summaryrefslogtreecommitdiffstats
path: root/fs/dquot.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/dquot.c')
-rw-r--r--fs/dquot.c167
1 files changed, 97 insertions, 70 deletions
diff --git a/fs/dquot.c b/fs/dquot.c
index 1966c890b48d..acf07e581f8c 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -103,12 +103,12 @@
* (these locking rules also apply for S_NOQUOTA flag in the inode - note that
* for altering the flag i_mutex is also needed). If operation is holding
* reference to dquot in other way (e.g. quotactl ops) it must be guarded by
- * dqonoff_sem.
+ * dqonoff_mutex.
* This locking assures that:
* a) update/access to dquot pointers in inode is serialized
* b) everyone is guarded against invalidate_dquots()
*
- * Each dquot has its dq_lock semaphore. Locked dquots might not be referenced
+ * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
* from inodes (dquot_alloc_space() and such don't check the dq_lock).
* Currently dquot is locked only when it is being read to memory (or space for
* it is being allocated) on the first dqget() and when it is being released on
@@ -118,9 +118,9 @@
* spinlock to internal buffers before writing.
*
* Lock ordering (including related VFS locks) is the following:
- * i_mutex > dqonoff_sem > iprune_sem > journal_lock > dqptr_sem >
- * > dquot->dq_lock > dqio_sem
- * i_mutex on quota files is special (it's below dqio_sem)
+ * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
+ * dqio_mutex
+ * i_mutex on quota files is special (it's below dqio_mutex)
*/
static DEFINE_SPINLOCK(dq_list_lock);
@@ -281,8 +281,8 @@ static inline void remove_inuse(struct dquot *dquot)
static void wait_on_dquot(struct dquot *dquot)
{
- down(&dquot->dq_lock);
- up(&dquot->dq_lock);
+ mutex_lock(&dquot->dq_lock);
+ mutex_unlock(&dquot->dq_lock);
}
#define mark_dquot_dirty(dquot) ((dquot)->dq_sb->dq_op->mark_dirty(dquot))
@@ -321,8 +321,8 @@ int dquot_acquire(struct dquot *dquot)
int ret = 0, ret2 = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
- down(&dquot->dq_lock);
- down(&dqopt->dqio_sem);
+ mutex_lock(&dquot->dq_lock);
+ mutex_lock(&dqopt->dqio_mutex);
if (!test_bit(DQ_READ_B, &dquot->dq_flags))
ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot);
if (ret < 0)
@@ -343,8 +343,8 @@ int dquot_acquire(struct dquot *dquot)
}
set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
out_iolock:
- up(&dqopt->dqio_sem);
- up(&dquot->dq_lock);
+ mutex_unlock(&dqopt->dqio_mutex);
+ mutex_unlock(&dquot->dq_lock);
return ret;
}
@@ -356,7 +356,7 @@ int dquot_commit(struct dquot *dquot)
int ret = 0, ret2 = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
- down(&dqopt->dqio_sem);
+ mutex_lock(&dqopt->dqio_mutex);
spin_lock(&dq_list_lock);
if (!clear_dquot_dirty(dquot)) {
spin_unlock(&dq_list_lock);
@@ -373,7 +373,7 @@ int dquot_commit(struct dquot *dquot)
ret = ret2;
}
out_sem:
- up(&dqopt->dqio_sem);
+ mutex_unlock(&dqopt->dqio_mutex);
return ret;
}
@@ -385,11 +385,11 @@ int dquot_release(struct dquot *dquot)
int ret = 0, ret2 = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
- down(&dquot->dq_lock);
+ mutex_lock(&dquot->dq_lock);
/* Check whether we are not racing with some other dqget() */
if (atomic_read(&dquot->dq_count) > 1)
goto out_dqlock;
- down(&dqopt->dqio_sem);
+ mutex_lock(&dqopt->dqio_mutex);
if (dqopt->ops[dquot->dq_type]->release_dqblk) {
ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot);
/* Write the info */
@@ -399,31 +399,57 @@ int dquot_release(struct dquot *dquot)
ret = ret2;
}
clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
- up(&dqopt->dqio_sem);
+ mutex_unlock(&dqopt->dqio_mutex);
out_dqlock:
- up(&dquot->dq_lock);
+ mutex_unlock(&dquot->dq_lock);
return ret;
}
/* Invalidate all dquots on the list. Note that this function is called after
* quota is disabled and pointers from inodes removed so there cannot be new
- * quota users. Also because we hold dqonoff_sem there can be no quota users
- * for this sb+type at all. */
+ * quota users. There can still be some users of quotas due to inodes being
+ * just deleted or pruned by prune_icache() (those are not attached to any
+ * list). We have to wait for such users.
