#include <linux/buffer_head.h> /* for fsync_super() */
#include <linux/mount.h>
#include <linux/security.h>
+#include <linux/syscalls.h>
#include <linux/vfs.h>
#include <linux/writeback.h> /* for the emergency remount stuff */
#include <linux/idr.h>
+#include <linux/kobject.h>
+#include <linux/mutex.h>
+#include <linux/devpts_fs.h>
+#include <linux/proc_fs.h>
#include <asm/uaccess.h>
struct file_system_type *get_fs_type(const char *name);
LIST_HEAD(super_blocks);
-spinlock_t sb_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_SPINLOCK(sb_lock);
/**
* alloc_super - create new superblock
*/
static struct super_block *alloc_super(void)
{
- struct super_block *s = kmalloc(sizeof(struct super_block), GFP_USER);
+ struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER);
static struct super_operations default_op;
if (s) {
- memset(s, 0, sizeof(struct super_block));
if (security_sb_alloc(s)) {
kfree(s);
s = NULL;
INIT_LIST_HEAD(&s->s_files);
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_HEAD(&s->s_anon);
+ INIT_LIST_HEAD(&s->s_inodes);
init_rwsem(&s->s_umount);
- sema_init(&s->s_lock, 1);
+ mutex_init(&s->s_lock);
down_write(&s->s_umount);
s->s_count = S_BIAS;
atomic_set(&s->s_active, 1);
- sema_init(&s->s_vfs_rename_sem,1);
- sema_init(&s->s_dquot.dqio_sem, 1);
- sema_init(&s->s_dquot.dqonoff_sem, 1);
+ mutex_init(&s->s_vfs_rename_mutex);
+ mutex_init(&s->s_dquot.dqio_mutex);
+ mutex_init(&s->s_dquot.dqonoff_mutex);
init_rwsem(&s->s_dquot.dqptr_sem);
init_waitqueue_head(&s->s_wait_unfrozen);
s->s_maxbytes = MAX_NON_LFS;
s->dq_op = sb_dquot_ops;
s->s_qcop = sb_quotactl_ops;
s->s_op = &default_op;
+ s->s_time_gran = 1000000000;
}
out:
return s;
return ret;
}
+/*
+ * Drop a superblock's refcount.
+ * Returns non-zero if the superblock is about to be destroyed and
+ * at least is already removed from super_blocks list, so if we are
+ * making a loop through super blocks then we need to restart.
+ * The caller must hold sb_lock.
+ */
+int __put_super_and_need_restart(struct super_block *sb)
+{
+ /* check for race with generic_shutdown_super() */
+ if (list_empty(&sb->s_list)) {
+ /* super block is removed, need to restart... */
+ __put_super(sb);
+ return 1;
+ }
+ /* can't be the last, since s_list is still in use */
+ sb->s_count--;
+ BUG_ON(sb->s_count == 0);
+ return 0;
+}
+
/**
* put_super - drop a temporary reference to superblock
- * @s: superblock in question
+ * @sb: superblock in question
*
* Drops a temporary reference, frees superblock if there's no
* references left.
if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
s->s_count -= S_BIAS-1;
spin_unlock(&sb_lock);
+ DQUOT_OFF(s);
down_write(&s->s_umount);
fs->kill_sb(s);
put_filesystem(fs);
dput(root);
fsync_super(sb);
lock_super(sb);
- lock_kernel();
sb->s_flags &= ~MS_ACTIVE;
/* bad name - it should be evict_inodes() */
invalidate_inodes(sb);
+ lock_kernel();
if (sop->write_super && sb->s_dirt)
sop->write_super(sb);
/* Forget any remaining inodes */
if (invalidate_inodes(sb)) {
- printk("VFS: Busy inodes after unmount. "
- "Self-destruct in 5 seconds. Have a nice day...\n");
+ printk("VFS: Busy inodes after unmount of %s. "
+ "Self-destruct in 5 seconds. Have a nice day...\n",
+ sb->s_id);
}
unlock_kernel();
unlock_super(sb);
}
spin_lock(&sb_lock);
- list_del(&sb->s_list);
+ /* should be initialized for __put_super_and_need_restart() */
+ list_del_init(&sb->s_list);
list_del(&sb->s_instances);
spin_unlock(&sb_lock);
up_write(&sb->s_umount);
}
s->s_type = type;
strlcpy(s->s_id, type->name, sizeof(s->s_id));
- list_add(&s->s_list, super_blocks.prev);
+ list_add_tail(&s->s_list, &super_blocks);
