ext4: move dcache manipulation out of __ext4_link()

__ext4_link() has two callers.

- ext4_link() calls it during normal handling of the link() system
  call or similar
- ext4_fc_replay_link_internal() calls it when replaying the journal
  at mount time.

The former needs changes to dcache - instantiating the dentry to the
inode on success.  The latter doesn't need or want any dcache
manipulation.

So move the manipulation out of __ext4_link() and do it in ext4_link()
only.

This requires:
 - passing the qname from the dentry explicitly to __ext4_link.
   The parent dir is already passed.  The dentry is still passed
   in the ext4_link() case purely for use by ext4_fc_track_link().
 - passing the inode separately to ext4_fc_track_link() as the
   dentry will not be instantiated yet.
 - using __ext4_add_entry() in ext4_link, which doesn't need a dentry.
 - moving ihold(), d_instantiate(), drop_nlink() and iput() calls out
   of __ext4_link() into ext4_link().

Note that ext4_inc_count() and drop_nlink() remain in __ext4_link()
as both callers need them and they are not related to the dentry.

This substantially simplifies ext4_fc_replay_link_internal(), and
removes a use of d_alloc() which, it is planned, will be removed.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20260320000838.3797494-4-neilb@ownmail.net
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
NeilBrown
2026-03-20 11:03:18 +11:00
committed by Theodore Ts'o
parent 0f5f14f334
commit 52b4fea162
3 changed files with 18 additions and 38 deletions

View File

@@ -2971,7 +2971,8 @@ void __ext4_fc_track_unlink(handle_t *handle, struct inode *inode,
void __ext4_fc_track_link(handle_t *handle, struct inode *inode,
struct dentry *dentry);
void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry);
void ext4_fc_track_link(handle_t *handle, struct dentry *dentry);
void ext4_fc_track_link(handle_t *handle, struct inode *inode,
struct dentry *dentry);
void __ext4_fc_track_create(handle_t *handle, struct inode *inode,
struct dentry *dentry);
void ext4_fc_track_create(handle_t *handle, struct dentry *dentry);
@@ -3716,7 +3717,7 @@ extern int ext4_handle_dirty_dirblock(handle_t *handle, struct inode *inode,
extern int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
struct inode *inode, struct dentry *dentry);
extern int __ext4_link(struct inode *dir, struct inode *inode,
struct dentry *dentry);
const struct qstr *d_name, struct dentry *dentry);
#define S_SHIFT 12
static const unsigned char ext4_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {