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authorJan Kara <jack@suse.cz>2016-11-23 14:04:55 +0100
committerJan Kara <jack@suse.cz>2016-11-30 08:38:07 +0100
commitc3b004460d77bf3f980d877be539016f2df4df12 (patch)
tree3000d941e7b3ac2fd3ea20d625a384dc4a28a977 /fs/quota
parent5f530de63cfc6ca8571cbdf58af63fb166cc6517 (diff)
downloadlinux-c3b004460d77bf3f980d877be539016f2df4df12.tar.bz2
quota: Remove dqonoff_mutex
The only places that were grabbing dqonoff_mutex are functions turning quotas on and off and these are properly serialized using s_umount semaphore. Remove dqonoff_mutex. Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/quota')
-rw-r--r--fs/quota/dquot.c80
1 files changed, 23 insertions, 57 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index d91aecc939c9..550f78f2b7c7 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -119,8 +119,7 @@
* spinlock to internal buffers before writing.
*
* Lock ordering (including related VFS locks) is the following:
- * dqonoff_mutex > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex
- * dqonoff_mutex > i_mutex comes from dquot_quota_sync, dquot_enable, etc.
+ * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex
*/
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
@@ -933,7 +932,7 @@ static int dqinit_needed(struct inode *inode, int type)
return 0;
}
-/* This routine is guarded by dqonoff_mutex mutex */
+/* This routine is guarded by s_umount semaphore */
static void add_dquot_ref(struct super_block *sb, int type)
{
struct inode *inode, *old_inode = NULL;
@@ -2108,18 +2107,14 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
DQUOT_USAGE_ENABLED)))
return -EINVAL;
- /* We need to serialize quota_off() for device */
- mutex_lock(&dqopt->dqonoff_mutex);
-
/*
* Skip everything if there's nothing to do. We have to do this because
* sometimes we are called when fill_super() failed and calling
* sync_fs() in such cases does no good.
*/
- if (!sb_any_quota_loaded(sb)) {
- mutex_unlock(&dqopt->dqonoff_mutex);
+ if (!sb_any_quota_loaded(sb))
return 0;
- }
+
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
toputinode[cnt] = NULL;
if (type != -1 && cnt != type)
@@ -2173,7 +2168,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
dqopt->info[cnt].dqi_bgrace = 0;
dqopt->ops[cnt] = NULL;
}
- mutex_unlock(&dqopt->dqonoff_mutex);
/* Skip syncing and setting flags if quota files are hidden */
if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
@@ -2191,19 +2185,13 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
* changes done by userspace on the next quotaon() */
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
if (toputinode[cnt]) {
- mutex_lock(&dqopt->dqonoff_mutex);
- /* If quota was reenabled in the meantime, we have
- * nothing to do */
- if (!sb_has_quota_loaded(sb, cnt)) {
- inode_lock(toputinode[cnt]);
- toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
+ WARN_ON_ONCE(sb_has_quota_loaded(sb, cnt));
+ inode_lock(toputinode[cnt]);
+ toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |
S_NOATIME | S_NOQUOTA);
- truncate_inode_pages(&toputinode[cnt]->i_data,
- 0);
- inode_unlock(toputinode[cnt]);
- mark_inode_dirty_sync(toputinode[cnt]);
- }
- mutex_unlock(&dqopt->dqonoff_mutex);
+ truncate_inode_pages(&toputinode[cnt]->i_data, 0);
+ inode_unlock(toputinode[cnt]);
+ mark_inode_dirty_sync(toputinode[cnt]);
}
if (sb->s_bdev)
invalidate_bdev(sb->s_bdev);