list_add(&s->s_instances, &type->fs_supers);
spin_unlock(&sb_lock);
get_filesystem(type);
*/
void sync_supers(void)
{
- struct super_block * sb;
-restart:
+ struct super_block *sb;
+
spin_lock(&sb_lock);
- sb = sb_entry(super_blocks.next);
- while (sb != sb_entry(&super_blocks))
+restart:
+ list_for_each_entry(sb, &super_blocks, s_list) {
if (sb->s_dirt) {
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
write_super(sb);
- drop_super(sb);
- goto restart;
- } else
- sb = sb_entry(sb->s_list.next);
+ up_read(&sb->s_umount);
+ spin_lock(&sb_lock);
+ if (__put_super_and_need_restart(sb))
+ goto restart;
+ }
+ }
spin_unlock(&sb_lock);
}
void sync_filesystems(int wait)
{
struct super_block *sb;
- static DECLARE_MUTEX(mutex);
+ static DEFINE_MUTEX(mutex);
- down(&mutex); /* Could be down_interruptible */
+ mutex_lock(&mutex); /* Could be down_interruptible */
spin_lock(&sb_lock);
- for (sb = sb_entry(super_blocks.next); sb != sb_entry(&super_blocks);
- sb = sb_entry(sb->s_list.next)) {
+ list_for_each_entry(sb, &super_blocks, s_list) {
if (!sb->s_op->sync_fs)
continue;
if (sb->s_flags & MS_RDONLY)
continue;
sb->s_need_sync_fs = 1;
}
- spin_unlock(&sb_lock);
restart:
- spin_lock(&sb_lock);
- for (sb = sb_entry(super_blocks.next); sb != sb_entry(&super_blocks);
- sb = sb_entry(sb->s_list.next)) {
+ list_for_each_entry(sb, &super_blocks, s_list) {
if (!sb->s_need_sync_fs)
continue;
sb->s_need_sync_fs = 0;
down_read(&sb->s_umount);
if (sb->s_root && (wait || sb->s_dirt))
sb->s_op->sync_fs(sb, wait);
- drop_super(sb);
- goto restart;
+ up_read(&sb->s_umount);
+ /* restart only when sb is no longer on the list */
+ spin_lock(&sb_lock);
+ if (__put_super_and_need_restart(sb))
+ goto restart;
}
spin_unlock(&sb_lock);
- up(&mutex);
+ mutex_unlock(&mutex);
}
/**
struct super_block * get_super(struct block_device *bdev)
{
- struct list_head *p;
+ struct super_block *sb;
+
if (!bdev)
return NULL;
-rescan:
+
spin_lock(&sb_lock);
- list_for_each(p, &super_blocks) {
- struct super_block *s = sb_entry(p);
- if (s->s_bdev == bdev) {
- s->s_count++;
+rescan:
+ list_for_each_entry(sb, &super_blocks, s_list) {
+ if (sb->s_bdev == bdev) {
+ sb->s_count++;
spin_unlock(&sb_lock);
- down_read(&s->s_umount);
- if (s->s_root)
- return s;
- drop_super(s);
- goto rescan;
+ down_read(&sb->s_umount);
+ if (sb->s_root)
+ return sb;
+ up_read(&sb->s_umount);
+ /* restart only when sb is no longer on the list */
+ spin_lock(&sb_lock);
+ if (__put_super_and_need_restart(sb))
+ goto rescan;
}
}
spin_unlock(&sb_lock);
struct super_block * user_get_super(dev_t dev)
{
- struct list_head *p;
+ struct super_block *sb;
-rescan:
spin_lock(&sb_lock);
- list_for_each(p, &super_blocks) {
- struct super_block *s = sb_entry(p);
- if (s->s_dev == dev) {
- s->s_count++;
+rescan:
+ list_for_each_entry(sb, &super_blocks, s_list) {
+ if (sb->s_dev == dev) {
+ sb->s_count++;
spin_unlock(&sb_lock);
- down_read(&s->s_umount);
- if (s->s_root)
- return s;
- drop_super(s);
- goto rescan;
+ down_read(&sb->s_umount);
+ if (sb->s_root)
+ return sb;
+ up_read(&sb->s_umount);
+ /* restart only when sb is no longer on the list */
+ spin_lock(&sb_lock);
+ if (__put_super_and_need_restart(sb))
+ goto rescan;
}
}
spin_unlock(&sb_lock);
return NULL;
}
-EXPORT_SYMBOL(user_get_super);
-
asmlinkage long sys_ustat(unsigned dev, struct ustat __user * ubuf)
{
struct super_block *s;
struct file *f;
file_list_lock();
- list_for_each_entry(f, &sb->s_files, f_list) {
+ list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
if (S_ISREG(f->f_dentry->d_inode->i_mode) && file_count(f))
f->f_mode &= ~FMODE_WRITE;
}
*/
static struct idr unnamed_dev_idr;
