* Added kerneld support: Jacques Gelinas and Bjorn Ekwall
* Added change_root: Werner Almesberger & Hans Lermen, Feb '96
* Added options to /proc/mounts:
- * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
+ * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
* Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998
* Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000
*/
#include <linux/blkdev.h>
#include <linux/quotaops.h>
#include <linux/namei.h>
-#include <linux/buffer_head.h> /* for fsync_super() */
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/idr.h>
#include <linux/kobject.h>
#include <linux/mutex.h>
+#include <linux/file.h>
#include <asm/uaccess.h>
+#include "internal.h"
LIST_HEAD(super_blocks);
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
+ INIT_LIST_HEAD(&s->s_dentry_lru);
init_rwsem(&s->s_umount);
mutex_init(&s->s_lock);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
* lock ordering than usbfs:
*/
lockdep_set_class(&s->s_lock, &type->s_lock_key);
- down_write(&s->s_umount);
+ /*
+ * sget() can have s_umount recursion.
+ *
+ * When it cannot find a suitable sb, it allocates a new
+ * one (this one), and tries again to find a suitable old
+ * one.
+ *
+ * In case that succeeds, it will acquire the s_umount
+ * lock of the old one. Since these are clearly distrinct
+ * locks, and this object isn't exposed yet, there's no
+ * risk of deadlocks.
+ *
+ * Annotate this by putting this lock in a different
+ * subclass.
+ */
+ down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
s->s_count = S_BIAS;
atomic_set(&s->s_active, 1);
mutex_init(&s->s_vfs_rename_mutex);
{
security_sb_free(s);
kfree(s->s_subtype);
+ kfree(s->s_options);
kfree(s);
}
* Drop a superblock's refcount. Returns non-zero if the superblock was
* destroyed. The caller must hold sb_lock.
*/
-int __put_super(struct super_block *sb)
+static int __put_super(struct super_block *sb)
{
int ret = 0;
if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
s->s_count -= S_BIAS-1;
spin_unlock(&sb_lock);
- DQUOT_OFF(s);
+ vfs_dq_off(s, 0);
down_write(&s->s_umount);
fs->kill_sb(s);
put_filesystem(fs);
EXPORT_SYMBOL(deactivate_super);
+/**
+ * deactivate_locked_super - drop an active reference to superblock
+ * @s: superblock to deactivate
+ *
+ * Equivalent of up_write(&s->s_umount); deactivate_super(s);, except that
+ * it does not unlock it until it's all over. As the result, it's safe to
+ * use to dispose of new superblock on ->get_sb() failure exits - nobody
+ * will see the sucker until it's all over. Equivalent using up_write +
+ * deactivate_super is safe for that purpose only if superblock is either
+ * safe to use or has NULL ->s_root when we unlock.
+ */
+void deactivate_locked_super(struct super_block *s)
+{
+ struct file_system_type *fs = s->s_type;
+ if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
+ s->s_count -= S_BIAS-1;
+ spin_unlock(&sb_lock);
+ vfs_dq_off(s, 0);
+ fs->kill_sb(s);
+ put_filesystem(fs);
+ put_super(s);
+ } else {
+ up_write(&s->s_umount);
+ }
+}
+
+EXPORT_SYMBOL(deactivate_locked_super);
+
/**
* grab_super - acquire an active reference
* @s: reference we are trying to make active
EXPORT_SYMBOL(lock_super);
EXPORT_SYMBOL(unlock_super);
-/*
- * Write out and wait upon all dirty data associated with this
- * superblock. Filesystem data as well as the underlying block
- * device. Takes the superblock lock. Requires a second blkdev
- * flush by the caller to complete the operation.
- */
-void __fsync_super(struct super_block *sb)
-{
- sync_inodes_sb(sb, 0);
- DQUOT_SYNC(sb);
- lock_super(sb);
- if (sb->s_dirt && sb->s_op->write_super)
- sb->s_op->write_super(sb);
- unlock_super(sb);
- if (sb->s_op->sync_fs)
- sb->s_op->sync_fs(sb, 1);
- sync_blockdev(sb->s_bdev);
- sync_inodes_sb(sb, 1);
-}
-
-/*
- * Write out and wait upon all dirty data associated with this
- * superblock. Filesystem data as well as the underlying block
- * device. Takes the superblock lock.
