From 620932cd285208ef3009ac338b1eeed13ccd1753 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Thu, 9 Feb 2023 19:20:09 +0000 Subject: [PATCH] mm/damon/dbgfs: print DAMON debugfs interface deprecation message DAMON debugfs interface has announced to be deprecated after >v5.15 LTS kernel is released. And, v6.1.y has announced to be an LTS[1]. Though the announcement was there for a while, some people might not noticed that so far. Also, some users could depend on it and have problems at movng to the alternative (DAMON sysfs interface). For such cases, warn DAMON debugfs interface deprecation with contacts to ask helps when any DAMON debugfs interface file is opened. [1] https://git.kernel.org/pub/scm/docs/kernel/website.git/commit/?id=332e9121320bc7461b2d3a79665caf153e51732c [sj@kernel.org: split DAMON debugfs file open warning message, per Randy] Link: https://lkml.kernel.org/r/20230209192009.7885-4-sj@kernel.org Link: https://lkml.kernel.org/r/20230210044838.63723-4-sj@kernel.org Link: https://lkml.kernel.org/r/20230209192009.7885-4-sj@kernel.org Signed-off-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton --- mm/damon/dbgfs.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index b3f454a..124f0f8 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -20,6 +20,14 @@ static int dbgfs_nr_ctxs; static struct dentry **dbgfs_dirs; static DEFINE_MUTEX(damon_dbgfs_lock); +static void damon_dbgfs_warn_deprecation(void) +{ + pr_warn_once("DAMON debugfs interface is deprecated, " + "so users should move to DAMON_SYSFS. If you cannot, " + "please report your usecase to damon@lists.linux.dev and " + "linux-mm@kvack.org.\n"); +} + /* * Returns non-empty string on success, negative error code otherwise. */ @@ -711,6 +719,8 @@ out: static int damon_dbgfs_open(struct inode *inode, struct file *file) { + damon_dbgfs_warn_deprecation(); + file->private_data = inode->i_private; return nonseekable_open(inode, file); @@ -1039,15 +1049,24 @@ static ssize_t dbgfs_monitor_on_write(struct file *file, return ret; } +static int damon_dbgfs_static_file_open(struct inode *inode, struct file *file) +{ + damon_dbgfs_warn_deprecation(); + return nonseekable_open(inode, file); +} + static const struct file_operations mk_contexts_fops = { + .open = damon_dbgfs_static_file_open, .write = dbgfs_mk_context_write, }; static const struct file_operations rm_contexts_fops = { + .open = damon_dbgfs_static_file_open, .write = dbgfs_rm_context_write, }; static const struct file_operations monitor_on_fops = { + .open = damon_dbgfs_static_file_open, .read = dbgfs_monitor_on_read, .write = dbgfs_monitor_on_write, }; -- 2.7.4