From c1b1352f21bcf8c0678c4d4fbfafc4f6729e1daa Mon Sep 17 00:00:00 2001 From: Imran Khan Date: Wed, 4 May 2022 19:51:19 +1000 Subject: kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file. Since we are no longer using refcnt for kernfs_open_node instances, rename kernfs_put_open_node to kernfs_unlink_open_file to reflect this change. Also update function description and inline comments accordingly. Signed-off-by: Imran Khan Link: https://lore.kernel.org/r/20220504095123.295859-2-imran.f.khan@oracle.com Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) (limited to 'fs/kernfs/file.c') diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index aea6968c979e..e3abfa843879 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -552,18 +552,19 @@ static int kernfs_get_open_node(struct kernfs_node *kn, } /** - * kernfs_put_open_node - put kernfs_open_node + * kernfs_unlink_open_file - Unlink @of from @kn. + * * @kn: target kernfs_node * @of: associated kernfs_open_file * - * Put @kn->attr.open and unlink @of from the files list. If - * list of associated open files becomes empty, disassociate and - * free kernfs_open_node. + * Unlink @of from list of @kn's associated open files. If list of + * associated open files becomes empty, disassociate and free + * kernfs_open_node. * * LOCKING: * None. */ -static void kernfs_put_open_node(struct kernfs_node *kn, +static void kernfs_unlink_open_file(struct kernfs_node *kn, struct kernfs_open_file *of) { struct kernfs_open_node *on = kn->attr.open; @@ -703,7 +704,7 @@ static int kernfs_fop_open(struct inode *inode, struct file *file) return 0; err_put_node: - kernfs_put_open_node(kn, of); + kernfs_unlink_open_file(kn, of); err_seq_release: seq_release(inode, file); err_free: @@ -749,7 +750,7 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp) mutex_unlock(&kernfs_open_file_mutex); } - kernfs_put_open_node(kn, of); + kernfs_unlink_open_file(kn, of); seq_release(inode, filp); kfree(of->prealloc_buf); kfree(of); @@ -765,8 +766,15 @@ void kernfs_drain_open_files(struct kernfs_node *kn) if (!(kn->flags & (KERNFS_HAS_MMAP | KERNFS_HAS_RELEASE))) return; - on = kn->attr.open; - if (!on) + /* + * lockless opportunistic check is safe below because no one is adding to + * ->attr.open at this point of time. This check allows early bail out + * if ->attr.open is already NULL. kernfs_unlink_open_file makes + * ->attr.open NULL only while holding kernfs_open_file_mutex so below + * check under kernfs_open_file_mutex will ensure bailing out if + * ->attr.open became NULL while waiting for the mutex. + */ + if (!kn->attr.open) return; mutex_lock(&kernfs_open_file_mutex); @@ -775,6 +783,8 @@ void kernfs_drain_open_files(struct kernfs_node *kn) return; } + on = kn->attr.open; + list_for_each_entry(of, &on->files, list) { struct inode *inode = file_inode(of->file); -- cgit