-static spinlock_t unnamed_dev_lock = SPIN_LOCK_UNLOCKED;/* protects the above */
+static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
int set_anon_super(struct super_block *s, void *data)
{
int dev;
+ int error;
- spin_lock(&unnamed_dev_lock);
- if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0) {
- spin_unlock(&unnamed_dev_lock);
+ retry:
+ if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0)
return -ENOMEM;
- }
- dev = idr_get_new(&unnamed_dev_idr, NULL);
+ spin_lock(&unnamed_dev_lock);
+ error = idr_get_new(&unnamed_dev_idr, NULL, &dev);
spin_unlock(&unnamed_dev_lock);
+ if (error == -EAGAIN)
+ /* We raced and lost with another CPU. */
+ goto retry;
+ else if (error)
+ return -EAGAIN;
if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
spin_lock(&unnamed_dev_lock);
return (void *)s->s_bdev == data;
}
+static void bdev_uevent(struct block_device *bdev, enum kobject_action action)
+{
+ if (bdev->bd_disk) {
+ if (bdev->bd_part)
+ kobject_uevent(&bdev->bd_part->kobj, action);
+ else
+ kobject_uevent(&bdev->bd_disk->kobj, action);
+ }
+}
+
struct super_block *get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int))
* will protect the lockfs code from trying to start a snapshot
* while we are mounting
*/
- down(&bdev->bd_mount_sem);
+ mutex_lock(&bdev->bd_mount_mutex);
s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
- up(&bdev->bd_mount_sem);
+ mutex_unlock(&bdev->bd_mount_mutex);
if (IS_ERR(s))
goto out;
s->s_flags = flags;
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
- s->s_old_blocksize = block_size(bdev);
- sb_set_blocksize(s, s->s_old_blocksize);
- error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
+ sb_set_blocksize(s, block_size(bdev));
+ error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
s = ERR_PTR(error);
- } else
+ } else {
s->s_flags |= MS_ACTIVE;
+ bdev_uevent(bdev, KOBJ_MOUNT);
+ }
}
return s;
void kill_block_super(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
+
+ bdev_uevent(bdev, KOBJ_UMOUNT);
generic_shutdown_super(sb);
- set_blocksize(bdev, sb->s_old_blocksize);
+ sync_blockdev(bdev);
close_bdev_excl(bdev);
}
s->s_flags = flags;
- error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
+ error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
return s;
if (!s->s_root) {
s->s_flags = flags;
- error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
+ error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
do_kern_mount(const char *fstype, int flags, const char *name, void *data)
{
struct file_system_type *type = get_fs_type(fstype);
- struct super_block *sb = ERR_PTR(-ENOMEM);
+ struct super_block *sb;
struct vfsmount *mnt;
int error;
char *secdata = NULL;
if (!type)
return ERR_PTR(-ENODEV);
+ sb = ERR_PTR(-EPERM);
+ if ((type->fs_flags & FS_BINARY_MOUNTDATA) &&
+ !vx_capable(CAP_SYS_ADMIN, VXC_BINARY_MOUNT))
+ goto out;
+
+ sb = ERR_PTR(-ENOMEM);
mnt = alloc_vfsmnt(name);
if (!mnt)
goto out;
sb = type->get_sb(type, flags, name, data);
if (IS_ERR(sb))
goto out_free_secdata;
+
+ error = -EPERM;
+ if (!capable(CAP_SYS_ADMIN) && !sb->s_bdev &&
+ (sb->s_magic != PROC_SUPER_MAGIC) &&
+ (sb->s_magic != DEVPTS_SUPER_MAGIC))
+ goto out_sb;
+
error = security_sb_kern_mount(sb, secdata);
if (error)
goto out_sb;
mnt->mnt_mountpoint = sb->s_root;
mnt->mnt_parent = mnt;
up_write(&sb->s_umount);
+ free_secdata(secdata);
put_filesystem(type);
return mnt;
out_sb:
return (struct vfsmount *)sb;
}
+EXPORT_SYMBOL_GPL(do_kern_mount);
+
struct vfsmount *kern_mount(struct file_system_type *type)
{
return do_kern_mount(type->name, 0, type->name, NULL);
git://git.onelab.eu / linux-2.6.git / blobdiff