mirror of
https://github.com/torvalds/linux.git
synced 2024-12-26 04:42:12 +00:00
Merge branch 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache and mountpoint updates from Al Viro:
"Saner handling of refcounts to mountpoints.
Transfer the counting reference from struct mount ->mnt_mountpoint
over to struct mountpoint ->m_dentry. That allows us to get rid of the
convoluted games with ordering of mount shutdowns.
The cost is in teaching shrink_dcache_{parent,for_umount} to cope with
mixed-filesystem shrink lists, which we'll also need for the Slab
Movable Objects patchset"
* 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
switch the remnants of releasing the mountpoint away from fs_pin
get rid of detach_mnt()
make struct mountpoint bear the dentry reference to mountpoint, not struct mount
Teach shrink_dcache_parent() to cope with mixed-filesystem shrink lists
fs/namespace.c: shift put_mountpoint() to callers of unhash_mnt()
__detach_mounts(): lookup_mountpoint() can't return ERR_PTR() anymore
nfs: dget_parent() never returns NULL
ceph: don't open-code the check for dead lockref
This commit is contained in:
Linus Torvalds
commit
18253e034d
@ -1267,7 +1267,7 @@ __dentry_leases_walk(struct ceph_mds_client *mdsc,
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if (!spin_trylock(&dentry->d_lock))
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continue;
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if (dentry->d_lockref.count < 0) {
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if (__lockref_is_dead(&dentry->d_lockref)) {
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list_del_init(&di->lease_list);
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goto next;
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}
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100
fs/dcache.c
100
fs/dcache.c
@ -861,6 +861,32 @@ void dput(struct dentry *dentry)
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}
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EXPORT_SYMBOL(dput);
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static void __dput_to_list(struct dentry *dentry, struct list_head *list)
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__must_hold(&dentry->d_lock)
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{
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if (dentry->d_flags & DCACHE_SHRINK_LIST) {
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/* let the owner of the list it's on deal with it */
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--dentry->d_lockref.count;
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} else {
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if (dentry->d_flags & DCACHE_LRU_LIST)
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d_lru_del(dentry);
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if (!--dentry->d_lockref.count)
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d_shrink_add(dentry, list);
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}
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}
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void dput_to_list(struct dentry *dentry, struct list_head *list)
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{
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rcu_read_lock();
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if (likely(fast_dput(dentry))) {
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rcu_read_unlock();
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return;
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}
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rcu_read_unlock();
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if (!retain_dentry(dentry))
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__dput_to_list(dentry, list);
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spin_unlock(&dentry->d_lock);
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}
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/* This must be called with d_lock held */
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static inline void __dget_dlock(struct dentry *dentry)
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@ -1067,7 +1093,7 @@ out:
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return false;
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}
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static void shrink_dentry_list(struct list_head *list)
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void shrink_dentry_list(struct list_head *list)
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{
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while (!list_empty(list)) {
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struct dentry *dentry, *parent;
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@ -1089,18 +1115,9 @@ static void shrink_dentry_list(struct list_head *list)
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rcu_read_unlock();
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d_shrink_del(dentry);
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parent = dentry->d_parent;
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if (parent != dentry)
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__dput_to_list(parent, list);
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__dentry_kill(dentry);
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if (parent == dentry)
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continue;
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/*
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* We need to prune ancestors too. This is necessary to prevent
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* quadratic behavior of shrink_dcache_parent(), but is also
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* expected to be beneficial in reducing dentry cache
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* fragmentation.
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*/
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dentry = parent;
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while (dentry && !lockref_put_or_lock(&dentry->d_lockref))
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dentry = dentry_kill(dentry);
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}
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}
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@ -1445,8 +1462,11 @@ out:
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struct select_data {
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struct dentry *start;
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union {
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long found;
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struct dentry *victim;
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};
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struct list_head dispose;
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int found;
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};
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static enum d_walk_ret select_collect(void *_data, struct dentry *dentry)
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@ -1478,6 +1498,37 @@ out:
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return ret;
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}
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static enum d_walk_ret select_collect2(void *_data, struct dentry *dentry)
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{
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struct select_data *data = _data;
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enum d_walk_ret ret = D_WALK_CONTINUE;
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if (data->start == dentry)
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goto out;
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if (dentry->d_flags & DCACHE_SHRINK_LIST) {
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if (!dentry->d_lockref.count) {
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rcu_read_lock();
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data->victim = dentry;
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return D_WALK_QUIT;
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}
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} else {
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if (dentry->d_flags & DCACHE_LRU_LIST)
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d_lru_del(dentry);
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if (!dentry->d_lockref.count)
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d_shrink_add(dentry, &data->dispose);
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}
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/*
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* We can return to the caller if we have found some (this
|
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* ensures forward progress). We'll be coming back to find
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* the rest.
