linux/fs/jffs2/fs.c
Baokun Li 4c7c44ee16 jffs2: fix use-after-free in jffs2_clear_xattr_subsystem
When we mount a jffs2 image, assume that the first few blocks of
the image are normal and contain at least one xattr-related inode,
but the next block is abnormal. As a result, an error is returned
in jffs2_scan_eraseblock(). jffs2_clear_xattr_subsystem() is then
called in jffs2_build_filesystem() and then again in
jffs2_do_fill_super().

Finally we can observe the following report:
 ==================================================================
 BUG: KASAN: use-after-free in jffs2_clear_xattr_subsystem+0x95/0x6ac
 Read of size 8 at addr ffff8881243384e0 by task mount/719

 Call Trace:
  dump_stack+0x115/0x16b
  jffs2_clear_xattr_subsystem+0x95/0x6ac
  jffs2_do_fill_super+0x84f/0xc30
  jffs2_fill_super+0x2ea/0x4c0
  mtd_get_sb+0x254/0x400
  mtd_get_sb_by_nr+0x4f/0xd0
  get_tree_mtd+0x498/0x840
  jffs2_get_tree+0x25/0x30
  vfs_get_tree+0x8d/0x2e0
  path_mount+0x50f/0x1e50
  do_mount+0x107/0x130
  __se_sys_mount+0x1c5/0x2f0
  __x64_sys_mount+0xc7/0x160
  do_syscall_64+0x45/0x70
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

 Allocated by task 719:
  kasan_save_stack+0x23/0x60
  __kasan_kmalloc.constprop.0+0x10b/0x120
  kasan_slab_alloc+0x12/0x20
  kmem_cache_alloc+0x1c0/0x870
  jffs2_alloc_xattr_ref+0x2f/0xa0
  jffs2_scan_medium.cold+0x3713/0x4794
  jffs2_do_mount_fs.cold+0xa7/0x2253
  jffs2_do_fill_super+0x383/0xc30
  jffs2_fill_super+0x2ea/0x4c0
 [...]

 Freed by task 719:
  kmem_cache_free+0xcc/0x7b0
  jffs2_free_xattr_ref+0x78/0x98
  jffs2_clear_xattr_subsystem+0xa1/0x6ac
  jffs2_do_mount_fs.cold+0x5e6/0x2253
  jffs2_do_fill_super+0x383/0xc30
  jffs2_fill_super+0x2ea/0x4c0
 [...]

 The buggy address belongs to the object at ffff8881243384b8
  which belongs to the cache jffs2_xattr_ref of size 48
 The buggy address is located 40 bytes inside of
  48-byte region [ffff8881243384b8, ffff8881243384e8)
 [...]
 ==================================================================

The triggering of the BUG is shown in the following stack:
-----------------------------------------------------------
jffs2_fill_super
  jffs2_do_fill_super
    jffs2_do_mount_fs
      jffs2_build_filesystem
        jffs2_scan_medium
          jffs2_scan_eraseblock        <--- ERROR
        jffs2_clear_xattr_subsystem    <--- free
    jffs2_clear_xattr_subsystem        <--- free again
-----------------------------------------------------------

An error is returned in jffs2_do_mount_fs(). If the error is returned
by jffs2_sum_init(), the jffs2_clear_xattr_subsystem() does not need to
be executed. If the error is returned by jffs2_build_filesystem(), the
jffs2_clear_xattr_subsystem() also does not need to be executed again.
So move jffs2_clear_xattr_subsystem() from 'out_inohash' to 'out_root'
to fix this UAF problem.

Fixes: aa98d7cf59 ("[JFFS2][XATTR] XATTR support on JFFS2 (version. 5)")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-03-16 22:52:27 +01:00

741 lines
19 KiB
C

/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright © 2001-2007 Red Hat, Inc.
* Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
*
* Created by David Woodhouse <dwmw2@infradead.org>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/list.h>
#include <linux/mtd/mtd.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/vfs.h>
#include <linux/crc32.h>
#include "nodelist.h"
static int jffs2_flash_setup(struct jffs2_sb_info *c);
int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
{
struct jffs2_full_dnode *old_metadata, *new_metadata;
struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
struct jffs2_raw_inode *ri;
union jffs2_device_node dev;
unsigned char *mdata = NULL;
int mdatalen = 0;
unsigned int ivalid;
uint32_t alloclen;
int ret;
int alloc_type = ALLOC_NORMAL;
jffs2_dbg(1, "%s(): ino #%lu\n", __func__, inode->i_ino);
/* Special cases - we don't want more than one data node
for these types on the medium at any time. So setattr
must read the original data associated with the node
(i.e. the device numbers or the target name) and write
it out again with the appropriate data attached */
if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
/* For these, we don't actually need to read the old node */
mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
mdata = (char *)&dev;
jffs2_dbg(1, "%s(): Writing %d bytes of kdev_t\n",
__func__, mdatalen);
} else if (S_ISLNK(inode->i_mode)) {
mutex_lock(&f->sem);
mdatalen = f->metadata->size;
mdata = kmalloc(f->metadata->size, GFP_USER);
if (!mdata) {
mutex_unlock(&f->sem);
return -ENOMEM;
}
ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
if (ret) {
mutex_unlock(&f->sem);
kfree(mdata);
return ret;
}
mutex_unlock(&f->sem);
jffs2_dbg(1, "%s(): Writing %d bytes of symlink target\n",
__func__, mdatalen);
}
ri = jffs2_alloc_raw_inode();
if (!ri) {
if (S_ISLNK(inode->i_mode))
kfree(mdata);
return -ENOMEM;
}
ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
if (ret) {
jffs2_free_raw_inode(ri);
if (S_ISLNK(inode->i_mode))
kfree(mdata);
return ret;
}
mutex_lock(&f->sem);
ivalid = iattr->ia_valid;
ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
ri->ino = cpu_to_je32(inode->i_ino);
ri->version = cpu_to_je32(++f->highest_version);
ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));
if (ivalid & ATTR_MODE)
ri->mode = cpu_to_jemode(iattr->ia_mode);
else
ri->mode = cpu_to_jemode(inode->i_mode);
ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime));
ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime));
ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime));
ri->offset = cpu_to_je32(0);
ri->csize = ri->dsize = cpu_to_je32(mdatalen);
ri->compr = JFFS2_COMPR_NONE;
if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
/* It's an extension. Make it a hole node */
ri->compr = JFFS2_COMPR_ZERO;
ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
ri->offset = cpu_to_je32(inode->i_size);
} else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
/* For truncate-to-zero, treat it as deletion because
it'll always be obsoleting all previous nodes */
alloc_type = ALLOC_DELETION;
}
ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
if (mdatalen)
ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
else
ri->data_crc = cpu_to_je32(0);
new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
if (S_ISLNK(inode->i_mode))
kfree(mdata);
if (IS_ERR(new_metadata)) {
jffs2_complete_reservation(c);
jffs2_free_raw_inode(ri);
mutex_unlock(&f->sem);
return PTR_ERR(new_metadata);
}
/* It worked. Update the inode */
inode->i_atime = ITIME(je32_to_cpu(ri->atime));
inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
inode->i_mode = jemode_to_cpu(ri->mode);
i_uid_write(inode, je16_to_cpu(ri->uid));
i_gid_write(inode, je16_to_cpu(ri->gid));
old_metadata = f->metadata;
if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);
if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
jffs2_add_full_dnode_to_inode(c, f, new_metadata);
inode->i_size = iattr->ia_size;
inode->i_blocks = (inode->i_size + 511) >> 9;
f->metadata = NULL;
} else {
f->metadata = new_metadata;
}
if (old_metadata) {
jffs2_mark_node_obsolete(c, old_metadata->raw);
jffs2_free_full_dnode(old_metadata);
}
jffs2_free_raw_inode(ri);
mutex_unlock(&f->sem);
jffs2_complete_reservation(c);
/* We have to do the truncate_setsize() without f->sem held, since
some pages may be locked and waiting for it in readpage().
