diff options
| author | SeongJae Park <sj@kernel.org> | 2024-01-29 17:35:42 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-02-22 10:24:45 -0800 |
| commit | f921003b40d107e805b29358fd1035eadae3806c (patch) | |
| tree | cdd868945ac5aca27239b9a847885b774803f60c /mm/damon | |
| parent | f4cba4bf6777b15d934a354e8aa07059112bf2e8 (diff) | |
mm/damon/dbgfs: implement deprecation notice file
Implement a read-only file for DAMON debugfs interface deprecation notice,
to let users who manually read/write the DAMON debugfs files from their
shell command line easily notice the fact.
[arnd@arndb.de: fix bogus string length]
Link: https://lkml.kernel.org/r/20240202124339.892862-1-arnd@kernel.org
Link: https://lkml.kernel.org/r/20240130013549.89538-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/damon')
| -rw-r--r-- | mm/damon/dbgfs.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index 7dac24e69e3b..f66865acb523 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -805,6 +805,17 @@ static void dbgfs_destroy_ctx(struct damon_ctx *ctx) damon_destroy_ctx(ctx); } +static ssize_t damon_dbgfs_deprecated_read(struct file *file, + char __user *buf, size_t count, loff_t *ppos) +{ + static const char kbuf[512] = "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"; + + return simple_read_from_buffer(buf, count, ppos, kbuf, strlen(kbuf)); +} + /* * Make a context of @name and create a debugfs directory for it. * @@ -1056,6 +1067,10 @@ static int damon_dbgfs_static_file_open(struct inode *inode, struct file *file) return nonseekable_open(inode, file); } +static const struct file_operations deprecated_fops = { + .read = damon_dbgfs_deprecated_read, +}; + static const struct file_operations mk_contexts_fops = { .open = damon_dbgfs_static_file_open, .write = dbgfs_mk_context_write, @@ -1076,9 +1091,9 @@ static int __init __damon_dbgfs_init(void) { struct dentry *dbgfs_root; const char * const file_names[] = {"mk_contexts", "rm_contexts", - "monitor_on"}; + "monitor_on", "DEPRECATED"}; const struct file_operations *fops[] = {&mk_contexts_fops, - &rm_contexts_fops, &monitor_on_fops}; + &rm_contexts_fops, &monitor_on_fops, &deprecated_fops}; int i; dbgfs_root = debugfs_create_dir("damon", NULL); |