On Oct 23, 2012, at 6:27 AM, Jaegeuk Kim wrote:
> 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 <[email protected]>
> ---
> fs/f2fs/super.c | 590 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 590 insertions(+)
> create mode 100644 fs/f2fs/super.c
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> new file mode 100644
> index 0000000..8e608a0
> --- /dev/null
> +++ b/fs/f2fs/super.c
> @@ -0,0 +1,590 @@
> +/**
> + * 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/f2fs_fs.h>
> +
> +#include "f2fs.h"
> +#include "node.h"
> +#include "xattr.h"
> +
> +static struct kmem_cache *f2fs_inode_cachep;
> +static struct proc_dir_entry *f2fs_proc_root;
> +
> +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->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);
> +
> +#ifdef CONFIG_F2FS_STAT_FS
> + if (sbi->s_proc) {
> + f2fs_stat_exit(sbi);
> + remove_proc_entry(sb->s_id, f2fs_proc_root);
> + }
> +#endif
> + stop_gc_thread(sbi);
> +
> + write_checkpoint(sbi, false, true);
> +
> + iput(sbi->node_inode);
> + iput(sbi->meta_inode);
> +
> + /* destroy f2fs internal modules */
> + destroy_gc_manager(sbi);
> + 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);
> + 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 = sbi->gc_info->overp_segment_count
> + << 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;
> +
> + 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 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;
> +
> + result += (leaf_count * 2);
> +
> + leaf_count *= NIDS_PER_BLOCK;
> + result += (leaf_count * 2);
> +
> + leaf_count *= NIDS_PER_BLOCK;
> + result += (leaf_count * 2);
> +
> + result <<= bits;
> + return result;
> +}
I think that it needs to comment logic of max_file_size() function. It is not
so clear why it needs to multiply leaf_count on 2.
> +
> +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) != 9)
I think it makes sense to have special declaration for hardcoded 9.
> + return 1;
> + if (le32_to_cpu(raw_super->log_sectors_per_block) != 3)
I think it makes sense to have special declaration for hardcoded 3.
> + 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_sectorsize = le32_to_cpu(raw_super->log_sectorsize);
> + 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;
> + 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, F2FS_SUPER_OFFSET);
> + if (!raw_super_buf)
> + goto free_sbi;
> + raw_super = (struct f2fs_super_block *) ((char *)raw_super_buf->b_data);
> +
> + /* 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;
> +
> + sb->s_op = &f2fs_sops;
> + sb->s_xattr = f2fs_xattr_handlers;
> + sb->s_magic = F2FS_SUPER_MAGIC;
> + sb->s_fs_info = sbi;
> + sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
> + (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
> +
> + /* 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))
> + goto free_sb_buf;
> +
> + if (get_valid_checkpoint(sbi))
> + goto free_meta_inode;
> +
> + /* sanity checking of checkpoint */
> + 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 */
> + if (build_segment_manager(sbi))
> + goto free_sm;
> + if (build_node_manager(sbi))
> + goto free_nm;
> + if (build_gc_manager(sbi))
> + goto free_gc;
> +
> + /* get an inode for node space */
> + sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
> + if (IS_ERR(sbi->node_inode))
> + goto free_gc;
> +
> + /* if there are nt orphan nodes free them */
> + if (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))
> + 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)
> + goto free_root_inode;
> +
> + /* recover fsynced data */
> + if (!test_opt(sbi, DISABLE_ROLL_FORWARD))
> + recover_fsync_data(sbi);
> +
> + /* After POR, we can run background GC thread */
> + if (start_gc_thread(sbi))
> + goto fail;
> +
> +#ifdef CONFIG_F2FS_STAT_FS
> + if (f2fs_proc_root) {
> + sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
> + if (f2fs_stat_init(sbi))
> + goto fail;
> + }
> +#endif
> + return 0;
> +fail:
> + stop_gc_thread(sbi);
> +free_root_inode:
> + make_bad_inode(root);
> + iput(root);
> +free_node_inode:
> + make_bad_inode(sbi->node_inode);
> + iput(sbi->node_inode);
> +free_gc:
> + destroy_gc_manager(sbi);
> +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 -EINVAL;
The reason of failing in fill_super() can be different but this function report
-EINVAL always, as I understand. I think that it is not fully correct way of
reporting about failing.
> +}
> +
> +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)
> +{
> + if (init_inodecache())
> + goto fail;
> + if (create_node_manager_caches())
> + goto fail;
> + if (create_gc_caches())
> + goto fail;
> + if (create_checkpoint_caches())
> + goto fail;
> + if (register_filesystem(&f2fs_fs_type))
> + return -EBUSY;
Why EBUSY? Usually, it returns error code from register_filesystem().
> +
> + f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
> + return 0;
> +fail:
> + return -ENOMEM;
> +}
> +
> +static void __exit exit_f2fs_fs(void)
> +{
> + remove_proc_entry("fs/f2fs", NULL);
> + 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");
> --
> 1.7.9.5
>
>
>
>
> ---
> Jaegeuk Kim
> Samsung
>
>
>
> --
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With the best regards,
Vyacheslav Dubeyko.
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