We are protected from a simultaneous write() extending i_size
back past iattr->ia_size, because do_truncate() holds the
generic inode semaphore. */
if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
truncate_setsize(inode, iattr->ia_size);
inode->i_blocks = (inode->i_size + 511) >> 9;
}
return 0;
}
int jffs2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
int rc;
rc = setattr_prepare(&init_user_ns, dentry, iattr);
if (rc)
return rc;
rc = jffs2_do_setattr(inode, iattr);
if (!rc && (iattr->ia_valid & ATTR_MODE))
rc = posix_acl_chmod(&init_user_ns, inode, inode->i_mode);
return rc;
}
int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct jffs2_sb_info *c = JFFS2_SB_INFO(dentry->d_sb);
unsigned long avail;
buf->f_type = JFFS2_SUPER_MAGIC;
buf->f_bsize = 1 << PAGE_SHIFT;
buf->f_blocks = c->flash_size >> PAGE_SHIFT;
buf->f_files = 0;
buf->f_ffree = 0;
buf->f_namelen = JFFS2_MAX_NAME_LEN;
buf->f_fsid.val[0] = JFFS2_SUPER_MAGIC;
buf->f_fsid.val[1] = c->mtd->index;
spin_lock(&c->erase_completion_lock);
avail = c->dirty_size + c->free_size;
if (avail > c->sector_size * c->resv_blocks_write)
avail -= c->sector_size * c->resv_blocks_write;
else
avail = 0;
spin_unlock(&c->erase_completion_lock);
buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
return 0;
}
void jffs2_evict_inode (struct inode *inode)
{
/* We can forget about this inode for now - drop all
* the nodelists associated with it, etc.
*/
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
jffs2_dbg(1, "%s(): ino #%lu mode %o\n",
__func__, inode->i_ino, inode->i_mode);
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
jffs2_do_clear_inode(c, f);
}
struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
{
struct jffs2_inode_info *f;
struct jffs2_sb_info *c;
struct jffs2_raw_inode latest_node;
union jffs2_device_node jdev;
struct inode *inode;
dev_t rdev = 0;
int ret;
jffs2_dbg(1, "%s(): ino == %lu\n", __func__, ino);
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
f = JFFS2_INODE_INFO(inode);
c = JFFS2_SB_INFO(inode->i_sb);
jffs2_init_inode_info(f);
mutex_lock(&f->sem);
ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
if (ret)
goto error;
inode->i_mode = jemode_to_cpu(latest_node.mode);
i_uid_write(inode, je16_to_cpu(latest_node.uid));
i_gid_write(inode, je16_to_cpu(latest_node.gid));
inode->i_size = je32_to_cpu(latest_node.isize);
inode->i_atime = ITIME(je32_to_cpu(latest_node.atime));
inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime));
inode->i_ctime = ITIME(je32_to_cpu(latest_node.ctime));
set_nlink(inode, f->inocache->pino_nlink);
inode->i_blocks = (inode->i_size + 511) >> 9;
switch (inode->i_mode & S_IFMT) {
case S_IFLNK:
inode->i_op = &jffs2_symlink_inode_operations;
inode->i_link = f->target;
break;
case S_IFDIR:
{
struct jffs2_full_dirent *fd;
set_nlink(inode, 2); /* parent and '.' */
for (fd=f->dents; fd; fd = fd->next) {
if (fd->type == DT_DIR && fd->ino)
inc_nlink(inode);
}
/* Root dir gets i_nlink 3 for some reason */
if (inode->i_ino == 1)
inc_nlink(inode);
inode->i_op = &jffs2_dir_inode_operations;
inode->i_fop = &jffs2_dir_operations;
break;
}
case S_IFREG:
inode->i_op = &jffs2_file_inode_operations;
inode->i_fop = &jffs2_file_operations;
inode->i_mapping->a_ops = &jffs2_file_address_operations;
inode->i_mapping->nrpages = 0;
