[PATCH 5.15 47/73] btrfs: remove no longer needed logic for replaying directory deletes

Greg Kroah-Hartman
2022-09-02T13:41:20Z

From: Filipe Manana <fdmanana@suse.com>

[ Upstream commit ccae4a19c9140a34a0c5f0658812496dd8bbdeaf ]

Now that we log only dir index keys when logging a directory, we no longer
need to deal with dir item keys in the log replay code for replaying
directory deletes. This is also true for the case when we replay a log
tree created by a kernel that still logs dir items.

So remove the remaining code of the replay of directory deletes algorithm
that deals with dir item keys.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/tree-log.c | 158 ++++++++++++++------------------
include/uapi/linux/btrfs_tree.h | 4 +-
2 files changed, 72 insertions(+), 90 deletions(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 6f51c4d922d48..4ab1bbc344760 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2197,7 +2197,7 @@ static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
*/
static noinline int find_dir_range(struct btrfs_root *root,
struct btrfs_path *path,
- u64 dirid, int key_type,
+ u64 dirid,
u64 *start_ret, u64 *end_ret)
{
struct btrfs_key key;
@@ -2210,7 +2210,7 @@ static noinline int find_dir_range(struct btrfs_root *root,
return 1;

key.objectid = dirid;
- key.type = key_type;
+ key.type = BTRFS_DIR_LOG_INDEX_KEY;
key.offset = *start_ret;

ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
@@ -2224,7 +2224,7 @@ static noinline int find_dir_range(struct btrfs_root *root,
if (ret != 0)
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);

- if (key.type != key_type || key.objectid != dirid) {
+ if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
ret = 1;
goto next;
}
@@ -2251,7 +2251,7 @@ static noinline int find_dir_range(struct btrfs_root *root,

btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);

- if (key.type != key_type || key.objectid != dirid) {
+ if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
ret = 1;
goto out;
}
@@ -2282,95 +2282,82 @@ static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
int ret;
struct extent_buffer *eb;
int slot;
- u32 item_size;
struct btrfs_dir_item *di;
- struct btrfs_dir_item *log_di;
int name_len;
- unsigned long ptr;
- unsigned long ptr_end;
char *name;
- struct inode *inode;
+ struct inode *inode = NULL;
struct btrfs_key location;

-again:
+ /*
+ * Currenly we only log dir index keys. Even if we replay a log created
+ * by an older kernel that logged both dir index and dir item keys, all
+ * we need to do is process the dir index keys, we (and our caller) can
+ * safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY).
+ */
+ ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY);
+
eb = path->nodes[0];
slot = path->slots[0];
- item_size = btrfs_item_size_nr(eb, slot);
- ptr = btrfs_item_ptr_offset(eb, slot);
- ptr_end = ptr + item_size;
- while (ptr < ptr_end) {
- di = (struct btrfs_dir_item *)ptr;
- name_len = btrfs_dir_name_len(eb, di);
- name = kmalloc(name_len, GFP_NOFS);
- if (!name) {
- ret = -ENOMEM;
- goto out;
- }
- read_extent_buffer(eb, name, (unsigned long)(di + 1),
- name_len);
- log_di = NULL;
- if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
- log_di = btrfs_lookup_dir_item(trans, log, log_path,
- dir_key->objectid,
- name, name_len, 0);
- } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
- log_di = btrfs_lookup_dir_index_item(trans, log,
- log_path,
- dir_key->objectid,
- dir_key->offset,
- name, name_len, 0);
- }
- if (!log_di) {
- btrfs_dir_item_key_to_cpu(eb, di, &location);
- btrfs_release_path(path);
- btrfs_release_path(log_path);
- inode = read_one_inode(root, location.objectid);
- if (!inode) {
- kfree(name);
- return -EIO;
- }
+ di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
+ name_len = btrfs_dir_name_len(eb, di);
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name) {
+ ret = -ENOMEM;
+ goto out;
+ }

- ret = link_to_fixup_dir(trans, root,
- path, location.objectid);
- if (ret) {
- kfree(name);
- iput(inode);
- goto out;
- }
+ read_extent_buffer(eb, name, (unsigned long)(di + 1), name_len);

