[PATCH 5.19 1079/1157] btrfs: tree-log: make the return value for log syncing consistent

From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 20:59:49 EST


From: Josef Bacik <josef@xxxxxxxxxxxxxx>

[ Upstream commit f31f09f6be1c6c1a673e0566e258281a7bbaaa51 ]

Currently we will return 1 or -EAGAIN if we decide we need to commit
the transaction rather than sync the log. In practice this doesn't
really matter, we interpret any !0 and !BTRFS_NO_LOG_SYNC as needing to
commit the transaction. However this makes it hard to figure out what
the correct thing to do is.

Fix this up by defining BTRFS_LOG_FORCE_COMMIT and using this in all the
places where we want to force the transaction to be committed.

CC: stable@xxxxxxxxxxxxxxx # 5.15+
Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/btrfs/file.c | 2 +-
fs/btrfs/tree-log.c | 18 +++++++++---------
fs/btrfs/tree-log.h | 3 +++
3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 9dfde1af8a64..89c6d7ff1987 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2308,7 +2308,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
btrfs_release_log_ctx_extents(&ctx);
if (ret < 0) {
/* Fallthrough and commit/free transaction. */
- ret = 1;
+ ret = BTRFS_LOG_FORCE_COMMIT;
}

/* we've logged all the items and now have a consistent
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 370388fadf96..c94713c811bb 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -171,7 +171,7 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
int index = (root->log_transid + 1) % 2;

if (btrfs_need_log_full_commit(trans)) {
- ret = -EAGAIN;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}

@@ -194,7 +194,7 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
* writing.
*/
if (zoned && !created) {
- ret = -EAGAIN;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}

@@ -3121,7 +3121,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,

/* bail out if we need to do a full commit */
if (btrfs_need_log_full_commit(trans)) {
- ret = -EAGAIN;
+ ret = BTRFS_LOG_FORCE_COMMIT;
mutex_unlock(&root->log_mutex);
goto out;
}
@@ -3222,7 +3222,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
}
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
- ret = -EAGAIN;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}

@@ -3261,7 +3261,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
blk_finish_plug(&plug);
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
- ret = -EAGAIN;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto out_wake_log_root;
}

@@ -5848,7 +5848,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
inode_only == LOG_INODE_ALL &&
inode->last_unlink_trans >= trans->transid) {
btrfs_set_log_full_commit(trans);
- ret = 1;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto out_unlock;
}

@@ -6562,12 +6562,12 @@ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
bool log_dentries = false;

if (btrfs_test_opt(fs_info, NOTREELOG)) {
- ret = 1;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto end_no_trans;
}

if (btrfs_root_refs(&root->root_item) == 0) {
- ret = 1;
+ ret = BTRFS_LOG_FORCE_COMMIT;
goto end_no_trans;
}

@@ -6665,7 +6665,7 @@ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
end_trans:
if (ret < 0) {
btrfs_set_log_full_commit(trans);
- ret = 1;
+ ret = BTRFS_LOG_FORCE_COMMIT;
}

if (ret)
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index 1620f8170629..57ab5f3b8dc7 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -12,6 +12,9 @@
/* return value for btrfs_log_dentry_safe that means we don't need to log it at all */
#define BTRFS_NO_LOG_SYNC 256

+/* We can't use the tree log for whatever reason, force a transaction commit */
+#define BTRFS_LOG_FORCE_COMMIT (1)
+
struct btrfs_log_ctx {
int log_ret;
int log_transid;
--
2.35.1