break;
case S_IFBLK:
case S_IFCHR:
/* Read the device numbers from the media */
if (f->metadata->size != sizeof(jdev.old_id) &&
f->metadata->size != sizeof(jdev.new_id)) {
pr_notice("Device node has strange size %d\n",
f->metadata->size);
goto error_io;
}
jffs2_dbg(1, "Reading device numbers from flash\n");
ret = jffs2_read_dnode(c, f, f->metadata, (char *)&jdev, 0, f->metadata->size);
if (ret < 0) {
/* Eep */
pr_notice("Read device numbers for inode %lu failed\n",
(unsigned long)inode->i_ino);
goto error;
}
if (f->metadata->size == sizeof(jdev.old_id))
rdev = old_decode_dev(je16_to_cpu(jdev.old_id));
else
rdev = new_decode_dev(je32_to_cpu(jdev.new_id));
fallthrough;
case S_IFSOCK:
case S_IFIFO:
inode->i_op = &jffs2_file_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
default:
pr_warn("%s(): Bogus i_mode %o for ino %lu\n",
__func__, inode->i_mode, (unsigned long)inode->i_ino);
}
mutex_unlock(&f->sem);
jffs2_dbg(1, "jffs2_read_inode() returning\n");
unlock_new_inode(inode);
return inode;
error_io:
ret = -EIO;
error:
mutex_unlock(&f->sem);
iget_failed(inode);
return ERR_PTR(ret);
}
void jffs2_dirty_inode(struct inode *inode, int flags)
{
struct iattr iattr;
if (!(inode->i_state & I_DIRTY_DATASYNC)) {
jffs2_dbg(2, "%s(): not calling setattr() for ino #%lu\n",
__func__, inode->i_ino);
return;
}
jffs2_dbg(1, "%s(): calling setattr() for ino #%lu\n",
__func__, inode->i_ino);
iattr.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_MTIME|ATTR_CTIME;
iattr.ia_mode = inode->i_mode;
iattr.ia_uid = inode->i_uid;
iattr.ia_gid = inode->i_gid;
iattr.ia_atime = inode->i_atime;
iattr.ia_mtime = inode->i_mtime;
iattr.ia_ctime = inode->i_ctime;
jffs2_do_setattr(inode, &iattr);
}
int jffs2_do_remount_fs(struct super_block *sb, struct fs_context *fc)
{
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
if (c->flags & JFFS2_SB_FLAG_RO && !sb_rdonly(sb))
return -EROFS;
/* We stop if it was running, then restart if it needs to.
This also catches the case where it was stopped and this
is just a remount to restart it.
Flush the writebuffer, if neccecary, else we loose it */
if (!sb_rdonly(sb)) {
jffs2_stop_garbage_collect_thread(c);
mutex_lock(&c->alloc_sem);
jffs2_flush_wbuf_pad(c);
mutex_unlock(&c->alloc_sem);
}
if (!(fc->sb_flags & SB_RDONLY))
jffs2_start_garbage_collect_thread(c);
fc->sb_flags |= SB_NOATIME;
return 0;
}
/* jffs2_new_inode: allocate a new inode and inocache, add it to the hash,
fill in the raw_inode while you're at it. */
struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_raw_inode *ri)
{
struct inode *inode;
struct super_block *sb = dir_i->i_sb;
struct jffs2_sb_info *c;
struct jffs2_inode_info *f;
int ret;
jffs2_dbg(1, "%s(): dir_i %ld, mode 0x%x\n",
__func__, dir_i->i_ino, mode);
c = JFFS2_SB_INFO(sb);
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
f = JFFS2_INODE_INFO(inode);
jffs2_init_inode_info(f);
mutex_lock(&f->sem);
memset(ri, 0, sizeof(*ri));
/* Set OS-specific defaults for new inodes */
ri->uid = cpu_to_je16(from_kuid(&init_user_ns, current_fsuid()));
if (dir_i->i_mode & S_ISGID) {
ri->gid = cpu_to_je16(i_gid_read(dir_i));
if (S_ISDIR(mode))
mode |= S_ISGID;
} else {
ri->gid = cpu_to_je16(from_kgid(&init_user_ns, current_fsgid()));
}
/* POSIX ACLs have to be processed now, at least partly.
