int ret;
int i;
- ASSERT(!path->nowait);
+ /*
+ * The nowait semantics are used only for write paths, where we don't
+ * use the tree mod log and sequence numbers.
+ */
+ if (time_seq)
+ ASSERT(!path->nowait);
nritems = btrfs_header_nritems(path->nodes[0]);
if (nritems == 0)
if (path->need_commit_sem) {
path->need_commit_sem = 0;
need_commit_sem = true;
- down_read(&fs_info->commit_root_sem);
+ if (path->nowait) {
+ if (!down_read_trylock(&fs_info->commit_root_sem)) {
+ ret = -EAGAIN;
+ goto done;
+ }
+ } else {
+ down_read(&fs_info->commit_root_sem);
+ }
}
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
}
next = c;
ret = read_block_for_search(root, path, &next, level,
slot, &key);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN && !path->nowait)
goto again;
if (ret < 0) {
if (!path->skip_locking) {
ret = btrfs_try_tree_read_lock(next);
+ if (!ret && path->nowait) {
+ ret = -EAGAIN;
+ goto done;
+ }
if (!ret && time_seq) {
/*
* If we don't get the lock, we may be racing
ret = read_block_for_search(root, path, &next, level,
0, &key);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN && !path->nowait)
goto again;
if (ret < 0) {
goto done;
}
- if (!path->skip_locking)
- btrfs_tree_read_lock(next);
+ if (!path->skip_locking) {
+ if (path->nowait) {
+ if (!btrfs_try_tree_read_lock(next)) {
+ ret = -EAGAIN;
+ goto done;
+ }
+ } else {
+ btrfs_tree_read_lock(next);
+ }
+ }
}
ret = 0;
done:
}
}
+ btrfs_free_path(path);
+ path = NULL;
if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
ret = -EFAULT;
}
out:
+ btrfs_free_path(path);
+
if (!ret || ret == -EOVERFLOW) {
rootrefs->num_items = found;
/* update min_treeid for next search */
}
kfree(rootrefs);
- btrfs_free_path(path);
return ret;
}
ipath->fspath->val[i] = rel_ptr;
}
+ btrfs_free_path(path);
+ path = NULL;
ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
ipath->fspath, size);
if (ret) {
size = min_t(u32, loi->size, SZ_16M);
}
- path = btrfs_alloc_path();
- if (!path) {
- ret = -ENOMEM;
- goto out;
- }
-
inodes = init_data_container(size);
if (IS_ERR(inodes)) {
ret = PTR_ERR(inodes);
- inodes = NULL;
- goto out;
+ goto out_loi;
}
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
inodes, ignore_offset);
+ btrfs_free_path(path);
if (ret == -EINVAL)
ret = -ENOENT;
if (ret < 0)
ret = -EFAULT;
out:
- btrfs_free_path(path);
kvfree(inodes);
out_loi:
kfree(loi);
dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
dstgroup->rsv_excl = inherit->lim.rsv_excl;
- ret = update_qgroup_limit_item(trans, dstgroup);
- if (ret) {
- qgroup_mark_inconsistent(fs_info);
- btrfs_info(fs_info,
- "unable to update quota limit for %llu",
- dstgroup->qgroupid);
- goto unlock;
- }
+ qgroup_dirty(fs_info, dstgroup);
}
if (srcid) {
u64 ext_len;
u64 clone_len;
u64 clone_data_offset;
+ bool crossed_src_i_size = false;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(clone_root->root, path);
if (key.offset >= clone_src_i_size)
break;
- if (key.offset + ext_len > clone_src_i_size)
+ if (key.offset + ext_len > clone_src_i_size) {
ext_len = clone_src_i_size - key.offset;
+ crossed_src_i_size = true;
+ }
clone_data_offset = btrfs_file_extent_offset(leaf, ei);
if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte) {
ret = send_clone(sctx, offset, clone_len,
clone_root);
}
+ } else if (crossed_src_i_size && clone_len < len) {
+ /*
+ * If we are at i_size of the clone source inode and we
+ * can not clone from it, terminate the loop. This is
+ * to avoid sending two write operations, one with a
+ * length matching clone_len and the final one after
+ * this loop with a length of len - clone_len.
+ *
+ * When using encoded writes (BTRFS_SEND_FLAG_COMPRESSED
+ * was passed to the send ioctl), this helps avoid
+ * sending an encoded write for an offset that is not
+ * sector size aligned, in case the i_size of the source
+ * inode is not sector size aligned. That will make the
+ * receiver fallback to decompression of the data and
+ * writing it using regular buffered IO, therefore while
+ * not incorrect, it's not optimal due decompression and
+ * possible re-compression at the receiver.
