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Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r--fs/btrfs/ctree.c132
1 files changed, 83 insertions, 49 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0cc919d15b14..148648ea1c8b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1508,26 +1508,26 @@ static noinline void unlock_up(struct btrfs_path *path, int level,
*/
static int
read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
- struct extent_buffer **eb_ret, int level, int slot,
+ struct extent_buffer **eb_ret, int slot,
const struct btrfs_key *key)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_tree_parent_check check = { 0 };
u64 blocknr;
- u64 gen;
- struct extent_buffer *tmp;
- int ret;
+ struct extent_buffer *tmp = NULL;
+ int ret = 0;
int parent_level;
- bool unlock_up;
+ int err;
+ bool read_tmp = false;
+ bool tmp_locked = false;
+ bool path_released = false;
- unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]);
blocknr = btrfs_node_blockptr(*eb_ret, slot);
- gen = btrfs_node_ptr_generation(*eb_ret, slot);
parent_level = btrfs_header_level(*eb_ret);
btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot);
check.has_first_key = true;
check.level = parent_level - 1;
- check.transid = gen;
+ check.transid = btrfs_node_ptr_generation(*eb_ret, slot);
check.owner_root = btrfs_root_id(root);
/*
@@ -1540,79 +1540,115 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
tmp = find_extent_buffer(fs_info, blocknr);
if (tmp) {
if (p->reada == READA_FORWARD_ALWAYS)
- reada_for_search(fs_info, p, level, slot, key->objectid);
+ reada_for_search(fs_info, p, parent_level, slot, key->objectid);
/* first we do an atomic uptodate check */
- if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) {
+ if (btrfs_buffer_uptodate(tmp, check.transid, 1) > 0) {
/*
* Do extra check for first_key, eb can be stale due to
* being cached, read from scrub, or have multiple
* parents (shared tree blocks).
*/
- if (btrfs_verify_level_key(tmp,
- parent_level - 1, &check.first_key, gen)) {
- free_extent_buffer(tmp);
- return -EUCLEAN;
+ if (btrfs_verify_level_key(tmp, &check)) {
+ ret = -EUCLEAN;
+ goto out;
}
*eb_ret = tmp;
- return 0;
+ tmp = NULL;
+ ret = 0;
+ goto out;
}
if (p->nowait) {
- free_extent_buffer(tmp);
- return -EAGAIN;
+ ret = -EAGAIN;
+ goto out;
}
- if (unlock_up)
- btrfs_unlock_up_safe(p, level + 1);
-
- /* now we're allowed to do a blocking uptodate check */
- ret = btrfs_read_extent_buffer(tmp, &check);
- if (ret) {
- free_extent_buffer(tmp);
+ if (!p->skip_locking) {
+ btrfs_unlock_up_safe(p, parent_level + 1);
+ tmp_locked = true;
+ btrfs_tree_read_lock(tmp);
btrfs_release_path(p);
- return ret;
+ ret = -EAGAIN;
+ path_released = true;
}
- if (unlock_up)
- ret = -EAGAIN;
+ /* Now we're allowed to do a blocking uptodate check. */
+ err = btrfs_read_extent_buffer(tmp, &check);
+ if (err) {
+ ret = err;
+ goto out;
+ }
+ if (ret == 0) {
+ ASSERT(!tmp_locked);
+ *eb_ret = tmp;
+ tmp = NULL;
+ }
goto out;
} else if (p->nowait) {
- return -EAGAIN;
+ ret = -EAGAIN;
+ goto out;
}
- if (unlock_up) {
- btrfs_unlock_up_safe(p, level + 1);
+ if (!p->skip_locking) {
+ btrfs_unlock_up_safe(p, parent_level + 1);
ret = -EAGAIN;
- } else {
- ret = 0;
}
if (p->reada != READA_NONE)
- reada_for_search(fs_info, p, level, slot, key->objectid);
+ reada_for_search(fs_info, p, parent_level, slot, key->objectid);
- tmp = read_tree_block(fs_info, blocknr, &check);
+ tmp = btrfs_find_create_tree_block(fs_info, blocknr, check.owner_root, check.level);
if (IS_ERR(tmp)) {
+ ret = PTR_ERR(tmp);
+ tmp = NULL;
+ goto out;
+ }
+ read_tmp = true;
+
+ if (!p->skip_locking) {
+ ASSERT(ret == -EAGAIN);
+ tmp_locked = true;
+ btrfs_tree_read_lock(tmp);
btrfs_release_path(p);
- return PTR_ERR(tmp);
+ path_released = true;
+ }
+
+ /* Now we're allowed to do a blocking uptodate check. */
+ err = btrfs_read_extent_buffer(tmp, &check);
+ if (err) {
+ ret = err;
+ goto out;
}
+
/*
* If the read above didn't mark this buffer up to date,
* it will never end up being up to date. Set ret to EIO now
* and give up so that our caller doesn't loop forever
* on our EAGAINs.
*/
- if (!extent_buffer_uptodate(tmp))
+ if (!extent_buffer_uptodate(tmp)) {
ret = -EIO;
+ goto out;
+ }
-out:
if (ret == 0) {
+ ASSERT(!tmp_locked);
*eb_ret = tmp;
- } else {
- free_extent_buffer(tmp);
- btrfs_release_path(p);
+ tmp = NULL;
+ }
+out:
+ if (tmp) {
+ if (tmp_locked)
+ btrfs_tree_read_unlock(tmp);
+ if (read_tmp && ret && ret != -EAGAIN)
+ free_extent_buffer_stale(tmp);
+ else
+ free_extent_buffer(tmp);
}
+ if (ret && !path_released)
+ btrfs_release_path(p);
return ret;
}
@@ -2197,8 +2233,8 @@ cow_done:
goto done;
}
- err = read_block_for_search(root, p, &b, level, slot, key);
- if (err == -EAGAIN)
+ err = read_block_for_search(root, p, &b, slot, key);
+ if (err == -EAGAIN && !p->nowait)
goto again;
if (err) {
ret = err;
@@ -2324,8 +2360,8 @@ again:
goto done;
}
- err = read_block_for_search(root, p, &b, level, slot, key);
- if (err == -EAGAIN)
+ err = read_block_for_search(root, p, &b, slot, key);
+ if (err == -EAGAIN && !p->nowait)
goto again;
if (err) {
ret = err;
@@ -2334,7 +2370,7 @@ again:
level = btrfs_header_level(b);
btrfs_tree_read_lock(b);
- b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq);
+ b = btrfs_tree_mod_log_rewind(fs_info, b, time_seq);
if (!b) {
ret = -ENOMEM;
goto done;
@@ -4930,8 +4966,7 @@ again:
}
next = c;
- ret = read_block_for_search(root, path, &next, level,
- slot, &key);
+ ret = read_block_for_search(root, path, &next, slot, &key);
if (ret == -EAGAIN && !path->nowait)
goto again;
@@ -4974,8 +5009,7 @@ again:
if (!level)
break;
- ret = read_block_for_search(root, path, &next, level,
- 0, &key);
+ ret = read_block_for_search(root, path, &next, 0, &key);
if (ret == -EAGAIN && !path->nowait)
goto again;
generated by cgit (git 2.34.1) at 2025-05-29 22:12:44 +0000