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*/
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if (!list_empty(&data->dispose))
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ret = need_resched() ? D_WALK_QUIT : D_WALK_NORETRY;
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out:
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return ret;
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}
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/**
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* shrink_dcache_parent - prune dcache
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* @parent: parent of entries to prune
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@ -1487,12 +1538,9 @@ out:
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void shrink_dcache_parent(struct dentry *parent)
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{
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for (;;) {
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struct select_data data;
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struct select_data data = {.start = parent};
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INIT_LIST_HEAD(&data.dispose);
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data.start = parent;
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data.found = 0;
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d_walk(parent, &data, select_collect);
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if (!list_empty(&data.dispose)) {
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@ -1503,6 +1551,24 @@ void shrink_dcache_parent(struct dentry *parent)
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cond_resched();
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if (!data.found)
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break;
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data.victim = NULL;
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d_walk(parent, &data, select_collect2);
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if (data.victim) {
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struct dentry *parent;
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spin_lock(&data.victim->d_lock);
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if (!shrink_lock_dentry(data.victim)) {
|
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spin_unlock(&data.victim->d_lock);
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rcu_read_unlock();
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} else {
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rcu_read_unlock();
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parent = data.victim->d_parent;
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if (parent != data.victim)
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__dput_to_list(parent, &data.dispose);
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__dentry_kill(data.victim);
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}
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}
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if (!list_empty(&data.dispose))
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shrink_dentry_list(&data.dispose);
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}
|
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}
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EXPORT_SYMBOL(shrink_dcache_parent);
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14
fs/fs_pin.c
14
fs/fs_pin.c
@ -19,18 +19,12 @@ void pin_remove(struct fs_pin *pin)
|
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spin_unlock_irq(&pin->wait.lock);
|
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}
|
||||
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||||
void pin_insert_group(struct fs_pin *pin, struct vfsmount *m, struct hlist_head *p)
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{
|
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spin_lock(&pin_lock);
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if (p)
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hlist_add_head(&pin->s_list, p);
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hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
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spin_unlock(&pin_lock);
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}
|
||||
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void pin_insert(struct fs_pin *pin, struct vfsmount *m)
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{
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pin_insert_group(pin, m, &m->mnt_sb->s_pins);
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spin_lock(&pin_lock);
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hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
