diff options
Diffstat (limited to 'fs/super.c')
| -rw-r--r-- | fs/super.c | 148 |
1 files changed, 136 insertions, 12 deletions
diff --git a/fs/super.c b/fs/super.c index 5960578a4076..f627b7c53d2b 100644 --- a/fs/super.c +++ b/fs/super.c @@ -32,6 +32,7 @@ #include <linux/backing-dev.h> #include <linux/rculist_bl.h> #include <linux/cleancache.h> +#include <linux/fscrypt.h> #include <linux/fsnotify.h> #include <linux/lockdep.h> #include <linux/user_namespace.h> @@ -257,6 +258,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, s->s_maxbytes = MAX_NON_LFS; s->s_op = &default_op; s->s_time_gran = 1000000000; + s->s_time_min = TIME64_MIN; + s->s_time_max = TIME64_MAX; s->cleancache_poolid = CLEANCACHE_NO_POOL; s->s_shrink.seeks = DEFAULT_SEEKS; @@ -290,6 +293,7 @@ static void __put_super(struct super_block *s) WARN_ON(s->s_inode_lru.node); WARN_ON(!list_empty(&s->s_mounts)); security_sb_free(s); + fscrypt_sb_free(s); put_user_ns(s->s_user_ns); kfree(s->s_subtype); call_rcu(&s->rcu, destroy_super_rcu); @@ -1160,9 +1164,11 @@ int vfs_get_super(struct fs_context *fc, { int (*test)(struct super_block *, struct fs_context *); struct super_block *sb; + int err; switch (keying) { case vfs_get_single_super: + case vfs_get_single_reconf_super: test = test_single_super; break; case vfs_get_keyed_super: @@ -1180,18 +1186,29 @@ int vfs_get_super(struct fs_context *fc, return PTR_ERR(sb); if (!sb->s_root) { - int err = fill_super(sb, fc); - if (err) { - deactivate_locked_super(sb); - return err; - } + err = fill_super(sb, fc); + if (err) + goto error; sb->s_flags |= SB_ACTIVE; + fc->root = dget(sb->s_root); + } else { + fc->root = dget(sb->s_root); + if (keying == vfs_get_single_reconf_super) { + err = reconfigure_super(fc); + if (err < 0) { + dput(fc->root); + fc->root = NULL; + goto error; + } + } } - BUG_ON(fc->root); - fc->root = dget(sb->s_root); return 0; + +error: + deactivate_locked_super(sb); + return err; } EXPORT_SYMBOL(vfs_get_super); @@ -1211,7 +1228,26 @@ int get_tree_single(struct fs_context *fc, } EXPORT_SYMBOL(get_tree_single); +int get_tree_single_reconf(struct fs_context *fc, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc)) +{ + return vfs_get_super(fc, vfs_get_single_reconf_super, fill_super); +} +EXPORT_SYMBOL(get_tree_single_reconf); + +int get_tree_keyed(struct fs_context *fc, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc), + void *key) +{ + fc->s_fs_info = key; + return vfs_get_super(fc, vfs_get_keyed_super, fill_super); +} +EXPORT_SYMBOL(get_tree_keyed); + #ifdef CONFIG_BLOCK + static int set_bdev_super(struct super_block *s, void *data) { s->s_bdev = data; @@ -1221,6 +1257,99 @@ static int set_bdev_super(struct super_block *s, void *data) return 0; } +static int set_bdev_super_fc(struct super_block *s, struct fs_context *fc) +{ + return set_bdev_super(s, fc->sget_key); +} + +static int test_bdev_super_fc(struct super_block *s, struct fs_context *fc) +{ + return s->s_bdev == fc->sget_key; +} + +/** + * get_tree_bdev - Get a superblock based on a single block device + * @fc: The filesystem context holding the parameters + * @fill_super: Helper to initialise a new superblock + */ +int get_tree_bdev(struct fs_context *fc, + int (*fill_super)(struct super_block *, + struct fs_context *)) +{ + struct block_device *bdev; + struct super_block *s; + fmode_t mode = FMODE_READ | FMODE_EXCL; + int error = 0; + + if (!(fc->sb_flags & SB_RDONLY)) + mode |= FMODE_WRITE; + + if (!fc->source) + return invalf(fc, "No source specified"); + + bdev = blkdev_get_by_path(fc->source, mode, fc->fs_type); + if (IS_ERR(bdev)) { + errorf(fc, "%s: Can't open blockdev", fc->source); + return PTR_ERR(bdev); + } + + /* Once the superblock is inserted into the list by sget_fc(), s_umount + * will protect the lockfs code from trying to start a snapshot while + * we are mounting + */ + mutex_lock(&bdev->bd_fsfreeze_mutex); + if (bdev->bd_fsfreeze_count > 0) { + mutex_unlock(&bdev->bd_fsfreeze_mutex); + warnf(fc, "%pg: Can't mount, blockdev is frozen", bdev); + return -EBUSY; + } + + fc->sb_flags |= SB_NOSEC; + fc->sget_key = bdev; + s = sget_fc(fc, test_bdev_super_fc, set_bdev_super_fc); + mutex_unlock(&bdev->bd_fsfreeze_mutex); + if (IS_ERR(s)) + return PTR_ERR(s); + + if (s->s_root) { + /* Don't summarily change the RO/RW state. */ + if ((fc->sb_flags ^ s->s_flags) & SB_RDONLY) { + warnf(fc, "%pg: Can't mount, would change RO state", bdev); + deactivate_locked_super(s); + blkdev_put(bdev, mode); + return -EBUSY; + } + + /* + * s_umount nests inside bd_mutex during + * __invalidate_device(). blkdev_put() acquires + * bd_mutex and can't be called under s_umount. Drop + * s_umount temporarily. This is safe as we're + * holding an active reference. + */ + up_write(&s->s_umount); + blkdev_put(bdev, mode); + down_write(&s->s_umount); + } else { + s->s_mode = mode; + snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); + sb_set_blocksize(s, block_size(bdev)); + error = fill_super(s, fc); + if (error) { + deactivate_locked_super(s); + return error; + } + + s->s_flags |= SB_ACTIVE; + bdev->bd_super = s; + } + + BUG_ON(fc->root); + fc->root = dget(s->s_root); + return 0; +} +EXPORT_SYMBOL(get_tree_bdev); + static int test_bdev_super(struct super_block *s, void *data) { return (void *)s->s_bdev == data; @@ -1426,11 +1555,6 @@ int vfs_get_tree(struct fs_context *fc) sb = fc->root->d_sb; WARN_ON(!sb->s_bdi); - if (fc->subtype && !sb->s_subtype) { - sb->s_subtype = fc->subtype; - fc->subtype = NULL; - } - /* * Write barrier is for super_cache_count(). We place it before setting * SB_BORN as the data dependency between the two functions is the |