- */
-int fsync_super(struct super_block *sb)
-{
- __fsync_super(sb);
- return sync_blockdev(sb->s_bdev);
-}
-
/**
* generic_shutdown_super - common helper for ->kill_sb()
* @sb: superblock to kill
{
const struct super_operations *sop = sb->s_op;
+
if (sb->s_root) {
shrink_dcache_for_umount(sb);
- fsync_super(sb);
+ sync_filesystem(sb);
lock_super(sb);
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);
if (sop->put_super)
sop->put_super(sb);
void *data)
{
struct super_block *s = NULL;
- struct list_head *p;
+ struct super_block *old;
int err;
retry:
spin_lock(&sb_lock);
- if (test) list_for_each(p, &type->fs_supers) {
- struct super_block *old;
- old = list_entry(p, struct super_block, s_instances);
- if (!test(old, data))
- continue;
- if (!grab_super(old))
- goto retry;
- if (s)
- destroy_super(s);
- return old;
+ if (test) {
+ list_for_each_entry(old, &type->fs_supers, s_instances) {
+ if (!test(old, data))
+ continue;
+ if (!grab_super(old))
+ goto retry;
+ if (s) {
+ up_write(&s->s_umount);
+ destroy_super(s);
+ }
+ return old;
+ }
}
if (!s) {
spin_unlock(&sb_lock);
err = set(s, data);
if (err) {
spin_unlock(&sb_lock);
+ up_write(&s->s_umount);
destroy_super(s);
return ERR_PTR(err);
}
EXPORT_SYMBOL(drop_super);
-static inline void write_super(struct super_block *sb)
-{
- lock_super(sb);
- if (sb->s_root && sb->s_dirt)
- if (sb->s_op->write_super)
- sb->s_op->write_super(sb);
- unlock_super(sb);
-}
-
-/*
+/**
+ * sync_supers - helper for periodic superblock writeback
+ *
+ * Call the write_super method if present on all dirty superblocks in
+ * the system. This is for the periodic writeback used by most older
+ * filesystems. For data integrity superblock writeback use
+ * sync_filesystems() instead.
+ *
* Note: check the dirty flag before waiting, so we don't
* hold up the sync while mounting a device. (The newly
* mounted device won't need syncing.)
spin_lock(&sb_lock);
restart:
list_for_each_entry(sb, &super_blocks, s_list) {
- if (sb->s_dirt) {
+ if (sb->s_op->write_super && sb->s_dirt) {
sb->s_count++;
spin_unlock(&sb_lock);
+
down_read(&sb->s_umount);
- write_super(sb);
+ lock_super(sb);
+ if (sb->s_root && sb->s_dirt)
+ sb->s_op->write_super(sb);
+ unlock_super(sb);
up_read(&sb->s_umount);
+
spin_lock(&sb_lock);
if (__put_super_and_need_restart(sb))
goto restart;
spin_unlock(&sb_lock);
}
-/*
- * Call the ->sync_fs super_op against all filesytems which are r/w and
- * which implement it.
- *
- * This operation is careful to avoid the livelock which could easily happen
- * if two or more filesystems are being continuously dirtied. s_need_sync_fs
- * is used only here. We set it against all filesystems and then clear it as
- * we sync them. So redirtied filesystems are skipped.
- *
- * But if process A is currently running sync_filesytems and then process B
- * calls sync_filesystems as well, process B will set all the s_need_sync_fs
- * flags again, which will cause process A to resync everything. Fix that with
- * a local mutex.
- *
- * (Fabian) Avoid sync_fs with clean fs & wait mode 0
- */
-void sync_filesystems(int wait)
-{
- struct super_block *sb;
- static DEFINE_MUTEX(mutex);
-
- mutex_lock(&mutex); /* Could be down_interruptible */
- spin_lock(&sb_lock);
- 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;
- }
-
-restart:
- list_for_each_entry(sb, &super_blocks, s_list) {
- if (!sb->s_need_sync_fs)
- continue;
- sb->s_need_sync_fs = 0;
- if (sb->s_flags & MS_RDONLY)
- continue; /* hm. Was remounted r/o meanwhile */
- sb->s_count++;
- spin_unlock(&sb_lock);
- down_read(&sb->s_umount);
- if (sb->s_root && (wait || sb->s_dirt))
- sb->s_op->sync_fs(sb, wait);
- 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);
- mutex_unlock(&mutex);
-}
-
/**
* get_super - get the superblock of a device
* @bdev: device to get the superblock for
return NULL;
}
-asmlinkage long sys_ustat(unsigned dev, struct ustat __user * ubuf)
+SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
{
struct super_block *s;
struct ustat tmp;
return err;
}
-/**
- * mark_files_ro
- * @sb: superblock in question
- *
- * All files are marked read/only. We don't care about pending
- * delete files so this should be used in 'force' mode only
- */
-
-static void mark_files_ro(struct super_block *sb)
-{
- struct file *f;
-
- file_list_lock();
- list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
- if (S_ISREG(f->f_path.dentry->d_inode->i_mode) && file_count(f))
- f->f_mode &= ~FMODE_WRITE;
- }
- file_list_unlock();
-}
-
/**
* do_remount_sb - asks filesystem to change mount options.