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hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
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spin_unlock(&pin_lock);
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}
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void pin_kill(struct fs_pin *p)
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@ -157,6 +157,8 @@ extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
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extern struct dentry *d_alloc_cursor(struct dentry *);
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extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
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extern char *simple_dname(struct dentry *, char *, int);
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extern void dput_to_list(struct dentry *, struct list_head *);
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extern void shrink_dentry_list(struct list_head *);
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/*
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* read_write.c
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@ -58,7 +58,10 @@ struct mount {
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struct mount *mnt_master; /* slave is on master->mnt_slave_list */
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struct mnt_namespace *mnt_ns; /* containing namespace */
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struct mountpoint *mnt_mp; /* where is it mounted */
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struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
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union {
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struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
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struct hlist_node mnt_umount;
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};
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struct list_head mnt_umounting; /* list entry for umount propagation */
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#ifdef CONFIG_FSNOTIFY
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struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
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@ -68,8 +71,7 @@ struct mount {
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int mnt_group_id; /* peer group identifier */
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int mnt_expiry_mark; /* true if marked for expiry */
|
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struct hlist_head mnt_pins;
|
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struct fs_pin mnt_umount;
|
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struct dentry *mnt_ex_mountpoint;
|
||||
struct hlist_head mnt_stuck_children;
|
||||
} __randomize_layout;
|
||||
|
||||
#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
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|
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159
fs/namespace.c
159
fs/namespace.c
@ -70,6 +70,8 @@ static struct hlist_head *mount_hashtable __read_mostly;
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static struct hlist_head *mountpoint_hashtable __read_mostly;
|
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static struct kmem_cache *mnt_cache __read_mostly;
|
||||
static DECLARE_RWSEM(namespace_sem);
|
||||
static HLIST_HEAD(unmounted); /* protected by namespace_sem */
|
||||
static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */
|
||||
|
||||
/* /sys/fs */
|
||||
struct kobject *fs_kobj;
|
||||
@ -170,14 +172,6 @@ unsigned int mnt_get_count(struct mount *mnt)
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#endif
|
||||
}
|
||||
|
||||
static void drop_mountpoint(struct fs_pin *p)
|
||||
{
|
||||
struct mount *m = container_of(p, struct mount, mnt_umount);
|
||||
dput(m->mnt_ex_mountpoint);
|
||||
pin_remove(p);
|
||||
mntput(&m->mnt);
|
||||
}
|
||||
|
||||
static struct mount *alloc_vfsmnt(const char *name)
|
||||
{
|
||||
struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
|
||||
@ -215,7 +209,7 @@ static struct mount *alloc_vfsmnt(const char *name)
|
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INIT_LIST_HEAD(&mnt->mnt_slave);
|
||||
INIT_HLIST_NODE(&mnt->mnt_mp_list);
|
||||
INIT_LIST_HEAD(&mnt->mnt_umounting);
|
||||
init_fs_pin(&mnt->mnt_umount, drop_mountpoint);
|
||||
INIT_HLIST_HEAD(&mnt->mnt_stuck_children);
|
||||
}
|
||||
return mnt;
|
||||
|
||||
@ -740,7 +734,7 @@ mountpoint:
|
||||
|
||||
/* Add the new mountpoint to the hash table */
|
||||
read_seqlock_excl(&mount_lock);
|
||||
new->m_dentry = dentry;
|
||||
new->m_dentry = dget(dentry);
|
||||
new->m_count = 1;
