux/exportfs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "xattr.h"
+
+static struct kmem_cache *f2fs_inode_cachep;
+
+enum {
+        Opt_gc_background_off,
+        Opt_disable_roll_forward,
+        Opt_discard,
+        Opt_noheap,
+        Opt_nouser_xattr,
+        Opt_noacl,
+        Opt_active_logs,
+        Opt_disable_ext_identify,
+        Opt_err,
+};
+
+static match_table_t f2fs_tokens = {
+        {Opt_gc_background_off, "background_gc_off"},
+        {Opt_disable_roll_forward, "disable_roll_forward"},
+        {Opt_discard, "discard"},
+        {Opt_noheap, "no_heap"},
+        {Opt_nouser_xattr, "nouser_xattr"},
+        {Opt_noacl, "noacl"},
+        {Opt_active_logs, "active_logs=%u"},
+        {Opt_disable_ext_identify, "disable_ext_identify"},
+        {Opt_err, NULL},
+};
+
+static void init_once(void *foo)
+{
+        struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
+
+        memset(fi, 0, sizeof(*fi));
+        inode_init_once(&fi->vfs_inode);
+}
+
+static struct inode *f2fs_alloc_inode(struct super_block *sb)
+{
+        struct f2fs_inode_info *fi;
+
+        fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_NOFS | __GFP_ZERO);
+        if (!fi)
+                return NULL;
+
+        init_once((void *) fi);
+
+        /* Initilize f2fs-specific inode info */
+        fi->vfs_inode.i_version = 1;
+        atomic_set(&fi->dirty_dents, 0);
+        fi->i_current_depth = 1;
+        fi->i_advise = 0;
+        rwlock_init(&fi->ext.ext_lock);
+
+        set_inode_flag(fi, FI_NEW_INODE);
+
+        return &fi->vfs_inode;
+}
+
+static void f2fs_i_callback(struct rcu_head *head)
+{
+        struct inode *inode = container_of(head, struct inode, i_rcu);
+        kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
+}
+
+void f2fs_destroy_inode(struct inode *inode)
+{
+        call_rcu(&inode->i_rcu, f2fs_i_callback);
+}
+
+static void f2fs_put_super(struct super_block *sb)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(sb);
+
+        f2fs_destroy_stats(sbi);
+        stop_gc_thread(sbi);
+
+        write_checkpoint(sbi, false, true);
+
+        iput(sbi->node_inode);
+        iput(sbi->meta_inode);
+
+        /* destroy f2fs internal modules */
+        destroy_node_manager(sbi);
+        destroy_segment_manager(sbi);
+
+        kfree(sbi->ckpt);
+
+        sb->s_fs_info = NULL;
+        brelse(sbi->raw_super_buf);
+        kfree(sbi);
+}
+
+int f2fs_sync_fs(struct super_block *sb, int sync)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(sb);
+        int ret = 0;
+
+        if (!sbi->s_dirty && !get_pages(sbi, F2FS_DIRTY_NODES))
+                return 0;
+
+        if (sync)
+                write_checkpoint(sbi, false, false);
+
+        return ret;
+}
+
+static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+        struct super_block *sb = dentry->d_sb;
+        struct f2fs_sb_info *sbi = F2FS_SB(sb);
+        u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+        block_t total_count, user_block_count, start_count, ovp_count;
+
+        total_count = le64_to_cpu(sbi->raw_super->block_count);
+        user_block_count = sbi->user_block_count;
+        start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
+        ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
+        buf->f_type = F2FS_SUPER_MAGIC;
+        buf->f_bsize = sbi->blocksize;
+
+        buf->f_blocks = total_count - start_count;
+        buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
+        buf->f_bavail = user_block_count - valid_user_blocks(sbi);
+
+        buf->f_files = valid_inode_count(sbi);
+        buf->f_ffree = sbi->total_node_count - valid_node_count(sbi);