@@ -2275,6 +2263,10 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
error = -EINVAL;
goto out_fmt;
}
+ if (sb_has_quota_loaded(sb, type)) {
+ error = -EBUSY;
+ goto out_fmt;
+ }
if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
/* As we bypass the pagecache we must now flush all the
@@ -2286,11 +2278,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
sync_filesystem(sb);
invalidate_bdev(sb->s_bdev);
}
- mutex_lock(&dqopt->dqonoff_mutex);
- if (sb_has_quota_loaded(sb, type)) {
- error = -EBUSY;
- goto out_lock;
- }
if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {
/* We don't want quota and atime on quota files (deadlocks
@@ -2311,7 +2298,7 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
error = -EIO;
dqopt->files[type] = igrab(inode);
if (!dqopt->files[type])
- goto out_lock;
+ goto out_file_flags;
error = -EINVAL;
if (!fmt->qf_ops->check_quota_file(sb, type))
goto out_file_init;
@@ -2334,14 +2321,13 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
spin_unlock(&dq_state_lock);
add_dquot_ref(sb, type);
- mutex_unlock(&dqopt->dqonoff_mutex);
return 0;
out_file_init:
dqopt->files[type] = NULL;
iput(inode);
-out_lock:
+out_file_flags:
if (oldflags != -1) {
inode_lock(inode);
/* Set the flags back (in the case of accidental quotaon()
@@ -2350,7 +2336,6 @@ out_lock:
inode->i_flags |= oldflags;
inode_unlock(inode);
}
- mutex_unlock(&dqopt->dqonoff_mutex);
out_fmt:
put_quota_format(fmt);
@@ -2372,12 +2357,9 @@ int dquot_resume(struct super_block *sb, int type)
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (type != -1 && cnt != type)
continue;
-
- mutex_lock(&dqopt->dqonoff_mutex);
- if (!sb_has_quota_suspended(sb, cnt)) {
- mutex_unlock(&dqopt->dqonoff_mutex);
+ if (!sb_has_quota_suspended(sb, cnt))
continue;
- }
+
inode = dqopt->files[cnt];
dqopt->files[cnt] = NULL;
spin_lock(&dq_state_lock);
@@ -2386,7 +2368,6 @@ int dquot_resume(struct super_block *sb, int type)
cnt);
dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
spin_unlock(&dq_state_lock);
- mutex_unlock(&dqopt->dqonoff_mutex);
flags = dquot_generic_flag(flags, cnt);
ret = vfs_load_quota_inode(inode, cnt,
@@ -2422,9 +2403,7 @@ EXPORT_SYMBOL(dquot_quota_on);
int dquot_enable(struct inode *inode, int type, int format_id,
unsigned int flags)
{
- int ret = 0;
struct super_block *sb = inode->i_sb;
- struct quota_info *dqopt = sb_dqopt(sb);
/* Just unsuspend quotas? */
BUG_ON(flags & DQUOT_SUSPENDED);
@@ -2436,31 +2415,18 @@ int dquot_enable(struct inode *inode, int type, int format_id,
return 0;
/* Just updating flags needed? */
if (sb_has_quota_loaded(sb, type)) {
- mutex_lock(&dqopt->dqonoff_mutex);
- /* Now do a reliable test... */
- if (!sb_has_quota_loaded(sb, type)) {
- mutex_unlock(&dqopt->dqonoff_mutex);
- goto load_quota;
- }
if (flags & DQUOT_USAGE_ENABLED &&
- sb_has_quota_usage_enabled(sb, type)) {
- ret = -EBUSY;
- goto out_lock;
- }
+ sb_has_quota_usage_enabled(sb, type))
+ return -EBUSY;
if (flags & DQUOT_LIMITS_ENABLED &&
- sb_has_quota_limits_enabled(sb, type)) {
- ret = -EBUSY;
- goto out_lock;
- }
+ sb_has_quota_limits_enabled(sb, type))
+ return -EBUSY;
spin_lock(&dq_state_lock);
sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
spin_unlock(&dq_state_lock);
-out_lock:
- mutex_unlock(&dqopt->dqonoff_mutex);
- return ret;
+ return 0;
}
-load_quota:
return vfs_load_quota_inode(inode, type, format_id, flags);
}
EXPORT_SYMBOL(dquot_enable);