|
||||
hlist_add_head(&new->m_hash, mp_hash(dentry));
|
||||
INIT_HLIST_HEAD(&new->m_list);
|
||||
@ -753,7 +747,11 @@ done:
|
||||
return mp;
|
||||
}
|
||||
|
||||
static void put_mountpoint(struct mountpoint *mp)
|
||||
/*
|
||||
* vfsmount lock must be held. Additionally, the caller is responsible
|
||||
* for serializing calls for given disposal list.
|
||||
*/
|
||||
static void __put_mountpoint(struct mountpoint *mp, struct list_head *list)
|
||||
{
|
||||
if (!--mp->m_count) {
|
||||
struct dentry *dentry = mp->m_dentry;
|
||||
@ -761,11 +759,18 @@ static void put_mountpoint(struct mountpoint *mp)
|
||||
spin_lock(&dentry->d_lock);
|
||||
dentry->d_flags &= ~DCACHE_MOUNTED;
|
||||
spin_unlock(&dentry->d_lock);
|
||||
dput_to_list(dentry, list);
|
||||
hlist_del(&mp->m_hash);
|
||||
kfree(mp);
|
||||
}
|
||||
}
|
||||
|
||||
/* called with namespace_lock and vfsmount lock */
|
||||
static void put_mountpoint(struct mountpoint *mp)
|
||||
{
|
||||
__put_mountpoint(mp, &ex_mountpoints);
|
||||
}
|
||||
|
||||
static inline int check_mnt(struct mount *mnt)
|
||||
{
|
||||
return mnt->mnt_ns == current->nsproxy->mnt_ns;
|
||||
@ -796,25 +801,17 @@ static void __touch_mnt_namespace(struct mnt_namespace *ns)
|
||||
/*
|
||||
* vfsmount lock must be held for write
|
||||
*/
|
||||
static void unhash_mnt(struct mount *mnt)
|
||||
static struct mountpoint *unhash_mnt(struct mount *mnt)
|
||||
{
|
||||
struct mountpoint *mp;
|
||||
mnt->mnt_parent = mnt;
|
||||
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
|
||||
list_del_init(&mnt->mnt_child);
|
||||
hlist_del_init_rcu(&mnt->mnt_hash);
|
||||
hlist_del_init(&mnt->mnt_mp_list);
|
||||
put_mountpoint(mnt->mnt_mp);
|
||||
mp = mnt->mnt_mp;
|
||||
mnt->mnt_mp = NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* vfsmount lock must be held for write
|
||||
*/
|
||||
static void detach_mnt(struct mount *mnt, struct path *old_path)
|
||||
{
|
||||
old_path->dentry = mnt->mnt_mountpoint;
|
||||
old_path->mnt = &mnt->mnt_parent->mnt;
|
||||
unhash_mnt(mnt);
|
||||
return mp;
|
||||
}
|
||||
|
||||
/*
|
||||
@ -822,9 +819,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path)
|
||||
*/
|
||||
static void umount_mnt(struct mount *mnt)
|
||||
{
|
||||
/* old mountpoint will be dropped when we can do that */
|
||||
mnt->mnt_ex_mountpoint = mnt->mnt_mountpoint;
|
||||
unhash_mnt(mnt);
|
||||
put_mountpoint(unhash_mnt(mnt));
|
||||
}
|
||||
|
||||
/*
|
||||
@ -836,7 +831,7 @@ void mnt_set_mountpoint(struct mount *mnt,
|
||||
{
|
||||
mp->m_count++;
|
||||
mnt_add_count(mnt, 1); /* essentially, that's mntget */
|
||||
child_mnt->mnt_mountpoint = dget(mp->m_dentry);
|
||||
child_mnt->mnt_mountpoint = mp->m_dentry;
|
||||
child_mnt->mnt_parent = mnt;
|
||||
child_mnt->mnt_mp = mp;
|
||||
hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
|
||||
@ -863,7 +858,6 @@ static void attach_mnt(struct mount *mnt,
|
||||
void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *mnt)
|
||||
{
|
||||
struct mountpoint *old_mp = mnt->mnt_mp;
|
||||
struct dentry *old_mountpoint = mnt->mnt_mountpoint;
|
||||
struct mount *old_parent = mnt->mnt_parent;
|
||||
|
||||
list_del_init(&mnt->mnt_child);
|
||||
@ -873,22 +867,6 @@ void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct m
|
||||
attach_mnt(mnt, parent, mp);
|
||||
|
||||
put_mountpoint(old_mp);
|
||||
|
||||
/*
|
||||
* Safely avoid even the suggestion this code might sleep or
|
||||
* lock the mount hash by taking advantage of the knowledge that
|
||||
* mnt_change_mountpoint will not release the final reference
|
||||
* to a mountpoint.
|
||||
*
|
||||
* During mounting, the mount passed in as the parent mount will
|
||||
* continue to use the old mountpoint and during unmounting, the
|
||||
* old mountpoint will continue to exist until namespace_unlock,
|
||||
* which happens well after mnt_change_mountpoint.
|
||||
*/
|
||||
spin_lock(&old_mountpoint->d_lock);
|
||||
old_mountpoint->d_lockref.count--;
|
||||
spin_unlock(&old_mountpoint->d_lock);
|
||||
|
||||
mnt_add_count(old_parent, -1);
|
||||
}
|
||||
|
||||
@ -1103,19 +1081,22 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
|
||||
|
||||
static void cleanup_mnt(struct mount *mnt)
|
||||
{
|
||||
struct hlist_node *p;
|
||||
struct mount *m;
|
||||
/*
|
||||
* This probably indicates that somebody messed
|
||||
* up a mnt_want/drop_write() pair. If this
|
||||
* happens, the filesystem was probably unable
|
||||
* to make r/w->r/o transitions.
|
||||
*/
|
||||
/*
|
||||
* The warning here probably indicates that somebody messed
|
||||
* up a mnt_want/drop_write() pair. If this happens, the
|
||||
* filesystem was probably unable to make r/w->r/o transitions.
|
||||
* The locking used to deal with mnt_count decrement provides barriers,
|
||||
* so mnt_get_writers() below is safe.