+
+        buf->f_namelen = F2FS_MAX_NAME_LEN;
+        buf->f_fsid.val[0] = (u32)id;
+        buf->f_fsid.val[1] = (u32)(id >> 32);
+
+        return 0;
+}
+
+static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
+
+        if (test_opt(sbi, BG_GC))
+                seq_puts(seq, ",background_gc_on");
+        else
+                seq_puts(seq, ",background_gc_off");
+        if (test_opt(sbi, DISABLE_ROLL_FORWARD))
+                seq_puts(seq, ",disable_roll_forward");
+        if (test_opt(sbi, DISCARD))
+                seq_puts(seq, ",discard");
+        if (test_opt(sbi, NOHEAP))
+                seq_puts(seq, ",no_heap_alloc");
+#ifdef CONFIG_F2FS_FS_XATTR
+        if (test_opt(sbi, XATTR_USER))
+                seq_puts(seq, ",user_xattr");
+        else
+                seq_puts(seq, ",nouser_xattr");
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+        if (test_opt(sbi, POSIX_ACL))
+                seq_puts(seq, ",acl");
+        else
+                seq_puts(seq, ",noacl");
+#endif
+        if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
+                seq_puts(seq, ",disable_ext_indentify");
+
+        seq_printf(seq, ",active_logs=%u", sbi->active_logs);
+
+        return 0;
+}
+
+static struct super_operations f2fs_sops = {
+        .alloc_inode    = f2fs_alloc_inode,
+        .destroy_inode  = f2fs_destroy_inode,
+        .write_inode    = f2fs_write_inode,
+        .show_options   = f2fs_show_options,
+        .evict_inode    = f2fs_evict_inode,
+        .put_super      = f2fs_put_super,
+        .sync_fs        = f2fs_sync_fs,
+        .statfs         = f2fs_statfs,
+};
+
+static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
+                u64 ino, u32 generation)
+{
+        struct f2fs_sb_info *sbi = F2FS_SB(sb);
+        struct inode *inode;
+
+        if (ino < F2FS_ROOT_INO(sbi))
+                return ERR_PTR(-ESTALE);
+
+        /*
+         * f2fs_iget isn't quite right if the inode is currently unallocated!
+         * However f2fs_iget currently does appropriate checks to handle stale
+         * inodes so everything is OK.
+         */
+        inode = f2fs_iget(sb, ino);
+        if (IS_ERR(inode))
+                return ERR_CAST(inode);
+        if (generation && inode->i_generation != generation) {
+                /* we didn't find the right inode.. */
+                iput(inode);
+                return ERR_PTR(-ESTALE);
+        }
+        return inode;
+}
+
+static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+                int fh_len, int fh_type)
+{
+        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+                                    f2fs_nfs_get_inode);
+}
+
+static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+                int fh_len, int fh_type)
+{
+        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+                                    f2fs_nfs_get_inode);
+}
+
+static const struct export_operations f2fs_export_ops = {
+        .fh_to_dentry = f2fs_fh_to_dentry,
+        .fh_to_parent = f2fs_fh_to_parent,
+        .get_parent = f2fs_get_parent,
+};
+
+static int parse_options(struct f2fs_sb_info *sbi, char *options)
+{
+        substring_t args[MAX_OPT_ARGS];
+        char *p;
+        int arg = 0;
+
+        if (!options)
+                return 0;
+
+        while ((p = strsep(&options, ",")) != NULL) {
+                int token;
+                if (!*p)
+                        continue;
+                /*
+                 * Initialize args struct so we know whether arg was
+                 * found; some options take optional arguments.
