X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fsuper.c;h=786fe7d72790ac5646197224fc2af88222dade0a;hb=67e55205ec55cc7899f1d783f217961596798419;hp=0a30e51692cf69579bf51670bb2a6f8cb56f0626;hpb=e78c9a004aadebe22306c81d1a7f1d1278dc37f9;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/super.c b/fs/super.c index 0a30e51..786fe7d 100644 --- a/fs/super.c +++ b/fs/super.c @@ -15,12 +15,11 @@ * 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 , 13-JAN-1998 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000 */ -#include #include #include #include @@ -37,29 +36,29 @@ #include /* for the emergency remount stuff */ #include #include +#include +#include +#include #include +#include "internal.h" -void get_filesystem(struct file_system_type *fs); -void put_filesystem(struct file_system_type *fs); -struct file_system_type *get_fs_type(const char *name); - LIST_HEAD(super_blocks); DEFINE_SPINLOCK(sb_lock); /** * alloc_super - create new superblock + * @type: filesystem type superblock should belong to * * Allocates and initializes a new &struct super_block. alloc_super() * returns a pointer new superblock or %NULL if allocation had failed. */ -static struct super_block *alloc_super(void) +static struct super_block *alloc_super(struct file_system_type *type) { - 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; @@ -67,18 +66,43 @@ static struct super_block *alloc_super(void) } INIT_LIST_HEAD(&s->s_dirty); INIT_LIST_HEAD(&s->s_io); + INIT_LIST_HEAD(&s->s_more_io); 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_LIST_HEAD(&s->s_dentry_lru); + INIT_LIST_HEAD(&s->s_async_list); init_rwsem(&s->s_umount); - sema_init(&s->s_lock, 1); - down_write(&s->s_umount); + mutex_init(&s->s_lock); + lockdep_set_class(&s->s_umount, &type->s_umount_key); + /* + * The locking rules for s_lock are up to the + * filesystem. For example ext3fs has different + * lock ordering than usbfs: + */ + lockdep_set_class(&s->s_lock, &type->s_lock_key); + /* + * 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); - 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; @@ -100,6 +124,8 @@ out: static inline void destroy_super(struct super_block *s) { security_sb_free(s); + kfree(s->s_subtype); + kfree(s->s_options); kfree(s); } @@ -109,7 +135,7 @@ static inline void destroy_super(struct super_block *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; @@ -171,7 +197,7 @@ void deactivate_super(struct super_block *s) 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); @@ -192,7 +218,7 @@ EXPORT_SYMBOL(deactivate_super); * success, 0 if we had failed (superblock contents was already dead or * dying when grab_super() had been called). */ -static int grab_super(struct super_block *s) +static int grab_super(struct super_block *s) __releases(sb_lock) { s->s_count++; spin_unlock(&sb_lock); @@ -213,6 +239,56 @@ static int grab_super(struct super_block *s) return 0; } +/* + * Superblock locking. We really ought to get rid of these two. + */ +void lock_super(struct super_block * sb) +{ + get_fs_excl(); + mutex_lock(&sb->s_lock); +} + +void unlock_super(struct super_block * sb) +{ + put_fs_excl(); + mutex_unlock(&sb->s_lock); +} + +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); + vfs_dq_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); +} +EXPORT_SYMBOL_GPL(fsync_super); + /** * generic_shutdown_super - common helper for ->kill_sb() * @sb: superblock to kill @@ -222,20 +298,27 @@ static int grab_super(struct super_block *s) * that need destruction out of superblock, call generic_shutdown_super() * and release aforementioned objects. Note: dentries and inodes _are_ * taken care of and do not need specific handling. + * + * Upon calling this function, the filesystem may no longer alter or + * rearrange the set of dentries belonging to this super_block, nor may it + * change the attachments of dentries to inodes. */ void generic_shutdown_super(struct super_block *sb) { - struct dentry *root = sb->s_root; - struct super_operations *sop = sb->s_op; + const struct super_operations *sop = sb->s_op; + - if (root) { - sb->s_root = NULL; - shrink_dcache_parent(root); - shrink_dcache_anon(&sb->s_anon); - dput(root); + if (sb->s_root) { + shrink_dcache_for_umount(sb); fsync_super(sb); lock_super(sb); sb->s_flags &= ~MS_ACTIVE; + + /* + * wait for asynchronous fs operations to finish before going further + */ + async_synchronize_full_domain(&sb->s_async_list); + /* bad name - it should be evict_inodes() */ invalidate_inodes(sb); lock_kernel(); @@ -247,8 +330,9 @@ void generic_shutdown_super(struct super_block *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(); @@ -277,25 +361,27 @@ struct super_block *sget(struct file_system_type *type, 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); - s = alloc_super(); + s = alloc_super(type); if (!s) return ERR_PTR(-ENOMEM); goto retry; @@ -304,6 +390,7 @@ retry: err = set(s, data); if (err) { spin_unlock(&sb_lock); + up_write(&s->s_umount); destroy_super(s); return ERR_PTR(err); } @@ -362,7 +449,7 @@ restart: } /* - * Call the ->sync_fs super_op against all filesytems which are r/w and + * Call the ->sync_fs super_op against all filesystems which are r/w and * which implement it. * * This operation is careful to avoid the livelock which could easily happen @@ -370,7 +457,7 @@ restart: * 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 + * But if process A is currently running sync_filesystems 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. @@ -380,9 +467,9 @@ restart: 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); list_for_each_entry(sb, &super_blocks, s_list) { if (!sb->s_op->sync_fs) @@ -402,6 +489,7 @@ restart: sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); + async_synchronize_full_domain(&sb->s_async_list); if (sb->s_root && (wait || sb->s_dirt)) sb->s_op->sync_fs(sb, wait); up_read(&sb->s_umount); @@ -411,7 +499,7 @@ restart: goto restart; } spin_unlock(&sb_lock); - up(&mutex); + mutex_unlock(&mutex); } /** @@ -475,7 +563,7 @@ rescan: 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; @@ -485,7 +573,7 @@ asmlinkage long sys_ustat(unsigned dev, struct ustat __user * ubuf) s = user_get_super(new_decode_dev(dev)); if (s == NULL) goto out; - err = vfs_statfs(s, &sbuf); + err = vfs_statfs(s->s_root, &sbuf); drop_super(s); if (err) goto out; @@ -500,21 +588,40 @@ out: } /** - * mark_files_ro + * mark_files_ro - mark all files read-only * @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 + * 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; +retry: file_list_lock(); 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; + struct vfsmount *mnt; + if (!S_ISREG(f->f_path.dentry->d_inode->i_mode)) + continue; + if (!file_count(f)) + continue; + if (!(f->f_mode & FMODE_WRITE)) + continue; + f->f_mode &= ~FMODE_WRITE; + if (file_check_writeable(f) != 0) + continue; + file_release_write(f); + mnt = mntget(f->f_path.mnt); + file_list_unlock(); + /* + * This can sleep, so we can't hold + * the file_list_lock() spinlock. + */ + mnt_drop_write(mnt); + mntput(mnt); + goto retry; } file_list_unlock(); } @@ -531,9 +638,12 @@ static void mark_files_ro(struct super_block *sb) 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)) return -EACCES; +#endif if (flags & MS_RDONLY) acct_auto_close(sb); shrink_dcache_sb(sb); @@ -546,7 +656,11 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) 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); @@ -556,10 +670,12 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) 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; @@ -582,12 +698,19 @@ static void do_emergency_remount(unsigned long foo) 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); + } } /* @@ -595,7 +718,7 @@ void emergency_remount(void) * 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) @@ -604,10 +727,10 @@ 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. */ @@ -617,7 +740,7 @@ int set_anon_super(struct super_block *s, void *data) 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; } @@ -633,17 +756,12 @@ void kill_anon_super(struct super_block *sb) 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) @@ -653,6 +771,47 @@ void kill_litter_super(struct super_block *sb) 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) { + up_write(&sb->s_umount); + deactivate_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) { s->s_bdev = data; @@ -665,17 +824,22 @@ static int test_bdev_super(struct super_block *s, void *data) return (void *)s->s_bdev == data; } -struct super_block *get_sb_bdev(struct file_system_type *fs_type, +int 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)) + int (*fill_super)(struct super_block *, void *, int), + struct vfsmount *mnt) { 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 (struct super_block *)bdev; + return PTR_ERR(bdev); /* * once the super is inserted into the list by sget, s_umount @@ -686,35 +850,44 @@ struct super_block *get_sb_bdev(struct file_system_type *fs_type, s = sget(fs_type, test_bdev_super, set_bdev_super, bdev); up(&bdev->bd_mount_sem); if (IS_ERR(s)) - goto out; + goto error_s; if (s->s_root) { if ((flags ^ s->s_flags) & MS_RDONLY) { up_write(&s->s_umount); deactivate_super(s); - s = ERR_PTR(-EBUSY); + error = -EBUSY; + goto error_bdev; } - goto out; + + 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_VERBOSE ? 