|
||||
*/
|
||||
WARN_ON(mnt_get_writers(mnt));
|
||||
if (unlikely(mnt->mnt_pins.first))
|
||||
mnt_pin_kill(mnt);
|
||||
hlist_for_each_entry_safe(m, p, &mnt->mnt_stuck_children, mnt_umount) {
|
||||
hlist_del(&m->mnt_umount);
|
||||
mntput(&m->mnt);
|
||||
}
|
||||
fsnotify_vfsmount_delete(&mnt->mnt);
|
||||
dput(mnt->mnt.mnt_root);
|
||||
deactivate_super(mnt->mnt.mnt_sb);
|
||||
@ -1141,6 +1122,8 @@ static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput);
|
||||
|
||||
static void mntput_no_expire(struct mount *mnt)
|
||||
{
|
||||
LIST_HEAD(list);
|
||||
|
||||
rcu_read_lock();
|
||||
if (likely(READ_ONCE(mnt->mnt_ns))) {
|
||||
/*
|
||||
@ -1181,10 +1164,12 @@ static void mntput_no_expire(struct mount *mnt)
|
||||
if (unlikely(!list_empty(&mnt->mnt_mounts))) {
|
||||
struct mount *p, *tmp;
|
||||
list_for_each_entry_safe(p, tmp, &mnt->mnt_mounts, mnt_child) {
|
||||
umount_mnt(p);
|
||||
__put_mountpoint(unhash_mnt(p), &list);
|
||||
hlist_add_head(&p->mnt_umount, &mnt->mnt_stuck_children);
|
||||
}
|
||||
}
|
||||
unlock_mount_hash();
|
||||
shrink_dentry_list(&list);
|
||||
|
||||
if (likely(!(mnt->mnt.mnt_flags & MNT_INTERNAL))) {
|
||||
struct task_struct *task = current;
|
||||
@ -1370,22 +1355,29 @@ int may_umount(struct vfsmount *mnt)
|
||||
|
||||
EXPORT_SYMBOL(may_umount);
|
||||
|
||||
static HLIST_HEAD(unmounted); /* protected by namespace_sem */
|
||||
|
||||
static void namespace_unlock(void)
|
||||
{
|
||||
struct hlist_head head;
|
||||
struct hlist_node *p;
|
||||
struct mount *m;
|
||||
LIST_HEAD(list);
|
||||
|
||||
hlist_move_list(&unmounted, &head);
|
||||
list_splice_init(&ex_mountpoints, &list);
|
||||
|
||||
up_write(&namespace_sem);
|
||||
|
||||
shrink_dentry_list(&list);
|
||||
|
||||
if (likely(hlist_empty(&head)))
|
||||
return;
|
||||
|
||||
synchronize_rcu_expedited();
|
||||
|
||||
group_pin_kill(&head);
|
||||
hlist_for_each_entry_safe(m, p, &head, mnt_umount) {
|
||||
hlist_del(&m->mnt_umount);
|
||||
mntput(&m->mnt);
|
||||
}
|
||||
}
|
||||
|
||||
static inline void namespace_lock(void)
|
||||
@ -1472,8 +1464,6 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
|
||||
|
||||
disconnect = disconnect_mount(p, how);
|
||||
|
||||
pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt,
|
||||
disconnect ? &unmounted : NULL);
|
||||
if (mnt_has_parent(p)) {
|
||||
mnt_add_count(p->mnt_parent, -1);
|
||||
if (!disconnect) {
|
||||
@ -1481,6 +1471,7 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
|
||||
list_add_tail(&p->mnt_child, &p->mnt_parent->mnt_mounts);
|
||||
} else {
|
||||
umount_mnt(p);
|
||||
hlist_add_head(&p->mnt_umount, &unmounted);
|
||||
}
|
||||
}
|
||||
change_mnt_propagation(p, MS_PRIVATE);
|
||||
@ -1626,15 +1617,15 @@ void __detach_mounts(struct dentry *dentry)
|
||||
namespace_lock();
|
||||
lock_mount_hash();
|
||||
mp = lookup_mountpoint(dentry);
|
||||
if (IS_ERR_OR_NULL(mp))
|
||||
if (!mp)
|
||||
goto out_unlock;
|
||||
|
||||
event++;
|
||||
while (!hlist_empty(&mp->m_list)) {
|
||||
mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);
|
||||
if (mnt->mnt.mnt_flags & MNT_UMOUNT) {
|
||||
hlist_add_head(&mnt->mnt_umount.s_list, &unmounted);
|
||||
umount_mnt(mnt);
|
||||
hlist_add_head(&mnt->mnt_umount, &unmounted);
|
||||
}
|
||||
else umount_tree(mnt, UMOUNT_CONNECTED);
|
||||
}
|
||||
@ -2046,7 +2037,7 @@ int count_mounts(struct mnt_namespace *ns, struct mount *mnt)