* @sb: superblock in question
int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
{
int retval;
+ int remount_rw;
#ifdef CONFIG_BLOCK
if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
if (flags & MS_RDONLY)
acct_auto_close(sb);
shrink_dcache_sb(sb);
- fsync_super(sb);
+ sync_filesystem(sb);
/* If we are remounting RDONLY and current sb is read/write,
make sure there are no rw files opened */
mark_files_ro(sb);
else if (!fs_may_remount_ro(sb))
return -EBUSY;
+ retval = vfs_dq_off(sb, 1);
+ if (retval < 0 && retval != -ENOSYS)
+ return -EBUSY;
}
+ remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY);
if (sb->s_op->remount_fs) {
lock_super(sb);
return retval;
}
sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK);
+ if (remount_rw)
+ vfs_dq_quota_on_remount(sb);
return 0;
}
-static void do_emergency_remount(unsigned long foo)
+static void do_emergency_remount(struct work_struct *work)
{
struct super_block *sb;
list_for_each_entry(sb, &super_blocks, s_list) {
sb->s_count++;
spin_unlock(&sb_lock);
- down_read(&sb->s_umount);
+ down_write(&sb->s_umount);
if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
/*
* ->remount_fs needs lock_kernel().
do_remount_sb(sb, MS_RDONLY, NULL, 1);
unlock_kernel();
}
- drop_super(sb);
+ up_write(&sb->s_umount);
+ put_super(sb);
spin_lock(&sb_lock);
}
spin_unlock(&sb_lock);
+ kfree(work);
printk("Emergency Remount complete\n");
}
void emergency_remount(void)
{
- pdflush_operation(do_emergency_remount, 0);
+ struct work_struct *work;
+
+ work = kmalloc(sizeof(*work), GFP_ATOMIC);
+ if (work) {
+ INIT_WORK(work, do_emergency_remount);
+ schedule_work(work);
+ }
}
/*
* filesystems which don't use real block-devices. -- jrs
*/
-static struct idr unnamed_dev_idr;
+static DEFINE_IDA(unnamed_dev_ida);
static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
int set_anon_super(struct super_block *s, void *data)
int error;
retry:
- if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0)
+ if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0)
return -ENOMEM;
spin_lock(&unnamed_dev_lock);
- error = idr_get_new(&unnamed_dev_idr, NULL, &dev);
+ error = ida_get_new(&unnamed_dev_ida, &dev);
spin_unlock(&unnamed_dev_lock);
if (error == -EAGAIN)
/* We raced and lost with another CPU. */
if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
spin_lock(&unnamed_dev_lock);
- idr_remove(&unnamed_dev_idr, dev);
+ ida_remove(&unnamed_dev_ida, dev);
spin_unlock(&unnamed_dev_lock);
return -EMFILE;
}
generic_shutdown_super(sb);
spin_lock(&unnamed_dev_lock);
- idr_remove(&unnamed_dev_idr, slot);
+ ida_remove(&unnamed_dev_ida, slot);
spin_unlock(&unnamed_dev_lock);
}
EXPORT_SYMBOL(kill_anon_super);
-void __init unnamed_dev_init(void)
-{
- idr_init(&unnamed_dev_idr);
-}
-
void kill_litter_super(struct super_block *sb)
{
if (sb->s_root)
EXPORT_SYMBOL(kill_litter_super);
+static int ns_test_super(struct super_block *sb, void *data)
+{
+ return sb->s_fs_info == data;
+}
+
+static int ns_set_super(struct super_block *sb, void *data)
+{
+ sb->s_fs_info = data;
+ return set_anon_super(sb, NULL);
+}
+
+int get_sb_ns(struct file_system_type *fs_type, int flags, void *data,
+ int (*fill_super)(struct super_block *, void *, int),
+ struct vfsmount *mnt)
+{
+ struct super_block *sb;
+
