archives/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-03-08 04:04:43 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

xfs: use WRITE_ONCE/READ_ONCE for m_errortag

Browse source 
There is no synchronization for updating m_errortag, which is fine as
it's just a debug tool.  It would still be nice to fully avoid the
theoretical case of torn values, so use WRITE_ONCE and READ_ONCE to
access the members.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
This commit is contained in:
Christoph Hellwig 2026-01-30 06:19:20 +01:00 • committed by Carlos Maiolino
parent e2d62bfd99
commit 4d8f42466a
1 changed files with 14 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

23
fs/xfs/xfs_error.c
View file

@ -50,17 +50,18 @@ xfs_errortag_attr_store(
{
struct xfs_mount *mp = to_mp(kobject);
unsigned int error_tag = to_attr(attr)->tag;
unsigned int val;
int ret;
if (strcmp(buf, "default") == 0) {
mp->m_errortag[error_tag] =
xfs_errortag_random_default[error_tag];
val = xfs_errortag_random_default[error_tag];
} else {
ret = kstrtouint(buf, 0, &mp->m_errortag[error_tag]);
ret = kstrtouint(buf, 0, &val);
if (ret)
return ret;
}
WRITE_ONCE(mp->m_errortag[error_tag], val);
return count;
}
@ -71,9 +72,9 @@ xfs_errortag_attr_show(
char *buf)
{
struct xfs_mount *mp = to_mp(kobject);
unsigned int error_tag = to_attr(attr)->tag;
return snprintf(buf, PAGE_SIZE, "%u\n", mp->m_errortag[error_tag]);
return snprintf(buf, PAGE_SIZE, "%u\n",
READ_ONCE(mp->m_errortag[to_attr(attr)->tag]));
}
static const struct sysfs_ops xfs_errortag_sysfs_ops = {
@ -134,7 +135,7 @@ xfs_errortag_test(
{
unsigned int randfactor;
randfactor = mp->m_errortag[error_tag];
randfactor = READ_ONCE(mp->m_errortag[error_tag]);
if (!randfactor || get_random_u32_below(randfactor))
return false;
@ -151,7 +152,7 @@ xfs_errortag_delay(
int line,
unsigned int error_tag)
{
unsigned int delay = mp->m_errortag[error_tag];
unsigned int delay = READ_ONCE(mp->m_errortag[error_tag]);
might_sleep();
@ -183,7 +184,8 @@ xfs_errortag_add(
break;
}
mp->m_errortag[error_tag] = xfs_errortag_random_default[error_tag];
WRITE_ONCE(mp->m_errortag[error_tag],
xfs_errortag_random_default[error_tag]);
return 0;
}
@ -191,7 +193,10 @@ int
xfs_errortag_clearall(
struct xfs_mount *mp)
{
memset(mp->m_errortag, 0, sizeof(unsigned int) * XFS_ERRTAG_MAX);
unsigned int i;
for (i = 0; i < XFS_ERRTAG_MAX; i++)
WRITE_ONCE(mp->m_errortag[i], 0);
return 0;
}
#endif /* DEBUG */