The umask is only applied if there's no default ACL */
ret = jffs2_init_acl_pre(dir_i, inode, &mode);
if (ret) {
mutex_unlock(&f->sem);
make_bad_inode(inode);
iput(inode);
return ERR_PTR(ret);
}
ret = jffs2_do_new_inode (c, f, mode, ri);
if (ret) {
mutex_unlock(&f->sem);
make_bad_inode(inode);
iput(inode);
return ERR_PTR(ret);
}
set_nlink(inode, 1);
inode->i_ino = je32_to_cpu(ri->ino);
inode->i_mode = jemode_to_cpu(ri->mode);
i_gid_write(inode, je16_to_cpu(ri->gid));
i_uid_write(inode, je16_to_cpu(ri->uid));
inode->i_atime = inode->i_ctime = inode->i_mtime = current_time(inode);
ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));
inode->i_blocks = 0;
inode->i_size = 0;
if (insert_inode_locked(inode) < 0) {
mutex_unlock(&f->sem);
make_bad_inode(inode);
iput(inode);
return ERR_PTR(-EINVAL);
}
return inode;
}
static int calculate_inocache_hashsize(uint32_t flash_size)
{
/*
* Pick a inocache hash size based on the size of the medium.
* Count how many megabytes we're dealing with, apply a hashsize twice
* that size, but rounding down to the usual big powers of 2. And keep
* to sensible bounds.
*/
int size_mb = flash_size / 1024 / 1024;
int hashsize = (size_mb * 2) & ~0x3f;
if (hashsize < INOCACHE_HASHSIZE_MIN)
return INOCACHE_HASHSIZE_MIN;
if (hashsize > INOCACHE_HASHSIZE_MAX)
return INOCACHE_HASHSIZE_MAX;
return hashsize;
}
int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct jffs2_sb_info *c;
struct inode *root_i;
int ret;
size_t blocks;
c = JFFS2_SB_INFO(sb);
/* Do not support the MLC nand */
if (c->mtd->type == MTD_MLCNANDFLASH)
return -EINVAL;
#ifndef CONFIG_JFFS2_FS_WRITEBUFFER
if (c->mtd->type == MTD_NANDFLASH) {
errorf(fc, "Cannot operate on NAND flash unless jffs2 NAND support is compiled in");
return -EINVAL;
}
if (c->mtd->type == MTD_DATAFLASH) {
errorf(fc, "Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in");
return -EINVAL;
}
#endif
c->flash_size = c->mtd->size;
c->sector_size = c->mtd->erasesize;
blocks = c->flash_size / c->sector_size;
/*
* Size alignment check
*/
if ((c->sector_size * blocks) != c->flash_size) {
c->flash_size = c->sector_size * blocks;
infof(fc, "Flash size not aligned to erasesize, reducing to %dKiB",
c->flash_size / 1024);
}
if (c->flash_size < 5*c->sector_size) {
errorf(fc, "Too few erase blocks (%d)",
c->flash_size / c->sector_size);
return -EINVAL;
}
c->cleanmarker_size = sizeof(struct jffs2_unknown_node);
/* NAND (or other bizarre) flash... do setup accordingly */
ret = jffs2_flash_setup(c);
if (ret)
return ret;
c->inocache_hashsize = calculate_inocache_hashsize(c->flash_size);
c->inocache_list = kcalloc(c->inocache_hashsize, sizeof(struct jffs2_inode_cache *), GFP_KERNEL);
if (!c->inocache_list) {
ret = -ENOMEM;
goto out_wbuf;
}
jffs2_init_xattr_subsystem(c);
if ((ret = jffs2_do_mount_fs(c)))
goto out_inohash;
jffs2_dbg(1, "%s(): Getting root inode\n", __func__);
root_i = jffs2_iget(sb, 1);
if (IS_ERR(root_i)) {
jffs2_dbg(1, "get root inode failed\n");
ret = PTR_ERR(root_i);
goto out_root;
}
ret = -ENOMEM;
jffs2_dbg(1, "%s(): d_make_root()\n", __func__);
sb->s_root = d_make_root(root_i);
if (!sb->s_root)
goto out_root;
sb->s_maxbytes = 0xFFFFFFFF;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = JFFS2_SUPER_MAGIC;
sb->s_time_min = 0;
sb->s_time_max = U32_MAX;
if (!sb_rdonly(sb))
jffs2_start_garbage_collect_thread(c);
return 0;
out_root:
jffs2_free_ino_caches(c);
jffs2_free_raw_node_refs(c);
kvfree(c->blocks);
jffs2_clear_xattr_subsystem(c);
out_inohash:
kfree(c->inocache_list);
out_wbuf:
jffs2_flash_cleanup(c);
return ret;
}
void jffs2_gc_release_inode(struct jffs2_sb_info *c,
struct jffs2_inode_info *f)
{
iput(OFNI_EDONI_2SFFJ(f));
}
struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
int inum, int unlinked)
{
struct inode *inode;
struct jffs2_inode_cache *ic;
if (unlinked) {
/* The inode has zero nlink but its nodes weren't yet marked
obsolete. This has to be because we're still waiting for
the final (close() and) iput() to happen.