1 : 0); + 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 - s->s_flags |= MS_ACTIVE; + goto error; + } + + s->s_flags |= MS_ACTIVE; + bdev->bd_super = s; } - return s; + simple_set_mnt(mnt, s); + return 0; -out: - close_bdev_excl(bdev); - return s; +error_s: + error = PTR_ERR(s); +error_bdev: + close_bdev_exclusive(bdev, mode); +error: + return error; } EXPORT_SYMBOL(get_sb_bdev); @@ -722,34 +895,39 @@ EXPORT_SYMBOL(get_sb_bdev); void kill_block_super(struct super_block *sb) { struct block_device *bdev = sb->s_bdev; + fmode_t mode = sb->s_mode; + bdev->bd_super = 0; generic_shutdown_super(sb); sync_blockdev(bdev); - close_bdev_excl(bdev); + close_bdev_exclusive(bdev, mode); } EXPORT_SYMBOL(kill_block_super); +#endif -struct super_block *get_sb_nodev(struct file_system_type *fs_type, +int get_sb_nodev(struct file_system_type *fs_type, int flags, void *data, - int (*fill_super)(struct super_block *, void *, int)) + int (*fill_super)(struct super_block *, void *, int), + struct vfsmount *mnt) { int error; struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL); if (IS_ERR(s)) - return s; + return PTR_ERR(s); 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 ERR_PTR(error); + return error; } s->s_flags |= MS_ACTIVE; - return s; + simple_set_mnt(mnt, s); + return 0; } EXPORT_SYMBOL(get_sb_nodev); @@ -759,94 +937,129 @@ static int compare_single(struct super_block *s, void *p) return 1; } -struct super_block *get_sb_single(struct file_system_type *fs_type, +int get_sb_single(struct file_system_type *fs_type, int flags, void *data, - int (*fill_super)(struct super_block *, void *, int)) + int (*fill_super)(struct super_block *, void *, int), + struct vfsmount *mnt) { struct super_block *s; int error; s = sget(fs_type, compare_single, set_anon_super, NULL); if (IS_ERR(s)) - return s; + return PTR_ERR(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); - return ERR_PTR(error); + return error; } s->s_flags |= MS_ACTIVE; } do_remount_sb(s, flags, data, 0); - return s; + simple_set_mnt(mnt, s); + return 0; } EXPORT_SYMBOL(get_sb_single); struct vfsmount * -do_kern_mount(const char *fstype, int flags, const char *name, void *data) +vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data) { - struct file_system_type *type = get_fs_type(fstype); - struct super_block *sb = ERR_PTR(-ENOMEM); struct vfsmount *mnt; - int error; char *secdata = NULL; + int error; if (!type) return ERR_PTR(-ENODEV); + error = -ENOMEM; mnt = alloc_vfsmnt(name); if (!mnt) goto out; - if (data) { + if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) { secdata = alloc_secdata(); - if (!secdata) { - sb = ERR_PTR(-ENOMEM); + if (!secdata) goto out_mnt; - } - error = security_sb_copy_data(type, data, secdata); - if (error) { - sb = ERR_PTR(error); + error = security_sb_copy_data(data, secdata); + if (error) goto out_free_secdata; - } } - sb = type->get_sb(type, flags, name, data); - if (IS_ERR(sb)) + error = type->get_sb(type, flags, name, data, mnt); + if (error < 0) goto out_free_secdata; - error = security_sb_kern_mount(sb, secdata); + BUG_ON(!mnt->mnt_sb); + + error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata); if (error) goto out_sb; - mnt->mnt_sb = sb; - mnt->mnt_root = dget(sb->s_root); - mnt->mnt_mountpoint = sb->s_root; + + mnt->mnt_mountpoint = mnt->mnt_root; mnt->mnt_parent = mnt; - up_write(&sb->s_umount); + up_write(&mnt->mnt_sb->s_umount); free_secdata(secdata); - put_filesystem(type); return mnt; out_sb: - up_write(&sb->s_umount); - deactivate_super(sb); - sb = ERR_PTR(error); + dput(mnt->mnt_root); + up_write(&mnt->mnt_sb->s_umount); + deactivate_super(mnt->mnt_sb); out_free_secdata: free_secdata(secdata); out_mnt: free_vfsmnt(mnt); out: - put_filesystem(type); - return (struct vfsmount *)sb; + return ERR_PTR(error); +} + +EXPORT_SYMBOL_GPL(vfs_kern_mount); + +static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype) +{ + int err; + const char *subtype = strchr(fstype, '.'); + if (subtype) { + subtype++; + err = -EINVAL; + if (!subtype[0]) + goto err; + } else + subtype = ""; + + mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL); + err = -ENOMEM; + if (!mnt->mnt_sb->s_subtype) + goto err; + return mnt; + + err: + mntput(mnt); + return ERR_PTR(err); } +struct vfsmount * +do_kern_mount(const char *fstype, int flags, const char *name, void *data) +{ + struct file_system_type *type = get_fs_type(fstype); + struct vfsmount *mnt; + if (!type) + return ERR_PTR(-ENODEV); + mnt = vfs_kern_mount(type, flags, name, data); + if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) && + !mnt->mnt_sb->s_subtype) + mnt = fs_set_subtype(mnt, fstype); + 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 do_kern_mount(type->name, 0, type->name, NULL); + return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data); } -EXPORT_SYMBOL(kern_mount); +EXPORT_SYMBOL_GPL(kern_mount_data);