+ */
+ break;
} else {
ret = send_extent_data(sctx, dst_path, offset,
clone_len);
#ifdef CONFIG_BTRFS_DEBUG
ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
- if (ret)
- goto out2;
+ if (ret) {
+ sysfs_unmerge_group(&btrfs_kset->kobj,
+ &btrfs_static_feature_attr_group);
+ goto out_remove_group;
+ }
#endif
return 0;
u64 *last_old_dentry_offset)
{
struct btrfs_root *log = inode->root->log_root;
- struct extent_buffer *src = path->nodes[0];
- const int nritems = btrfs_header_nritems(src);
+ struct extent_buffer *src;
+ const int nritems = btrfs_header_nritems(path->nodes[0]);
const u64 ino = btrfs_ino(inode);
bool last_found = false;
int batch_start = 0;
int batch_size = 0;
int i;
- for (i = path->slots[0]; i < nritems; i++) {
+ /*
+ * We need to clone the leaf, release the read lock on it, and use the
+ * clone before modifying the log tree. See the comment at copy_items()
+ * about why we need to do this.
+ */
+ src = btrfs_clone_extent_buffer(path->nodes[0]);
+ if (!src)
+ return -ENOMEM;
+
+ i = path->slots[0];
+ btrfs_release_path(path);
+ path->nodes[0] = src;
+ path->slots[0] = i;
+
+ for (; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key key;
int ret;
{
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item *extent;
- struct extent_buffer *src = src_path->nodes[0];
+ struct extent_buffer *src;
int ret = 0;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
const u64 i_size = i_size_read(&inode->vfs_inode);
+ /*
+ * To keep lockdep happy and avoid deadlocks, clone the source leaf and
+ * use the clone. This is because otherwise we would be changing the log
+ * tree, to insert items from the subvolume tree or insert csum items,
+ * while holding a read lock on a leaf from the subvolume tree, which
+ * creates a nasty lock dependency when COWing log tree nodes/leaves:
+ *
+ * 1) Modifying the log tree triggers an extent buffer allocation while
+ * holding a write lock on a parent extent buffer from the log tree.
+ * Allocating the pages for an extent buffer, or the extent buffer
+ * struct, can trigger inode eviction and finally the inode eviction
+ * will trigger a release/remove of a delayed node, which requires
+ * taking the delayed node's mutex;
+ *
+ * 2) Allocating a metadata extent for a log tree can trigger the async
+ * reclaim thread and make us wait for it to release enough space and
+ * unblock our reservation ticket. The reclaim thread can start
+ * flushing delayed items, and that in turn results in the need to
+ * lock delayed node mutexes and in the need to write lock extent
+ * buffers of a subvolume tree - all this while holding a write lock
+ * on the parent extent buffer in the log tree.
+ *
+ * So one task in scenario 1) running in parallel with another task in
+ * scenario 2) could lead to a deadlock, one wanting to lock a delayed
+ * node mutex while having a read lock on a leaf from the subvolume,
+ * while the other is holding the delayed node's mutex and wants to
+ * write lock the same subvolume leaf for flushing delayed items.
+ */
+ src = btrfs_clone_extent_buffer(src_path->nodes[0]);
+ if (!src)
+ return -ENOMEM;
+
+ i = src_path->slots[0];
+ btrfs_release_path(src_path);
+ src_path->nodes[0] = src;
+ src_path->slots[0] = i;
+
ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
nr * sizeof(u32), GFP_NOFS);
if (!ins_data)
super[i] = page_address(page[i]);
}
- if (super[0]->generation > super[1]->generation)
+ if (btrfs_super_generation(super[0]) >
+ btrfs_super_generation(super[1]))
sector = zones[1].start;
else
sector = zones[0].start;
goto out;
}
- zones = kcalloc(BTRFS_REPORT_NR_ZONES, sizeof(struct blk_zone), GFP_KERNEL);
+ zones = kvcalloc(BTRFS_REPORT_NR_ZONES, sizeof(struct blk_zone), GFP_KERNEL);
if (!zones) {
ret = -ENOMEM;
goto out;
}
- kfree(zones);
+ kvfree(zones);
switch (bdev_zoned_model(bdev)) {
case BLK_ZONED_HM:
return 0;
out:
- kfree(zones);
+ kvfree(zones);
out_free_zone_info:
btrfs_destroy_dev_zone_info(device);
projects / linux-block.git / commitdiff