@@ -716,6 +716,28 @@ struct btrfs_fs_devices;
struct btrfs_balance_control;
struct btrfs_delayed_root;
+/*
+ * Block group or device which contains an active swapfile. Used for preventing
+ * unsafe operations while a swapfile is active.
+ *
+ * These are sorted on (ptr, inode) (note that a block group or device can
+ * contain more than one swapfile). We compare the pointer values because we
+ * don't actually care what the object is, we just need a quick check whether
+ * the object exists in the rbtree.
+ */
+struct btrfs_swapfile_pin {
+ struct rb_node node;
+ void *ptr;
+ struct inode *inode;
+ /*
+ * If true, ptr points to a struct btrfs_block_group_cache. Otherwise,
+ * ptr points to a struct btrfs_device.
+ */
+ bool is_block_group;
+};
+
+bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
+
#define BTRFS_FS_BARRIER 1
#define BTRFS_FS_CLOSING_START 2
#define BTRFS_FS_CLOSING_DONE 3
@@ -1121,6 +1143,10 @@ struct btrfs_fs_info {
u32 sectorsize;
u32 stripesize;
+ /* Block groups and devices containing active swapfiles. */
+ spinlock_t swapfile_pins_lock;
+ struct rb_root swapfile_pins;
+
#ifdef CONFIG_BTRFS_FS_REF_VERIFY
spinlock_t ref_verify_lock;
struct rb_root block_tree;
@@ -1286,6 +1312,9 @@ struct btrfs_root {
spinlock_t qgroup_meta_rsv_lock;
u64 qgroup_meta_rsv_pertrans;
u64 qgroup_meta_rsv_prealloc;
+
+ /* Number of active swapfiles */
+ atomic_t nr_swapfiles;
};
struct btrfs_file_private {
@@ -414,6 +414,14 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
if (ret)
return ret;
+ if (btrfs_pinned_by_swapfile(fs_info, src_device)) {
+ btrfs_warn_in_rcu(fs_info,
+ "cannot replace device %s (devid %llu) due to active swapfile",
+ btrfs_dev_name(src_device),
+ src_device->devid);
+ return -ETXTBSY;
+ }
+
ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name,
src_device, &tgt_device);
if (ret)
@@ -1188,6 +1188,7 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
refcount_set(&root->refs, 1);
atomic_set(&root->will_be_snapshotted, 0);
atomic_set(&root->snapshot_force_cow, 0);
+ atomic_set(&root->nr_swapfiles, 0);
root->log_transid = 0;
root->log_transid_committed = -1;
root->last_log_commit = 0;
@@ -2782,6 +2783,9 @@ int open_ctree(struct super_block *sb,
fs_info->sectorsize = 4096;
fs_info->stripesize = 4096;
+ spin_lock_init(&fs_info->swapfile_pins_lock);
+ fs_info->swapfile_pins = RB_ROOT;
+
ret = btrfs_alloc_stripe_hash_table(fs_info);
if (ret) {
err = ret;
@@ -290,6 +290,11 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
} else if (fsflags & FS_COMPR_FL) {
const char *comp;
+ if (IS_SWAPFILE(inode)) {
+ ret = -ETXTBSY;
+ goto out_unlock;
+ }
+
binode->flags |= BTRFS_INODE_COMPRESS;
binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
@@ -752,6 +757,12 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
return -EINVAL;
+ if (atomic_read(&root->nr_swapfiles)) {
+ btrfs_warn(fs_info,
+ "cannot snapshot subvolume with active swapfile");
+ return -ETXTBSY;
+ }
+
pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
if (!pending_snapshot)
return -ENOMEM;
@@ -1503,9 +1514,13 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
}
inode_lock(inode);
- if (do_compress)
- BTRFS_I(inode)->defrag_compress = compress_type;
- ret = cluster_pages_for_defrag(inode, pages, i, cluster);
+ if (IS_SWAPFILE(inode)) {
+ ret = -ETXTBSY;
+ } else {
+ if (do_compress)
+ BTRFS_I(inode)->defrag_compress = compress_type;
+ ret = cluster_pages_for_defrag(inode, pages, i, cluster);
+ }
if (ret < 0) {
inode_unlock(inode);
goto out_ra;