+ sb = sget(fs_type, ns_test_super, ns_set_super, data);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
+
+ if (!sb->s_root) {
+ int err;
+ sb->s_flags = flags;
+ err = fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
+ if (err) {
+ deactivate_locked_super(sb);
+ return err;
+ }
+
+ sb->s_flags |= MS_ACTIVE;
+ }
+
+ simple_set_mnt(mnt, sb);
+ return 0;
+}
+
+EXPORT_SYMBOL(get_sb_ns);
+
#ifdef CONFIG_BLOCK
static int set_bdev_super(struct super_block *s, void *data)
{
{
struct block_device *bdev;
struct super_block *s;
+ fmode_t mode = FMODE_READ;
int error = 0;
- bdev = open_bdev_excl(dev_name, flags, fs_type);
+ if (!(flags & MS_RDONLY))
+ mode |= FMODE_WRITE;
+
+ bdev = open_bdev_exclusive(dev_name, mode, fs_type);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
if (s->s_root) {
if ((flags ^ s->s_flags) & MS_RDONLY) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
error = -EBUSY;
goto error_bdev;
}
- close_bdev_excl(bdev);
+ close_bdev_exclusive(bdev, mode);
} else {
char b[BDEVNAME_SIZE];
s->s_flags = flags;
+ s->s_mode = mode;
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
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);
+ deactivate_locked_super(s);
goto error;
}
s->s_flags |= MS_ACTIVE;
+ bdev->bd_super = s;
}
- return simple_set_mnt(mnt, s);
+ simple_set_mnt(mnt, s);
+ return 0;
error_s:
error = PTR_ERR(s);
error_bdev:
- close_bdev_excl(bdev);
+ close_bdev_exclusive(bdev, mode);
error:
return error;
}
void kill_block_super(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
+ fmode_t mode = sb->s_mode;
+ bdev->bd_super = NULL;
generic_shutdown_super(sb);
sync_blockdev(bdev);
- close_bdev_excl(bdev);
+ close_bdev_exclusive(bdev, mode);
}
EXPORT_SYMBOL(kill_block_super);
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
return error;
}
s->s_flags |= MS_ACTIVE;
- return simple_set_mnt(mnt, s);
+ simple_set_mnt(mnt, s);
+ return 0;
}
EXPORT_SYMBOL(get_sb_nodev);
s->s_flags = flags;
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
- up_write(&s->s_umount);
- deactivate_super(s);
+ deactivate_locked_super(s);
return error;
}
s->s_flags |= MS_ACTIVE;
}
do_remount_sb(s, flags, data, 0);
- return simple_set_mnt(mnt, s);
+ simple_set_mnt(mnt, s);
+ return 0;
}
EXPORT_SYMBOL(get_sb_single);
if (!mnt)
goto out;
- if (data) {
+ if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
secdata = alloc_secdata();
if (!secdata)
goto out_mnt;
- error = security_sb_copy_data(type, data, secdata);
+ error = security_sb_copy_data(data, secdata);
if (error)
goto out_free_secdata;
}
goto out_free_secdata;
BUG_ON(!mnt->mnt_sb);
- error = security_sb_kern_mount(mnt->mnt_sb, secdata);
+ error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata);
if (error)
goto out_sb;
return mnt;
out_sb:
dput(mnt->mnt_root);
- up_write(&mnt->mnt_sb->s_umount);
- deactivate_super(mnt->mnt_sb);
+ deactivate_locked_super(mnt->mnt_sb);
out_free_secdata:
free_secdata(secdata);
out_mnt:
put_filesystem(type);
return mnt;
}
+EXPORT_SYMBOL_GPL(do_kern_mount);
-struct vfsmount *kern_mount(struct file_system_type *type)
+struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
{
- return vfs_kern_mount(type, 0, type->name, NULL);
+ return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
}
-EXPORT_SYMBOL(kern_mount);
+EXPORT_SYMBOL_GPL(kern_mount_data);
Code Review / linux-2.6.git / blobdiff