+ */
static void invalidate_dquots(struct super_block *sb, int type)
{
struct dquot *dquot, *tmp;
+restart:
spin_lock(&dq_list_lock);
list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) {
if (dquot->dq_sb != sb)
continue;
if (dquot->dq_type != type)
continue;
-#ifdef __DQUOT_PARANOIA
- if (atomic_read(&dquot->dq_count))
- BUG();
-#endif
- /* Quota now has no users and it has been written on last dqput() */
+ /* Wait for dquot users */
+ if (atomic_read(&dquot->dq_count)) {
+ DEFINE_WAIT(wait);
+
+ atomic_inc(&dquot->dq_count);
+ prepare_to_wait(&dquot->dq_wait_unused, &wait,
+ TASK_UNINTERRUPTIBLE);
+ spin_unlock(&dq_list_lock);
+ /* Once dqput() wakes us up, we know it's time to free
+ * the dquot.
+ * IMPORTANT: we rely on the fact that there is always
+ * at most one process waiting for dquot to free.
+ * Otherwise dq_count would be > 1 and we would never
+ * wake up.
+ */
+ if (atomic_read(&dquot->dq_count) > 1)
+ schedule();
+ finish_wait(&dquot->dq_wait_unused, &wait);
+ dqput(dquot);
+ /* At this moment dquot() need not exist (it could be
+ * reclaimed by prune_dqcache(). Hence we must
+ * restart. */
+ goto restart;
+ }
+ /*
+ * Quota now has no users and it has been written on last
+ * dqput()
+ */
remove_dquot_hash(dquot);
remove_free_dquot(dquot);
remove_inuse(dquot);
@@ -439,7 +465,7 @@ int vfs_quota_sync(struct super_block *sb, int type)
struct quota_info *dqopt = sb_dqopt(sb);
int cnt;
- down(&dqopt->dqonoff_sem);
+ mutex_lock(&dqopt->dqonoff_mutex);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (type != -1 && cnt != type)
continue;
@@ -474,7 +500,7 @@ int vfs_quota_sync(struct super_block *sb, int type)
spin_lock(&dq_list_lock);
dqstats.syncs++;
spin_unlock(&dq_list_lock);
- up(&dqopt->dqonoff_sem);
+ mutex_unlock(&dqopt->dqonoff_mutex);
return 0;
}
@@ -515,7 +541,7 @@ static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
/*
* Put reference to dquot
* NOTE: If you change this function please check whether dqput_blocks() works right...
- * MUST be called with either dqptr_sem or dqonoff_sem held
+ * MUST be called with either dqptr_sem or dqonoff_mutex held
*/
static void dqput(struct dquot *dquot)
{
@@ -540,6 +566,10 @@ we_slept:
if (atomic_read(&dquot->dq_count) > 1) {
/* We have more than one user... nothing to do */
atomic_dec(&dquot->dq_count);
+ /* Releasing dquot during quotaoff phase? */
+ if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) &&
+ atomic_read(&dquot->dq_count) == 1)
+ wake_up(&dquot->dq_wait_unused);
spin_unlock(&dq_list_lock);
return;
}
@@ -576,11 +606,12 @@ static struct dquot *get_empty_dquot(struct super_block *sb, int type)
return NODQUOT;
memset((caddr_t)dquot, 0, sizeof(struct dquot));
- sema_init(&dquot->dq_lock, 1);
+ mutex_init(&dquot->dq_lock);
INIT_LIST_HEAD(&dquot->dq_free);
INIT_LIST_HEAD(&dquot->dq_inuse);
INIT_HLIST_NODE(&dquot->dq_hash);
INIT_LIST_HEAD(&dquot->dq_dirty);
+ init_waitqueue_head(&dquot->dq_wait_unused);
dquot->dq_sb = sb;
dquot->dq_type = type;
atomic_set(&dquot->dq_count, 1);
@@ -590,7 +621,7 @@ static struct dquot *get_empty_dquot(struct super_block *sb, int type)
/*
* Get reference to dquot
- * MUST be called with either dqptr_sem or dqonoff_sem held
+ * MUST be called with either dqptr_sem or dqonoff_mutex held
*/
static struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
{
@@ -656,7 +687,7 @@ static int dqinit_needed(struct inode *inode, int type)
return 0;
}
-/* This routine is guarded by dqonoff_sem semaphore */
+/* This routine is guarded by dqonoff_mutex mutex */
static void add_dquot_ref(struct super_block *sb, int type)
{
struct list_head *p;
@@ -732,13 +763,9 @@ static void drop_dquot_ref(struct super_block *sb, int type)
{
LIST_HEAD(tofree_head);
- /* We need to be guarded against prune_icache to reach all the
- * inodes - otherwise some can be on the local list of prune_icache */
- down(&iprune_sem);