- inc_nlink(inode);
- ret = btrfs_unlink_inode(trans, BTRFS_I(dir),
- BTRFS_I(inode), name, name_len);
- if (!ret)
- ret = btrfs_run_delayed_items(trans);
- kfree(name);
- iput(inode);
- if (ret)
- goto out;
+ if (log) {
+ struct btrfs_dir_item *log_di;

- /* there might still be more names under this key
- * check and repeat if required
- */
- ret = btrfs_search_slot(NULL, root, dir_key, path,
- 0, 0);
- if (ret == 0)
- goto again;
+ log_di = btrfs_lookup_dir_index_item(trans, log, log_path,
+ dir_key->objectid,
+ dir_key->offset,
+ name, name_len, 0);
+ if (IS_ERR(log_di)) {
+ ret = PTR_ERR(log_di);
+ goto out;
+ } else if (log_di) {
+ /* The dentry exists in the log, we have nothing to do. */
ret = 0;
goto out;
- } else if (IS_ERR(log_di)) {
- kfree(name);
- return PTR_ERR(log_di);
}
- btrfs_release_path(log_path);
- kfree(name);
+ }

- ptr = (unsigned long)(di + 1);
- ptr += name_len;
+ btrfs_dir_item_key_to_cpu(eb, di, &location);
+ btrfs_release_path(path);
+ btrfs_release_path(log_path);
+ inode = read_one_inode(root, location.objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
}
- ret = 0;
+
+ ret = link_to_fixup_dir(trans, root, path, location.objectid);
+ if (ret)
+ goto out;
+
+ inc_nlink(inode);
+ ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(inode), name,
+ name_len);
+ if (ret)
+ goto out;
+
+ ret = btrfs_run_delayed_items(trans);
+ if (ret)
+ goto out;
+
+ /*
+ * Unlike dir item keys, dir index keys can only have one name (entry) in
+ * them, as there are no key collisions since each key has a unique offset
+ * (an index number), so we're done.
+ */
out:
btrfs_release_path(path);
btrfs_release_path(log_path);
+ kfree(name);
+ iput(inode);
return ret;
}

@@ -2490,7 +2477,6 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
{
u64 range_start;
u64 range_end;
- int key_type = BTRFS_DIR_LOG_ITEM_KEY;
int ret = 0;
struct btrfs_key dir_key;
struct btrfs_key found_key;
@@ -2498,7 +2484,7 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct inode *dir;

dir_key.objectid = dirid;
- dir_key.type = BTRFS_DIR_ITEM_KEY;
+ dir_key.type = BTRFS_DIR_INDEX_KEY;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
@@ -2512,14 +2498,14 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
btrfs_free_path(log_path);
return 0;
}
-again:
+
range_start = 0;
range_end = 0;
while (1) {
if (del_all)
range_end = (u64)-1;
else {
- ret = find_dir_range(log, path, dirid, key_type,
+ ret = find_dir_range(log, path, dirid,
&range_start, &range_end);
if (ret < 0)
goto out;
@@ -2546,8 +2532,10 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != dirid ||
- found_key.type != dir_key.type)
- goto next_type;
+ found_key.type != dir_key.type) {
+ ret = 0;
+ goto out;
+ }

if (found_key.offset > range_end)
break;
@@ -2566,15 +2554,7 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
break;
range_start = range_end + 1;
}
-
-next_type:
ret = 0;
- if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
- key_type = BTRFS_DIR_LOG_INDEX_KEY;
- dir_key.type = BTRFS_DIR_INDEX_KEY;
- btrfs_release_path(path);
- goto again;
- }
out:
btrfs_release_path(path);
btrfs_free_path(log_path);
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index e1c4c732aabac..5416f1f1a77a8 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -146,7 +146,9 @@

/*
* dir items are the name -> inode pointers in a directory. There is one
- * for every name in a directory.
+ * for every name in a directory. BTRFS_DIR_LOG_ITEM_KEY is no longer used
+ * but it's still defined here for documentation purposes and to help avoid
+ * having its numerical value reused in the future.
*/
#define BTRFS_DIR_LOG_ITEM_KEY 60
#define BTRFS_DIR_LOG_INDEX_KEY 72
--
2.35.1