+                 */
+                args[0].to = args[0].from = NULL;
+                token = match_token(p, f2fs_tokens, args);
+
+                switch (token) {
+                case Opt_gc_background_off:
+                        clear_opt(sbi, BG_GC);
+                        break;
+                case Opt_disable_roll_forward:
+                        set_opt(sbi, DISABLE_ROLL_FORWARD);
+                        break;
+                case Opt_discard:
+                        set_opt(sbi, DISCARD);
+                        break;
+                case Opt_noheap:
+                        set_opt(sbi, NOHEAP);
+                        break;
+#ifdef CONFIG_F2FS_FS_XATTR
+                case Opt_nouser_xattr:
+                        clear_opt(sbi, XATTR_USER);
+                        break;
+#else
+                case Opt_nouser_xattr:
+                        pr_info("nouser_xattr options not supported\n");
+                        break;
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+                case Opt_noacl:
+                        clear_opt(sbi, POSIX_ACL);
+                        break;
+#else
+                case Opt_noacl:
+                        pr_info("noacl options not supported\n");
+                        break;
+#endif
+                case Opt_active_logs:
+                        if (args->from && match_int(args, &arg))
+                                return -EINVAL;
+                        if (arg != 2 && arg != 4 && arg != 6)
+                                return -EINVAL;
+                        sbi->active_logs = arg;
+                        break;
+                case Opt_disable_ext_identify:
+                        set_opt(sbi, DISABLE_EXT_IDENTIFY);
+                        break;
+                default:
+                        return -EINVAL;
+                }
+        }
+        return 0;
+}
+
+static loff_t max_file_size(unsigned bits)
+{
+        loff_t result = ADDRS_PER_INODE;
+        loff_t leaf_count = ADDRS_PER_BLOCK;
+
+        /* two direct node blocks */
+        result += (leaf_count * 2);
+
+        /* two indirect node blocks */
+        leaf_count *= NIDS_PER_BLOCK;
+        result += (leaf_count * 2);
+
+        /* one double indirect node block */
+        leaf_count *= NIDS_PER_BLOCK;
+        result += leaf_count;
+
+        result <<= bits;
+        return result;
+}
+
+static int sanity_check_raw_super(struct f2fs_super_block *raw_super)
+{
+        unsigned int blocksize;
+
+        if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic))
+                return 1;
+
+        /* Currently, support only 4KB block size */
+        blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
+        if (blocksize != PAGE_CACHE_SIZE)
+                return 1;
+        if (le32_to_cpu(raw_super->log_sectorsize) !=
+                                        F2FS_LOG_SECTOR_SIZE)
+                return 1;
+        if (le32_to_cpu(raw_super->log_sectors_per_block) !=
+                                        F2FS_LOG_SECTORS_PER_BLOCK)
+                return 1;
+        return 0;
+}
+
+static int sanity_check_ckpt(struct f2fs_super_block *raw_super,
+                                struct f2fs_checkpoint *ckpt)
+{
+        unsigned int total, fsmeta;
+
+        total = le32_to_cpu(raw_super->segment_count);
+        fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
+        fsmeta += le32_to_cpu(raw_super->segment_count_sit);
+        fsmeta += le32_to_cpu(raw_super->segment_count_nat);
+        fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
+        fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
+
+        if (fsmeta >= total)
+                return 1;
+        return 0;
+}
+
+static void init_sb_info(struct f2fs_sb_info *sbi)
+{
+        struct f2fs_super_block *raw_super = sbi->raw_super;
+        int i;
+
+        sbi->log_sectors_per_block =
+                le32_to_cpu(raw_super->log_sectors_per_block);
+        sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
+        sbi->blocksize = 1 << sbi->log_blocksize;
+        sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+        sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
+        sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