|
||||
static int attach_recursive_mnt(struct mount *source_mnt,
|
||||
struct mount *dest_mnt,
|
||||
struct mountpoint *dest_mp,
|
||||
struct path *parent_path)
|
||||
bool moving)
|
||||
{
|
||||
struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
|
||||
HLIST_HEAD(tree_list);
|
||||
@ -2064,7 +2055,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
|
||||
return PTR_ERR(smp);
|
||||
|
||||
/* Is there space to add these mounts to the mount namespace? */
|
||||
if (!parent_path) {
|
||||
if (!moving) {
|
||||
err = count_mounts(ns, source_mnt);
|
||||
if (err)
|
||||
goto out;
|
||||
@ -2083,8 +2074,8 @@ static int attach_recursive_mnt(struct mount *source_mnt,
|
||||
} else {
|
||||
lock_mount_hash();
|
||||
}
|
||||
if (parent_path) {
|
||||
detach_mnt(source_mnt, parent_path);
|
||||
if (moving) {
|
||||
unhash_mnt(source_mnt);
|
||||
attach_mnt(source_mnt, dest_mnt, dest_mp);
|
||||
touch_mnt_namespace(source_mnt->mnt_ns);
|
||||
} else {
|
||||
@ -2182,7 +2173,7 @@ static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp)
|
||||
d_is_dir(mnt->mnt.mnt_root))
|
||||
return -ENOTDIR;
|
||||
|
||||
return attach_recursive_mnt(mnt, p, mp, NULL);
|
||||
return attach_recursive_mnt(mnt, p, mp, false);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -2575,11 +2566,11 @@ out:
|
||||
|
||||
static int do_move_mount(struct path *old_path, struct path *new_path)
|
||||
{
|
||||
struct path parent_path = {.mnt = NULL, .dentry = NULL};
|
||||
struct mnt_namespace *ns;
|
||||
struct mount *p;
|
||||
struct mount *old;
|
||||
struct mountpoint *mp;
|
||||
struct mount *parent;
|
||||
struct mountpoint *mp, *old_mp;
|
||||
int err;
|
||||
bool attached;
|
||||
|
||||
@ -2589,7 +2580,9 @@ static int do_move_mount(struct path *old_path, struct path *new_path)
|
||||
|
||||
old = real_mount(old_path->mnt);
|
||||
p = real_mount(new_path->mnt);
|
||||
parent = old->mnt_parent;
|
||||
attached = mnt_has_parent(old);
|
||||
old_mp = old->mnt_mp;
|
||||
ns = old->mnt_ns;
|
||||
|
||||
err = -EINVAL;
|
||||
@ -2617,7 +2610,7 @@ static int do_move_mount(struct path *old_path, struct path *new_path)
|
||||
/*
|
||||
* Don't move a mount residing in a shared parent.
|
||||
*/
|
||||
if (attached && IS_MNT_SHARED(old->mnt_parent))
|
||||
if (attached && IS_MNT_SHARED(parent))
|
||||
goto out;
|
||||
/*
|
||||
* Don't move a mount tree containing unbindable mounts to a destination
|
||||
@ -2633,18 +2626,21 @@ static int do_move_mount(struct path *old_path, struct path *new_path)
|
||||
goto out;
|
||||
|
||||
err = attach_recursive_mnt(old, real_mount(new_path->mnt), mp,
|
||||
attached ? &parent_path : NULL);
|
||||
attached);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
/* if the mount is moved, it should no longer be expire
|
||||
* automatically */
|
||||
list_del_init(&old->mnt_expire);
|
||||
if (attached)
|
||||
put_mountpoint(old_mp);
|
||||
out:
|
||||
unlock_mount(mp);
|
||||
if (!err) {
|
||||
path_put(&parent_path);
|
||||
if (!attached)
|
||||
if (attached)
|
||||
mntput_no_expire(parent);
|
||||
else
|
||||
free_mnt_ns(ns);
|
||||
}
|
||||
return err;
|
||||
@ -3589,8 +3585,8 @@ EXPORT_SYMBOL(path_is_under);
|
||||
SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
|
||||
const char __user *, put_old)
|
||||
{
|
||||
struct path new, old, parent_path, root_parent, root;
|
||||
struct mount *new_mnt, *root_mnt, *old_mnt;
