diff options
Diffstat (limited to 'fs/jffs2/super.c')
-rw-r--r-- | fs/jffs2/super.c | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c new file mode 100644 index 000000000000..6b2a441d2766 --- /dev/null +++ b/fs/jffs2/super.c @@ -0,0 +1,365 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright (C) 2001-2003 Red Hat, Inc. + * + * Created by David Woodhouse <dwmw2@infradead.org> + * + * For licensing information, see the file 'LICENCE' in this directory. + * + * $Id: super.c,v 1.104 2004/11/23 15:37:31 gleixner Exp $ + * + */ + +#include <linux/config.h> +#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/mount.h> +#include <linux/jffs2.h> +#include <linux/pagemap.h> +#include <linux/mtd/mtd.h> +#include <linux/ctype.h> +#include <linux/namei.h> +#include "compr.h" +#include "nodelist.h" + +static void jffs2_put_super(struct super_block *); + +static kmem_cache_t *jffs2_inode_cachep; + +static struct inode *jffs2_alloc_inode(struct super_block *sb) +{ + struct jffs2_inode_info *ei; + ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, SLAB_KERNEL); + if (!ei) + return NULL; + return &ei->vfs_inode; +} + +static void jffs2_destroy_inode(struct inode *inode) +{ + kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); +} + +static void jffs2_i_init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) +{ + struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo; + + if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == + SLAB_CTOR_CONSTRUCTOR) { + init_MUTEX_LOCKED(&ei->sem); + inode_init_once(&ei->vfs_inode); + } +} + +static int jffs2_sync_fs(struct super_block *sb, int wait) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); + + down(&c->alloc_sem); + jffs2_flush_wbuf_pad(c); + up(&c->alloc_sem); + return 0; +} + +static struct super_operations jffs2_super_operations = +{ + .alloc_inode = jffs2_alloc_inode, + .destroy_inode =jffs2_destroy_inode, + .read_inode = jffs2_read_inode, + .put_super = jffs2_put_super, + .write_super = jffs2_write_super, + .statfs = jffs2_statfs, + .remount_fs = jffs2_remount_fs, + .clear_inode = jffs2_clear_inode, + .dirty_inode = jffs2_dirty_inode, + .sync_fs = jffs2_sync_fs, +}; + +static int jffs2_sb_compare(struct super_block *sb, void *data) +{ + struct jffs2_sb_info *p = data; + struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); + + /* The superblocks are considered to be equivalent if the underlying MTD + device is the same one */ + if (c->mtd == p->mtd) { + D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name)); + return 1; + } else { + D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n", + c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name)); + return 0; + } +} + +static int jffs2_sb_set(struct super_block *sb, void *data) +{ + struct jffs2_sb_info *p = data; + + /* For persistence of NFS exports etc. we use the same s_dev + each time we mount the device, don't just use an anonymous + device */ + sb->s_fs_info = p; + p->os_priv = sb; + sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index); + + return 0; +} + +static struct super_block *jffs2_get_sb_mtd(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *data, struct mtd_info *mtd) +{ + struct super_block *sb; + struct jffs2_sb_info *c; + int ret; + + c = kmalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return ERR_PTR(-ENOMEM); + memset(c, 0, sizeof(*c)); + c->mtd = mtd; + + sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c); + + if (IS_ERR(sb)) + goto out_put; + + if (sb->s_root) { + /* New mountpoint for JFFS2 which is already mounted */ + D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n", + mtd->index, mtd->name)); + goto out_put; + } + + D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n", + mtd->index, mtd->name)); + + sb->s_op = &jffs2_super_operations; + sb->s_flags = flags | MS_NOATIME; + + ret = jffs2_do_fill_super(sb, data, (flags&MS_VERBOSE)?1:0); + + if (ret) { + /* Failure case... */ + up_write(&sb->s_umount); + deactivate_super(sb); + return ERR_PTR(ret); + } + + sb->s_flags |= MS_ACTIVE; + return sb; + + out_put: + kfree(c); + put_mtd_device(mtd); + + return sb; +} + +static struct super_block *jffs2_get_sb_mtdnr(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *data, int mtdnr) +{ + struct mtd_info *mtd; + + mtd = get_mtd_device(NULL, mtdnr); + if (!mtd) { + D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); + return ERR_PTR(-EINVAL); + } + + return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd); +} + +static struct super_block *jffs2_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *data) +{ + int err; + struct nameidata nd; + int mtdnr; + + if (!dev_name) + return ERR_PTR(-EINVAL); + + D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); + + /* The preferred way of mounting in future; especially when + CONFIG_BLK_DEV is implemented - we specify the underlying + MTD device by number or by name, so that we don't require + block device support to be present in the kernel. */ + + /* FIXME: How to do the root fs this way? */ + + if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { + /* Probably mounting without the blkdev crap */ + if (dev_name[3] == ':') { + struct mtd_info *mtd; + + /* Mount by MTD device name */ + D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); + for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { + mtd = get_mtd_device(NULL, mtdnr); + if (mtd) { + if (!strcmp(mtd->name, dev_name+4)) + return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd); + put_mtd_device(mtd); + } + } + printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); + } else if (isdigit(dev_name[3])) { + /* Mount by MTD device number name */ + char *endptr; + + mtdnr = simple_strtoul(dev_name+3, &endptr, 0); + if (!*endptr) { + /* It was a valid number */ + D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); + return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr); + } + } + } + + /* Try the old way - the hack where we allowed users to mount + /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ + + err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); + + D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", + err, nd.dentry->d_inode)); + + if (err) + return ERR_PTR(err); + + err = -EINVAL; + + if (!S_ISBLK(nd.dentry->d_inode->i_mode)) + goto out; + + if (nd.mnt->mnt_flags & MNT_NODEV) { + err = -EACCES; + goto out; + } + + if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { + if (!(flags & MS_VERBOSE)) /* Yes I mean this. Strangely */ + printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", + dev_name); + goto out; + } + + mtdnr = iminor(nd.dentry->d_inode); + path_release(&nd); + + return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr); + +out: + path_release(&nd); + return ERR_PTR(err); +} + +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_flags & MS_RDONLY)) + jffs2_stop_garbage_collect_thread(c); + down(&c->alloc_sem); + jffs2_flush_wbuf_pad(c); + up(&c->alloc_sem); + jffs2_free_ino_caches(c); + jffs2_free_raw_node_refs(c); + if (c->mtd->flags & MTD_NO_VIRTBLOCKS) + vfree(c->blocks); + else + kfree(c->blocks); + jffs2_flash_cleanup(c); + kfree(c->inocache_list); + 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); + generic_shutdown_super(sb); + put_mtd_device(c->mtd); + kfree(c); +} + +static struct file_system_type jffs2_fs_type = { + .owner = THIS_MODULE, + .name = "jffs2", + .get_sb = jffs2_get_sb, + .kill_sb = jffs2_kill_sb, +}; + +static int __init init_jffs2_fs(void) +{ + int ret; + + printk(KERN_INFO "JFFS2 version 2.2." +#ifdef CONFIG_JFFS2_FS_NAND + " (NAND)" +#endif + " (C) 2001-2003 Red Hat, Inc.\n"); + + jffs2_inode_cachep = kmem_cache_create("jffs2_i", + sizeof(struct jffs2_inode_info), + 0, SLAB_RECLAIM_ACCOUNT, + jffs2_i_init_once, NULL); + 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. |