![Christoph Lameter](/assets/img/avatar_default.png)
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by SLAB. I think its purpose was to have a callback after an object has been freed to verify that the state is the constructor state again? The callback is performed before each freeing of an object. I would think that it is much easier to check the object state manually before the free. That also places the check near the code object manipulation of the object. Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was compiled with SLAB debugging on. If there would be code in a constructor handling SLAB_DEBUG_INITIAL then it would have to be conditional on SLAB_DEBUG otherwise it would just be dead code. But there is no such code in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real use of, difficult to understand and there are easier ways to accomplish the same effect (i.e. add debug code before kfree). There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be clear in fs inode caches. Remove the pointless checks (they would even be pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors. This is the last slab flag that SLUB did not support. Remove the check for unimplemented flags from SLUB. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
399 lines
10 KiB
C
399 lines
10 KiB
C
/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright © 2001-2007 Red Hat, Inc.
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*
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* Created by David Woodhouse <dwmw2@infradead.org>
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/fs.h>
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#include <linux/err.h>
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#include <linux/mount.h>
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#include <linux/jffs2.h>
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#include <linux/pagemap.h>
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#include <linux/mtd/mtd.h>
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#include <linux/ctype.h>
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#include <linux/namei.h>
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#include "compr.h"
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#include "nodelist.h"
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static void jffs2_put_super(struct super_block *);
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static struct kmem_cache *jffs2_inode_cachep;
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static struct inode *jffs2_alloc_inode(struct super_block *sb)
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{
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struct jffs2_inode_info *ei;
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ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
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if (!ei)
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return NULL;
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return &ei->vfs_inode;
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}
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static void jffs2_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
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}
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static void jffs2_i_init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
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{
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struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo;
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if (flags & SLAB_CTOR_CONSTRUCTOR) {
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init_MUTEX(&ei->sem);
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inode_init_once(&ei->vfs_inode);
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}
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}
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static int jffs2_sync_fs(struct super_block *sb, int wait)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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down(&c->alloc_sem);
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jffs2_flush_wbuf_pad(c);
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up(&c->alloc_sem);
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return 0;
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}
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static const struct super_operations jffs2_super_operations =
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{
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.alloc_inode = jffs2_alloc_inode,
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.destroy_inode =jffs2_destroy_inode,
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.read_inode = jffs2_read_inode,
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.put_super = jffs2_put_super,
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.write_super = jffs2_write_super,
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.statfs = jffs2_statfs,
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.remount_fs = jffs2_remount_fs,
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.clear_inode = jffs2_clear_inode,
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.dirty_inode = jffs2_dirty_inode,
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.sync_fs = jffs2_sync_fs,
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};
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static int jffs2_sb_compare(struct super_block *sb, void *data)
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{
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struct jffs2_sb_info *p = data;
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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/* The superblocks are considered to be equivalent if the underlying MTD
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device is the same one */
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if (c->mtd == p->mtd) {
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D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name));
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return 1;
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} else {
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D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n",
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c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name));
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return 0;
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}
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}
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static int jffs2_sb_set(struct super_block *sb, void *data)
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{
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struct jffs2_sb_info *p = data;
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/* For persistence of NFS exports etc. we use the same s_dev
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each time we mount the device, don't just use an anonymous
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device */
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sb->s_fs_info = p;
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p->os_priv = sb;
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sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index);
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return 0;
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}
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static int jffs2_get_sb_mtd(struct file_system_type *fs_type,
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int flags, const char *dev_name,
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void *data, struct mtd_info *mtd,
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struct vfsmount *mnt)
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{
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struct super_block *sb;
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struct jffs2_sb_info *c;
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int ret;
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c = kzalloc(sizeof(*c), GFP_KERNEL);
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if (!c)
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return -ENOMEM;
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c->mtd = mtd;
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sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c);
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if (IS_ERR(sb))
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goto out_error;
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if (sb->s_root) {
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/* New mountpoint for JFFS2 which is already mounted */
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D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n",
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mtd->index, mtd->name));
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ret = simple_set_mnt(mnt, sb);
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goto out_put;
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}
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D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n",
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mtd->index, mtd->name));
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/* Initialize JFFS2 superblock locks, the further initialization will be
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* done later */
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init_MUTEX(&c->alloc_sem);
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init_MUTEX(&c->erase_free_sem);
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init_waitqueue_head(&c->erase_wait);
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init_waitqueue_head(&c->inocache_wq);
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spin_lock_init(&c->erase_completion_lock);
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spin_lock_init(&c->inocache_lock);
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sb->s_op = &jffs2_super_operations;
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sb->s_flags = flags | MS_NOATIME;
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sb->s_xattr = jffs2_xattr_handlers;
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#ifdef CONFIG_JFFS2_FS_POSIX_ACL
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sb->s_flags |= MS_POSIXACL;
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#endif
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ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
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if (ret) {
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/* Failure case... */
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up_write(&sb->s_umount);
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deactivate_super(sb);
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return ret;
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}
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sb->s_flags |= MS_ACTIVE;
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return simple_set_mnt(mnt, sb);
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out_error:
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ret = PTR_ERR(sb);
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out_put:
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kfree(c);
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put_mtd_device(mtd);
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return ret;
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}
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static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type,
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int flags, const char *dev_name,
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void *data, int mtdnr,
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struct vfsmount *mnt)
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{
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struct mtd_info *mtd;
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mtd = get_mtd_device(NULL, mtdnr);
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if (IS_ERR(mtd)) {
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D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr));
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return PTR_ERR(mtd);
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}
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return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt);
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}
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static int jffs2_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name,
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void *data, struct vfsmount *mnt)
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{
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int err;
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struct nameidata nd;