+        sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
+        sbi->total_sections = le32_to_cpu(raw_super->section_count);
+        sbi->total_node_count =
+                (le32_to_cpu(raw_super->segment_count_nat) / 2)
+                        * sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
+        sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
+        sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
+        sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
+
+        for (i = 0; i < NR_COUNT_TYPE; i++)
+                atomic_set(&sbi->nr_pages[i], 0);
+}
+
+static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
+{
+        struct f2fs_sb_info *sbi;
+        struct f2fs_super_block *raw_super;
+        struct buffer_head *raw_super_buf;
+        struct inode *root;
+        long err = -EINVAL;
+        int i;
+
+        /* allocate memory for f2fs-specific super block info */
+        sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
+        if (!sbi)
+                return -ENOMEM;
+
+        /* set a temporary block size */
+        if (!sb_set_blocksize(sb, F2FS_BLKSIZE))
+                goto free_sbi;
+
+        /* read f2fs raw super block */
+        raw_super_buf = sb_bread(sb, 0);
+        if (!raw_super_buf) {
+                err = -EIO;
+                goto free_sbi;
+        }
+        raw_super = (struct f2fs_super_block *)
+                        ((char *)raw_super_buf->b_data + F2FS_SUPER_OFFSET);
+
+        /* init some FS parameters */
+        sbi->active_logs = NR_CURSEG_TYPE;
+
+        set_opt(sbi, BG_GC);
+
+#ifdef CONFIG_F2FS_FS_XATTR
+        set_opt(sbi, XATTR_USER);
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+        set_opt(sbi, POSIX_ACL);
+#endif
+        /* parse mount options */
+        if (parse_options(sbi, (char *)data))
+                goto free_sb_buf;
+
+        /* sanity checking of raw super */
+        if (sanity_check_raw_super(raw_super))
+                goto free_sb_buf;
+
+        sb->s_maxbytes = max_file_size(raw_super->log_blocksize);
+        sb->s_max_links = F2FS_LINK_MAX;
+        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+
+        sb->s_op = &f2fs_sops;
+        sb->s_xattr = f2fs_xattr_handlers;
+        sb->s_export_op = &f2fs_export_ops;
+        sb->s_magic = F2FS_SUPER_MAGIC;
+        sb->s_fs_info = sbi;
+        sb->s_time_gran = 1;
+        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+                (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+        memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
+
+        /* init f2fs-specific super block info */
+        sbi->sb = sb;
+        sbi->raw_super = raw_super;
+        sbi->raw_super_buf = raw_super_buf;
+        mutex_init(&sbi->gc_mutex);
+        mutex_init(&sbi->write_inode);
+        mutex_init(&sbi->writepages);
+        mutex_init(&sbi->cp_mutex);
+        for (i = 0; i < NR_LOCK_TYPE; i++)
+                mutex_init(&sbi->fs_lock[i]);
+        sbi->por_doing = 0;
+        spin_lock_init(&sbi->stat_lock);
+        init_rwsem(&sbi->bio_sem);
+        init_sb_info(sbi);
+
+        /* get an inode for meta space */
+        sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
+        if (IS_ERR(sbi->meta_inode)) {
+                err = PTR_ERR(sbi->meta_inode);
+                goto free_sb_buf;
+        }
+
+        err = get_valid_checkpoint(sbi);
+        if (err)
+                goto free_meta_inode;
+
+        /* sanity checking of checkpoint */
+        err = -EINVAL;
+        if (sanity_check_ckpt(raw_super, sbi->ckpt))
+                goto free_cp;
+
+        sbi->total_valid_node_count =
+                                le32_to_cpu(sbi->ckpt->valid_node_count);
+        sbi->total_valid_inode_count =
+                                le32_to_cpu(sbi->ckpt->valid_inode_count);
+        sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
+        sbi->total_valid_block_count =
+                                le64_to_cpu(sbi->ckpt->valid_block_count);
+        sbi->last_valid_block_count = sbi->total_valid_block_count;
+        sbi->alloc_valid_block_count = 0;
+        INIT_LIST_HEAD(&sbi->dir_inode_list);