down_write(&sb_dqopt(sb)->dqptr_sem);
remove_dquot_ref(sb, type, &tofree_head);
up_write(&sb_dqopt(sb)->dqptr_sem);
- up(&iprune_sem);
put_dquot_list(&tofree_head);
}
@@ -938,8 +965,8 @@ int dquot_initialize(struct inode *inode, int type)
unsigned int id = 0;
int cnt, ret = 0;
- /* First test before acquiring semaphore - solves deadlocks when we
- * re-enter the quota code and are already holding the semaphore */
+ /* First test before acquiring mutex - solves deadlocks when we
+ * re-enter the quota code and are already holding the mutex */
if (IS_NOQUOTA(inode))
return 0;
down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
@@ -1002,8 +1029,8 @@ int dquot_alloc_space(struct inode *inode, qsize_t number, int warn)
int cnt, ret = NO_QUOTA;
char warntype[MAXQUOTAS];
- /* First test before acquiring semaphore - solves deadlocks when we
- * re-enter the quota code and are already holding the semaphore */
+ /* First test before acquiring mutex - solves deadlocks when we
+ * re-enter the quota code and are already holding the mutex */
if (IS_NOQUOTA(inode)) {
out_add:
inode_add_bytes(inode, number);
@@ -1051,8 +1078,8 @@ int dquot_alloc_inode(const struct inode *inode, unsigned long number)
int cnt, ret = NO_QUOTA;
char warntype[MAXQUOTAS];
- /* First test before acquiring semaphore - solves deadlocks when we
- * re-enter the quota code and are already holding the semaphore */
+ /* First test before acquiring mutex - solves deadlocks when we
+ * re-enter the quota code and are already holding the mutex */
if (IS_NOQUOTA(inode))
return QUOTA_OK;
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
@@ -1095,8 +1122,8 @@ int dquot_free_space(struct inode *inode, qsize_t number)
{
unsigned int cnt;
- /* First test before acquiring semaphore - solves deadlocks when we
- * re-enter the quota code and are already holding the semaphore */
+ /* First test before acquiring mutex - solves deadlocks when we
+ * re-enter the quota code and are already holding the mutex */
if (IS_NOQUOTA(inode)) {
out_sub:
inode_sub_bytes(inode, number);
@@ -1131,8 +1158,8 @@ int dquot_free_inode(const struct inode *inode, unsigned long number)
{
unsigned int cnt;
- /* First test before acquiring semaphore - solves deadlocks when we
- * re-enter the quota code and are already holding the semaphore */
+ /* First test before acquiring mutex - solves deadlocks when we
+ * re-enter the quota code and are already holding the mutex */
if (IS_NOQUOTA(inode))
return QUOTA_OK;
down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
@@ -1171,8 +1198,8 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
char warntype[MAXQUOTAS];
- /* First test before acquiring semaphore - solves deadlocks when we
- * re-enter the quota code and are already holding the semaphore */
+ /* First test before acquiring mutex - solves deadlocks when we
+ * re-enter the quota code and are already holding the mutex */
if (IS_NOQUOTA(inode))
return QUOTA_OK;
/* Clear the arrays */
@@ -1266,9 +1293,9 @@ int dquot_commit_info(struct super_block *sb, int type)
int ret;
struct quota_info *dqopt = sb_dqopt(sb);
- down(&dqopt->dqio_sem);
+ mutex_lock(&dqopt->dqio_mutex);
ret = dqopt->ops[type]->write_file_info(sb, type);
- up(&dqopt->dqio_sem);
+ mutex_unlock(&dqopt->dqio_mutex);
return ret;
}
@@ -1324,7 +1351,7 @@ int vfs_quota_off(struct super_block *sb, int type)
struct inode *toputinode[MAXQUOTAS];
/* We need to serialize quota_off() for device */
- down(&dqopt->dqonoff_sem);
+ mutex_lock(&dqopt->dqonoff_mutex);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
toputinode[cnt] = NULL;
if (type != -1 && cnt != type)
@@ -1353,7 +1380,7 @@ int vfs_quota_off(struct super_block *sb, int type)
dqopt->info[cnt].dqi_bgrace = 0;
dqopt->ops[cnt] = NULL;
}
- up(&dqopt->dqonoff_sem);
+ mutex_unlock(&dqopt->dqonoff_mutex);
/* Sync the superblock so that buffers with quota data are written to