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int mtdnr;
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if (!dev_name)
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return -EINVAL;
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D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name));
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/* The preferred way of mounting in future; especially when
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CONFIG_BLK_DEV is implemented - we specify the underlying
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MTD device by number or by name, so that we don't require
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block device support to be present in the kernel. */
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/* FIXME: How to do the root fs this way? */
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if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
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/* Probably mounting without the blkdev crap */
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if (dev_name[3] == ':') {
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struct mtd_info *mtd;
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/* Mount by MTD device name */
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D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4));
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for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
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mtd = get_mtd_device(NULL, mtdnr);
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if (!IS_ERR(mtd)) {
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if (!strcmp(mtd->name, dev_name+4))
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return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt);
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put_mtd_device(mtd);
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}
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}
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printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4);
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} else if (isdigit(dev_name[3])) {
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/* Mount by MTD device number name */
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char *endptr;
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mtdnr = simple_strtoul(dev_name+3, &endptr, 0);
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if (!*endptr) {
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/* It was a valid number */
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D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr));
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return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt);
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}
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}
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}
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/* Try the old way - the hack where we allowed users to mount
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/dev/mtdblock$(n) but didn't actually _use_ the blkdev */
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err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
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D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n",
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err, nd.dentry->d_inode));
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if (err)
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return err;
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err = -EINVAL;
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if (!S_ISBLK(nd.dentry->d_inode->i_mode))
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goto out;
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if (nd.mnt->mnt_flags & MNT_NODEV) {
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err = -EACCES;
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goto out;
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}
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if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) {
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if (!(flags & MS_SILENT))
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printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n",
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dev_name);
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goto out;
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}
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mtdnr = iminor(nd.dentry->d_inode);
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path_release(&nd);
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return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt);
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out:
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path_release(&nd);
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return err;
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}
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static void jffs2_put_super (struct super_block *sb)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
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down(&c->alloc_sem);
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jffs2_flush_wbuf_pad(c);
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up(&c->alloc_sem);
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jffs2_sum_exit(c);
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jffs2_free_ino_caches(c);
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jffs2_free_raw_node_refs(c);
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if (jffs2_blocks_use_vmalloc(c))
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vfree(c->blocks);
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else
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kfree(c->blocks);
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jffs2_flash_cleanup(c);
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kfree(c->inocache_list);
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jffs2_clear_xattr_subsystem(c);
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if (c->mtd->sync)
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c->mtd->sync(c->mtd);
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D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
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}
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static void jffs2_kill_sb(struct super_block *sb)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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if (!(sb->s_flags & MS_RDONLY))
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jffs2_stop_garbage_collect_thread(c);
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generic_shutdown_super(sb);
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put_mtd_device(c->mtd);
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kfree(c);
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}
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static struct file_system_type jffs2_fs_type = {
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.owner = THIS_MODULE,
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.name = "jffs2",
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.get_sb = jffs2_get_sb,
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.kill_sb = jffs2_kill_sb,
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};
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static int __init init_jffs2_fs(void)
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{
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int ret;
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/* Paranoia checks for on-medium structures. If we ask GCC
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to pack them with __attribute__((packed)) then it _also_
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assumes that they're not aligned -- so it emits crappy
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code on some architectures. Ideally we want an attribute
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which means just 'no padding', without the alignment
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thing. But GCC doesn't have that -- we have to just
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hope the structs are the right sizes, instead. */
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BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
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BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
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BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
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BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
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printk(KERN_INFO "JFFS2 version 2.2."
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#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
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" (NAND)"
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#endif
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#ifdef CONFIG_JFFS2_SUMMARY
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" (SUMMARY) "
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#endif
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" © 2001-2006 Red Hat, Inc.\n");
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jffs2_inode_cachep = kmem_cache_create("jffs2_i",
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sizeof(struct jffs2_inode_info),
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0, (SLAB_RECLAIM_ACCOUNT|
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SLAB_MEM_SPREAD),
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jffs2_i_init_once, NULL);
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if (!jffs2_inode_cachep) {
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printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
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return -ENOMEM;
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}
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ret = jffs2_compressors_init();
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if (ret) {
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printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
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goto out;
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}
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ret = jffs2_create_slab_caches();
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if (ret) {
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printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
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goto out_compressors;
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}
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ret = register_filesystem(&jffs2_fs_type);
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if (ret) {
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printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
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goto out_slab;
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}
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return 0;
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out_slab:
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jffs2_destroy_slab_caches();
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out_compressors:
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jffs2_compressors_exit();
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out:
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kmem_cache_destroy(jffs2_inode_cachep);
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return ret;
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}
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static void __exit exit_jffs2_fs(void)
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{
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unregister_filesystem(&jffs2_fs_type);
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jffs2_destroy_slab_caches();
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jffs2_compressors_exit();
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kmem_cache_destroy(jffs2_inode_cachep);
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}
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module_init(init_jffs2_fs);
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module_exit(exit_jffs2_fs);
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MODULE_DESCRIPTION("The Journalling Flash File System, v2");
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MODULE_AUTHOR("Red Hat, Inc.");
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MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
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// the sake of this tag. It's Free Software.
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