@@ -3573,6 +3588,11 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
goto out_unlock;
}
+ if (IS_SWAPFILE(src) || IS_SWAPFILE(dst)) {
+ ret = -ETXTBSY;
+ goto out_unlock;
+ }
+
tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
if (chunk_count == 0)
@@ -4269,6 +4289,11 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
goto out_unlock;
}
+ if (IS_SWAPFILE(src) || IS_SWAPFILE(inode)) {
+ ret = -ETXTBSY;
+ goto out_unlock;
+ }
+
/* determine range to clone */
ret = -EINVAL;
if (off + len > src->i_size || off + len < off)
@@ -4226,6 +4226,7 @@ static void describe_relocation(struct btrfs_fs_info *fs_info,
*/
int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
{
+ struct btrfs_block_group_cache *bg;
struct btrfs_root *extent_root = fs_info->extent_root;
struct reloc_control *rc;
struct inode *inode;
@@ -4234,14 +4235,23 @@ int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
int rw = 0;
int err = 0;
+ bg = btrfs_lookup_block_group(fs_info, group_start);
+ if (!bg)
+ return -ENOENT;
+
+ if (btrfs_pinned_by_swapfile(fs_info, bg)) {
+ btrfs_put_block_group(bg);
+ return -ETXTBSY;
+ }
+
rc = alloc_reloc_control();
- if (!rc)
+ if (!rc) {
+ btrfs_put_block_group(bg);
return -ENOMEM;
+ }
rc->extent_root = extent_root;
-
- rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
- BUG_ON(!rc->block_group);
+ rc->block_group = bg;
ret = btrfs_inc_block_group_ro(rc->block_group);
if (ret) {
@@ -1882,6 +1882,14 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
if (ret)
goto out;
+ if (btrfs_pinned_by_swapfile(fs_info, device)) {
+ btrfs_warn_in_rcu(fs_info,
+ "cannot remove device %s (devid %llu) due to active swapfile",
+ rcu_str_deref(device->name), device->devid);
+ ret = -ETXTBSY;
+ goto out;
+ }
+
if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
ret = BTRFS_ERROR_DEV_TGT_REPLACE;
goto out;
@@ -3626,10 +3634,15 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
ret = btrfs_relocate_chunk(fs_info, found_key.offset);
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
- if (ret && ret != -ENOSPC)
- goto error;
if (ret == -ENOSPC) {
enospc_errors++;
+ } else if (ret == -ETXTBSY) {
+ btrfs_info(fs_info,
+ "skipping relocation of block group %llu due to active swapfile",
+ found_key.offset);
+ ret = 0;
+ } else if (ret) {
+ goto error;
} else {
spin_lock(&fs_info->balance_lock);
bctl->stat.completed++;
@@ -4426,10 +4439,16 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
ret = btrfs_relocate_chunk(fs_info, chunk_offset);
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
- if (ret && ret != -ENOSPC)
- goto done;
- if (ret == -ENOSPC)
+ if (ret == -ENOSPC) {
failed++;
+ } else if (ret) {
+ if (ret == -ETXTBSY) {
+ btrfs_warn(fs_info,
+ "could not shrink block group %llu due to active swapfile",
+ chunk_offset);
+ }
+ goto done;
+ }
} while (key.offset-- > 0);
if (failed && !retried) {
@@ -7530,3 +7549,27 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
btrfs_free_path(path);
return ret;
}
+
+/*
+ * Check whether the given block group or device is pinned by any inode being
+ * used as a swapfile.
+ */
+bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr)
+{
+ struct btrfs_swapfile_pin *sp;
+ struct rb_node *node;
+
+ spin_lock(&fs_info->swapfile_pins_lock);
+ node = fs_info->swapfile_pins.rb_node;
+ while (node) {
+ sp = rb_entry(node, struct btrfs_swapfile_pin, node);
+ if (ptr < sp->ptr)
+ node = node->rb_left;
+ else if (ptr > sp->ptr)
+ node = node->rb_right;
+ else
+ break;
+ }
+ spin_unlock(&fs_info->swapfile_pins_lock);
+ return node != NULL;
+}