There's a possibility that the final iput() could have
happened while we were contemplating. In order to ensure
that we don't cause a new read_inode() (which would fail)
for the inode in question, we use ilookup() in this case
instead of iget().
The nlink can't _become_ zero at this point because we're
holding the alloc_sem, and jffs2_do_unlink() would also
need that while decrementing nlink on any inode.
*/
inode = ilookup(OFNI_BS_2SFFJ(c), inum);
if (!inode) {
jffs2_dbg(1, "ilookup() failed for ino #%u; inode is probably deleted.\n",
inum);
spin_lock(&c->inocache_lock);
ic = jffs2_get_ino_cache(c, inum);
if (!ic) {
jffs2_dbg(1, "Inode cache for ino #%u is gone\n",
inum);
spin_unlock(&c->inocache_lock);
return NULL;
}
if (ic->state != INO_STATE_CHECKEDABSENT) {
/* Wait for progress. Don't just loop */
jffs2_dbg(1, "Waiting for ino #%u in state %d\n",
ic->ino, ic->state);
sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
} else {
spin_unlock(&c->inocache_lock);
}
return NULL;
}
} else {
/* Inode has links to it still; they're not going away because
jffs2_do_unlink() would need the alloc_sem and we have it.
Just iget() it, and if read_inode() is necessary that's OK.
*/
inode = jffs2_iget(OFNI_BS_2SFFJ(c), inum);
if (IS_ERR(inode))
return ERR_CAST(inode);
}
if (is_bad_inode(inode)) {
pr_notice("Eep. read_inode() failed for ino #%u. unlinked %d\n",
inum, unlinked);
/* NB. This will happen again. We need to do something appropriate here. */
iput(inode);
return ERR_PTR(-EIO);
}
return JFFS2_INODE_INFO(inode);
}
static int jffs2_flash_setup(struct jffs2_sb_info *c) {
int ret = 0;
if (jffs2_cleanmarker_oob(c)) {
/* NAND flash... do setup accordingly */
ret = jffs2_nand_flash_setup(c);
if (ret)
return ret;
}
/* and Dataflash */
if (jffs2_dataflash(c)) {
ret = jffs2_dataflash_setup(c);
if (ret)
return ret;
}
/* and Intel "Sibley" flash */
if (jffs2_nor_wbuf_flash(c)) {
ret = jffs2_nor_wbuf_flash_setup(c);
if (ret)
return ret;
}
/* and an UBI volume */
if (jffs2_ubivol(c)) {
ret = jffs2_ubivol_setup(c);
if (ret)
return ret;
}
return ret;
}
void jffs2_flash_cleanup(struct jffs2_sb_info *c) {
if (jffs2_cleanmarker_oob(c)) {
jffs2_nand_flash_cleanup(c);
}
/* and DataFlash */
if (jffs2_dataflash(c)) {
jffs2_dataflash_cleanup(c);
}
/* and Intel "Sibley" flash */
if (jffs2_nor_wbuf_flash(c)) {
jffs2_nor_wbuf_flash_cleanup(c);
}
/* and an UBI volume */
if (jffs2_ubivol(c)) {
jffs2_ubivol_cleanup(c);
}
}