|
||||
struct path new, old, root;
|
||||
struct mount *new_mnt, *root_mnt, *old_mnt, *root_parent, *ex_parent;
|
||||
struct mountpoint *old_mp, *root_mp;
|
||||
int error;
|
||||
|
||||
@ -3619,9 +3615,11 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
|
||||
new_mnt = real_mount(new.mnt);
|
||||
root_mnt = real_mount(root.mnt);
|
||||
old_mnt = real_mount(old.mnt);
|
||||
ex_parent = new_mnt->mnt_parent;
|
||||
root_parent = root_mnt->mnt_parent;
|
||||
if (IS_MNT_SHARED(old_mnt) ||
|
||||
IS_MNT_SHARED(new_mnt->mnt_parent) ||
|
||||
IS_MNT_SHARED(root_mnt->mnt_parent))
|
||||
IS_MNT_SHARED(ex_parent) ||
|
||||
IS_MNT_SHARED(root_parent))
|
||||
goto out4;
|
||||
if (!check_mnt(root_mnt) || !check_mnt(new_mnt))
|
||||
goto out4;
|
||||
@ -3638,7 +3636,6 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
|
||||
goto out4; /* not a mountpoint */
|
||||
if (!mnt_has_parent(root_mnt))
|
||||
goto out4; /* not attached */
|
||||
root_mp = root_mnt->mnt_mp;
|
||||
if (new.mnt->mnt_root != new.dentry)
|
||||
goto out4; /* not a mountpoint */
|
||||
if (!mnt_has_parent(new_mnt))
|
||||
@ -3649,10 +3646,9 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
|
||||
/* make certain new is below the root */
|
||||
if (!is_path_reachable(new_mnt, new.dentry, &root))
|
||||
goto out4;
|
||||
root_mp->m_count++; /* pin it so it won't go away */
|
||||
lock_mount_hash();
|
||||
detach_mnt(new_mnt, &parent_path);
|
||||
detach_mnt(root_mnt, &root_parent);
|
||||
umount_mnt(new_mnt);
|
||||
root_mp = unhash_mnt(root_mnt); /* we'll need its mountpoint */
|
||||
if (root_mnt->mnt.mnt_flags & MNT_LOCKED) {
|
||||
new_mnt->mnt.mnt_flags |= MNT_LOCKED;
|
||||
root_mnt->mnt.mnt_flags &= ~MNT_LOCKED;
|
||||
@ -3660,7 +3656,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
|
||||
/* mount old root on put_old */
|
||||
attach_mnt(root_mnt, old_mnt, old_mp);
|
||||
/* mount new_root on / */
|
||||
attach_mnt(new_mnt, real_mount(root_parent.mnt), root_mp);
|
||||
attach_mnt(new_mnt, root_parent, root_mp);
|
||||
mnt_add_count(root_parent, -1);
|
||||
touch_mnt_namespace(current->nsproxy->mnt_ns);
|
||||
/* A moved mount should not expire automatically */
|
||||
list_del_init(&new_mnt->mnt_expire);
|
||||
@ -3670,10 +3667,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
|
||||
error = 0;
|
||||
out4:
|
||||
unlock_mount(old_mp);
|
||||
if (!error) {
|
||||
path_put(&root_parent);
|
||||
path_put(&parent_path);
|
||||
}
|
||||
if (!error)
|
||||
mntput_no_expire(ex_parent);
|
||||
out3:
|
||||
path_put(&root);
|
||||
out2:
|
||||
|
||||
@ -457,10 +457,8 @@ int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
|
||||
struct dentry *pd_dentry;
|
||||
|
||||
pd_dentry = dget_parent(dentry);
|
||||
if (pd_dentry != NULL) {
|
||||
nfs_zap_caches(d_inode(pd_dentry));
|
||||
dput(pd_dentry);
|
||||
}
|
||||
nfs_zap_caches(d_inode(pd_dentry));
|
||||
dput(pd_dentry);
|
||||
}
|
||||
nfs_free_fattr(res.fattr);
|
||||
if (error < 0)
|
||||
|
||||
@ -20,6 +20,5 @@ static inline void init_fs_pin(struct fs_pin *p, void (*kill)(struct fs_pin *))
|
||||
}
|
||||
|
||||
void pin_remove(struct fs_pin *);
|
||||
void pin_insert_group(struct fs_pin *, struct vfsmount *, struct hlist_head *);
|
||||
void pin_insert(struct fs_pin *, struct vfsmount *);
|
||||
void pin_kill(struct fs_pin *);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user