+        spin_lock_init(&sbi->dir_inode_lock);
+
+        /* init super block */
+        if (!sb_set_blocksize(sb, sbi->blocksize))
+                goto free_cp;
+
+        init_orphan_info(sbi);
+
+        /* setup f2fs internal modules */
+        err = build_segment_manager(sbi);
+        if (err)
+                goto free_sm;
+        err = build_node_manager(sbi);
+        if (err)
+                goto free_nm;
+
+        build_gc_manager(sbi);
+
+        /* get an inode for node space */
+        sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
+        if (IS_ERR(sbi->node_inode)) {
+                err = PTR_ERR(sbi->node_inode);
+                goto free_nm;
+        }
+
+        /* if there are nt orphan nodes free them */
+        err = -EINVAL;
+        if (!(sbi->ckpt->ckpt_flags & CP_UMOUNT_FLAG) &&
+                                recover_orphan_inodes(sbi))
+                goto free_node_inode;
+
+        /* read root inode and dentry */
+        root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
+        if (IS_ERR(root)) {
+                err = PTR_ERR(root);
+                goto free_node_inode;
+        }
+        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size)
+                goto free_root_inode;
+
+        sb->s_root = d_make_root(root); /* allocate root dentry */
+        if (!sb->s_root) {
+                err = -ENOMEM;
+                goto free_root_inode;
+        }
+
+        /* recover fsynced data */
+        if (!(sbi->ckpt->ckpt_flags & CP_UMOUNT_FLAG) &&
+                                !test_opt(sbi, DISABLE_ROLL_FORWARD))
+                recover_fsync_data(sbi);
+
+        /* After POR, we can run background GC thread */
+        err = start_gc_thread(sbi);
+        if (err)
+                goto fail;
+
+        err = f2fs_build_stats(sbi);
+        if (err)
+                goto fail;
+
+        return 0;
+fail:
+        stop_gc_thread(sbi);
+free_root_inode:
+        dput(sb->s_root);
+        sb->s_root = NULL;
+free_node_inode:
+        iput(sbi->node_inode);
+free_nm:
+        destroy_node_manager(sbi);
+free_sm:
+        destroy_segment_manager(sbi);
+free_cp:
+        kfree(sbi->ckpt);
+free_meta_inode:
+        make_bad_inode(sbi->meta_inode);
+        iput(sbi->meta_inode);
+free_sb_buf:
+        brelse(raw_super_buf);
+free_sbi:
+        kfree(sbi);
+        return err;
+}
+
+static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
+                        const char *dev_name, void *data)
+{
+        return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
+}
+
+static struct file_system_type f2fs_fs_type = {
+        .owner          = THIS_MODULE,
+        .name           = "f2fs",
+        .mount          = f2fs_mount,
+        .kill_sb        = kill_block_super,
+        .fs_flags       = FS_REQUIRES_DEV,
+};
+
+static int init_inodecache(void)
+{
+        f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
+                        sizeof(struct f2fs_inode_info), NULL);
+        if (f2fs_inode_cachep == NULL)
+                return -ENOMEM;
+        return 0;
+}
+
+static void destroy_inodecache(void)
+{
+        /*
+         * Make sure all delayed rcu free inodes are flushed before we
+         * destroy cache.
+         */
+        rcu_barrier();
+        kmem_cache_destroy(f2fs_inode_cachep);
+}
+
+static int __init init_f2fs_fs(void)
+{
+        int err;
+
+        err = init_inodecache();
+        if (err)
+                goto fail;
+        err = create_node_manager_caches();
+        if (err)
+                goto fail;
+        err = create_gc_caches();
+        if (err)
+                goto fail;
+        err = create_checkpoint_caches();
+        if (err)
+                goto fail;
+        return register_filesystem(&f2fs_fs_type);
+fail:
+        return err;
+}
+
+static void __exit exit_f2fs_fs(void)
+{
+        destroy_root_stats();
+        unregister_filesystem(&f2fs_fs_type);
+        destroy_checkpoint_caches();
+        destroy_gc_caches();
+        destroy_node_manager_caches();
+        destroy_inodecache();
+}
+
+module_init(init_f2fs_fs)
+module_exit(exit_f2fs_fs)
+
+MODULE_AUTHOR("Samsung Electronics's Praesto Team");
+MODULE_DESCRIPTION("Flash Friendly File System");
+MODULE_LICENSE("GPL");