diff options
Diffstat (limited to 'fs/jffs2/super.c')
-rw-r--r-- | fs/jffs2/super.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c new file mode 100644 index 00000000..853b8e30 --- /dev/null +++ b/fs/jffs2/super.c @@ -0,0 +1,316 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2001-2007 Red Hat, Inc. + * + * Created by David Woodhouse <dwmw2@infradead.org> + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/fs.h> +#include <linux/err.h> +#include <linux/mount.h> +#include <linux/jffs2.h> +#include <linux/pagemap.h> +#include <linux/mtd/super.h> +#include <linux/ctype.h> +#include <linux/namei.h> +#include <linux/exportfs.h> +#include "compr.h" +#include "nodelist.h" + +static void jffs2_put_super(struct super_block *); + +static struct kmem_cache *jffs2_inode_cachep; + +static struct inode *jffs2_alloc_inode(struct super_block *sb) +{ + struct jffs2_inode_info *f; + + f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); + if (!f) + return NULL; + return &f->vfs_inode; +} + +static void jffs2_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); +} + +static void jffs2_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, jffs2_i_callback); +} + +static void jffs2_i_init_once(void *foo) +{ + struct jffs2_inode_info *f = foo; + + mutex_init(&f->sem); + inode_init_once(&f->vfs_inode); +} + +static void jffs2_write_super(struct super_block *sb) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); + + lock_super(sb); + sb->s_dirt = 0; + + if (!(sb->s_flags & MS_RDONLY)) { + D1(printk(KERN_DEBUG "jffs2_write_super()\n")); + jffs2_flush_wbuf_gc(c, 0); + } + + unlock_super(sb); +} + +static int jffs2_sync_fs(struct super_block *sb, int wait) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); + + jffs2_write_super(sb); + + mutex_lock(&c->alloc_sem); + jffs2_flush_wbuf_pad(c); + mutex_unlock(&c->alloc_sem); + return 0; +} + +static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, + uint32_t generation) +{ + /* We don't care about i_generation. We'll destroy the flash + before we start re-using inode numbers anyway. And even + if that wasn't true, we'd have other problems...*/ + return jffs2_iget(sb, ino); +} + +static struct dentry *jffs2_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, + jffs2_nfs_get_inode); +} + +static struct dentry *jffs2_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, + jffs2_nfs_get_inode); +} + +static struct dentry *jffs2_get_parent(struct dentry *child) +{ + struct jffs2_inode_info *f; + uint32_t pino; + + BUG_ON(!S_ISDIR(child->d_inode->i_mode)); + + f = JFFS2_INODE_INFO(child->d_inode); + + pino = f->inocache->pino_nlink; + + JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", + f->inocache->ino, pino); + + return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); +} + +static const struct export_operations jffs2_export_ops = { + .get_parent = jffs2_get_parent, + .fh_to_dentry = jffs2_fh_to_dentry, + .fh_to_parent = jffs2_fh_to_parent, +}; + +static const struct super_operations jffs2_super_operations = +{ + .alloc_inode = jffs2_alloc_inode, + .destroy_inode =jffs2_destroy_inode, + .put_super = jffs2_put_super, + .write_super = jffs2_write_super, + .statfs = jffs2_statfs, + .remount_fs = jffs2_remount_fs, + .evict_inode = jffs2_evict_inode, + .dirty_inode = jffs2_dirty_inode, + .sync_fs = jffs2_sync_fs, +}; + +/* + * fill in the superblock + */ +static int jffs2_fill_super(struct super_block *sb, void *data, int silent) +{ + struct jffs2_sb_info *c; + int ret; + + D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" + " New superblock for device %d (\"%s\")\n", + sb->s_mtd->index, sb->s_mtd->name)); + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + c->mtd = sb->s_mtd; + c->os_priv = sb; + sb->s_fs_info = c; + + /* Initialize JFFS2 superblock locks, the further initialization will + * be done later */ + mutex_init(&c->alloc_sem); + mutex_init(&c->erase_free_sem); + init_waitqueue_head(&c->erase_wait); + init_waitqueue_head(&c->inocache_wq); + spin_lock_init(&c->erase_completion_lock); + spin_lock_init(&c->inocache_lock); + + sb->s_op = &jffs2_super_operations; + sb->s_export_op = &jffs2_export_ops; + sb->s_flags = sb->s_flags | MS_NOATIME; + sb->s_xattr = jffs2_xattr_handlers; +#ifdef CONFIG_JFFS2_FS_POSIX_ACL + sb->s_flags |= MS_POSIXACL; +#endif + ret = jffs2_do_fill_super(sb, data, silent); + return ret; +} + +static struct dentry *jffs2_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *data) +{ + return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super); +} + +static void jffs2_put_super (struct super_block *sb) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); + + D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); + + if (sb->s_dirt) + jffs2_write_super(sb); + + mutex_lock(&c->alloc_sem); + jffs2_flush_wbuf_pad(c); + mutex_unlock(&c->alloc_sem); + + jffs2_sum_exit(c); + + jffs2_free_ino_caches(c); + jffs2_free_raw_node_refs(c); + if (jffs2_blocks_use_vmalloc(c)) + vfree(c->blocks); + else + kfree(c->blocks); + jffs2_flash_cleanup(c); + kfree(c->inocache_list); + jffs2_clear_xattr_subsystem(c); + if (c->mtd->sync) + c->mtd->sync(c->mtd); + + D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); +} + +static void jffs2_kill_sb(struct super_block *sb) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); + if (!(sb->s_flags & MS_RDONLY)) + jffs2_stop_garbage_collect_thread(c); + kill_mtd_super(sb); + kfree(c); +} + +static struct file_system_type jffs2_fs_type = { + .owner = THIS_MODULE, + .name = "jffs2", + .mount = jffs2_mount, + .kill_sb = jffs2_kill_sb, +}; + +static int __init init_jffs2_fs(void) +{ + int ret; + + /* Paranoia checks for on-medium structures. If we ask GCC + to pack them with __attribute__((packed)) then it _also_ + assumes that they're not aligned -- so it emits crappy + code on some architectures. Ideally we want an attribute + which means just 'no padding', without the alignment + thing. But GCC doesn't have that -- we have to just + hope the structs are the right sizes, instead. */ + BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); + BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); + BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); + BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); + + printk(KERN_INFO "JFFS2 version 2.2." +#ifdef CONFIG_JFFS2_FS_WRITEBUFFER + " (NAND)" +#endif +#ifdef CONFIG_JFFS2_SUMMARY + " (SUMMARY) " +#endif + " © 2001-2006 Red Hat, Inc.\n"); + + jffs2_inode_cachep = kmem_cache_create("jffs2_i", + sizeof(struct jffs2_inode_info), + 0, (SLAB_RECLAIM_ACCOUNT| + SLAB_MEM_SPREAD), + jffs2_i_init_once); + if (!jffs2_inode_cachep) { + printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); + return -ENOMEM; + } + ret = jffs2_compressors_init(); + if (ret) { + printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); + goto out; + } + ret = jffs2_create_slab_caches(); + if (ret) { + printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); + goto out_compressors; + } + ret = register_filesystem(&jffs2_fs_type); + if (ret) { + printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); + goto out_slab; + } + return 0; + + out_slab: + jffs2_destroy_slab_caches(); + out_compressors: + jffs2_compressors_exit(); + out: + kmem_cache_destroy(jffs2_inode_cachep); + return ret; +} + +static void __exit exit_jffs2_fs(void) +{ + unregister_filesystem(&jffs2_fs_type); + jffs2_destroy_slab_caches(); + jffs2_compressors_exit(); + kmem_cache_destroy(jffs2_inode_cachep); +} + +module_init(init_jffs2_fs); +module_exit(exit_jffs2_fs); + +MODULE_DESCRIPTION("The Journalling Flash File System, v2"); +MODULE_AUTHOR("Red Hat, Inc."); +MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for + // the sake of this tag. It's Free Software. |