* disk (and so userspace sees correct data afterwards). */
if (sb->s_op->sync_fs)
@@ -1366,7 +1393,7 @@ int vfs_quota_off(struct super_block *sb, int type)
* changes done by userspace on the next quotaon() */
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
if (toputinode[cnt]) {
- down(&dqopt->dqonoff_sem);
+ mutex_lock(&dqopt->dqonoff_mutex);
/* If quota was reenabled in the meantime, we have
* nothing to do */
if (!sb_has_quota_enabled(sb, cnt)) {
@@ -1378,7 +1405,7 @@ int vfs_quota_off(struct super_block *sb, int type)
mark_inode_dirty(toputinode[cnt]);
iput(toputinode[cnt]);
}
- up(&dqopt->dqonoff_sem);
+ mutex_unlock(&dqopt->dqonoff_mutex);
}
if (sb->s_bdev)
invalidate_bdev(sb->s_bdev, 0);
@@ -1419,7 +1446,7 @@ static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
/* And now flush the block cache so that kernel sees the changes */
invalidate_bdev(sb->s_bdev, 0);
mutex_lock(&inode->i_mutex);
- down(&dqopt->dqonoff_sem);
+ mutex_lock(&dqopt->dqonoff_mutex);
if (sb_has_quota_enabled(sb, type)) {
error = -EBUSY;
goto out_lock;
@@ -1444,17 +1471,17 @@ static int vfs_quota_on_inode(struct inode *inode, int type, int format_id)
dqopt->ops[type] = fmt->qf_ops;
dqopt->info[type].dqi_format = fmt;
INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
- down(&dqopt->dqio_sem);
+ mutex_lock(&dqopt->dqio_mutex);
if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) {
- up(&dqopt->dqio_sem);
+ mutex_unlock(&dqopt->dqio_mutex);
goto out_file_init;
}
- up(&dqopt->dqio_sem);
+ mutex_unlock(&dqopt->dqio_mutex);
mutex_unlock(&inode->i_mutex);
set_enable_flags(dqopt, type);
add_dquot_ref(sb, type);
- up(&dqopt->dqonoff_sem);
+ mutex_unlock(&dqopt->dqonoff_mutex);
return 0;
@@ -1462,7 +1489,7 @@ out_file_init:
dqopt->files[type] = NULL;
iput(inode);
out_lock:
- up(&dqopt->dqonoff_sem);
+ mutex_unlock(&dqopt->dqonoff_mutex);
if (oldflags != -1) {
down_write(&dqopt->dqptr_sem);
/* Set the flags back (in the case of accidental quotaon()
@@ -1550,14 +1577,14 @@ int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *d
{
struct dquot *dquot;
- down(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
if (!(dquot = dqget(sb, id, type))) {
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return -ESRCH;
}
do_get_dqblk(dquot, di);
dqput(dquot);
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return 0;
}
@@ -1619,14 +1646,14 @@ int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *d
{
struct dquot *dquot;
- down(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
if (!(dquot = dqget(sb, id, type))) {
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return -ESRCH;
}
do_set_dqblk(dquot, di);
dqput(dquot);
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return 0;
}
@@ -1635,9 +1662,9 @@ int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
{
struct mem_dqinfo *mi;
- down(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
if (!sb_has_quota_enabled(sb, type)) {
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return -ESRCH;
}
mi = sb_dqopt(sb)->info + type;
@@ -1647,7 +1674,7 @@ int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
ii->dqi_flags = mi->dqi_flags & DQF_MASK;
ii->dqi_valid = IIF_ALL;
spin_unlock(&dq_data_lock);
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return 0;
}
@@ -1656,9 +1683,9 @@ int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
{
struct mem_dqinfo *mi;
- down(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
if (!sb_has_quota_enabled(sb, type)) {
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return -ESRCH;
}
mi = sb_dqopt(sb)->info + type;
@@ -1673,7 +1700,7 @@ int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii)
mark_info_dirty(sb, type);
/* Force write to disk */
sb->dq_op->write_info(sb, type);
- up(&sb_dqopt(sb)->dqonoff_sem);
+ mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
return 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-12 12:23:41 +0000