From: Anthony Iliopoulos <ailiop@xxxxxxxx>
Subject: mount: warn only once about timestamp range expiration
Commit f8b92ba67c5d ("mount: Add mount warning for impending timestamp
expiry") introduced a mount warning regarding filesystem timestamp limits,
that is printed upon each writable mount or remount.
This can result in a lot of unnecessary messages in the kernel log in
setups where filesystems are being frequently remounted (or mounted
multiple times).
Avoid this by setting a superblock flag which indicates that the warning
has been emitted at least once for any particular mount, as suggested in
[1].
[1] https://lore.kernel.org/CAHk-=wim6VGnxQmjfK_tDg6fbHYKL4EFkmnTjVr9QnRqjDBAeA@xxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20220119202934.26495-1-ailiop@xxxxxxxx
Signed-off-by: Anthony Iliopoulos <ailiop@xxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/namespace.c | 2 ++
include/linux/fs.h | 1 +
2 files changed, 3 insertions(+)
--- a/fs/namespace.c~mount-warn-only-once-about-timestamp-range-expiration
+++ a/fs/namespace.c
@@ -2597,6 +2597,7 @@ static void mnt_warn_timestamp_expiry(st
struct super_block *sb = mnt->mnt_sb;
if (!__mnt_is_readonly(mnt) &&
+ (!(sb->s_iflags & SB_I_TS_EXPIRY_WARNED)) &&
(ktime_get_real_seconds() + TIME_UPTIME_SEC_MAX > sb->s_time_max)) {
char *buf = (char *)__get_free_page(GFP_KERNEL);
char *mntpath = buf ? d_path(mountpoint, buf, PAGE_SIZE) : ERR_PTR(-ENOMEM);
@@ -2611,6 +2612,7 @@ static void mnt_warn_timestamp_expiry(st
tm.tm_year+1900, (unsigned long long)sb->s_time_max);
free_page((unsigned long)buf);
+ sb->s_iflags |= SB_I_TS_EXPIRY_WARNED;
}
}
--- a/include/linux/fs.h~mount-warn-only-once-about-timestamp-range-expiration
+++ a/include/linux/fs.h
@@ -1440,6 +1440,7 @@ extern int send_sigurg(struct fown_struc
#define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */
#define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */
+#define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */
/* Possible states of 'frozen' field */
enum {
_
