提交 1ffe46d1 编写于 作者: E Eric W. Biederman 提交者: Al Viro

vfs: Merge check_submounts_and_drop and d_invalidate

Now that d_invalidate is the only caller of check_submounts_and_drop,
expand check_submounts_and_drop inline in d_invalidate.
Reviewed-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
上级 9b053f32
......@@ -645,32 +645,6 @@ void dput(struct dentry *dentry)
}
EXPORT_SYMBOL(dput);
/**
* d_invalidate - invalidate a dentry
* @dentry: dentry to invalidate
*
* Try to invalidate the dentry if it turns out to be
* possible. If there are reasons not to delete it
* return -EBUSY. On success return 0.
*
* no dcache lock.
*/
int d_invalidate(struct dentry * dentry)
{
/*
* If it's already been dropped, return OK.
*/
spin_lock(&dentry->d_lock);
if (d_unhashed(dentry)) {
spin_unlock(&dentry->d_lock);
return 0;
}
spin_unlock(&dentry->d_lock);
return check_submounts_and_drop(dentry);
}
EXPORT_SYMBOL(d_invalidate);
/* This must be called with d_lock held */
static inline void __dget_dlock(struct dentry *dentry)
......@@ -1190,7 +1164,7 @@ EXPORT_SYMBOL(have_submounts);
* reachable (e.g. NFS can unhash a directory dentry and then the complete
* subtree can become unreachable).
*
* Only one of check_submounts_and_drop() and d_set_mounted() must succeed. For
* Only one of d_invalidate() and d_set_mounted() must succeed. For
* this reason take rename_lock and d_lock on dentry and ancestors.
*/
int d_set_mounted(struct dentry *dentry)
......@@ -1199,7 +1173,7 @@ int d_set_mounted(struct dentry *dentry)
int ret = -ENOENT;
write_seqlock(&rename_lock);
for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) {
/* Need exclusion wrt. check_submounts_and_drop() */
/* Need exclusion wrt. d_invalidate() */
spin_lock(&p->d_lock);
if (unlikely(d_unhashed(p))) {
spin_unlock(&p->d_lock);
......@@ -1369,18 +1343,33 @@ static void check_and_drop(void *_data)
}
/**
* check_submounts_and_drop - detach submounts, prune dcache, and drop
* d_invalidate - detach submounts, prune dcache, and drop
* @dentry: dentry to invalidate (aka detach, prune and drop)
*
* Try to invalidate the dentry if it turns out to be
* possible. If there are reasons not to delete it
* return -EBUSY. On success return 0.
*
* no dcache lock.
*
* The final d_drop is done as an atomic operation relative to
* rename_lock ensuring there are no races with d_set_mounted. This
* ensures there are no unhashed dentries on the path to a mountpoint.
*
* @dentry: dentry to detach, prune and drop
*/
int check_submounts_and_drop(struct dentry *dentry)
int d_invalidate(struct dentry *dentry)
{
int ret = 0;
/*
* If it's already been dropped, return OK.
*/
spin_lock(&dentry->d_lock);
if (d_unhashed(dentry)) {
spin_unlock(&dentry->d_lock);
return 0;
}
spin_unlock(&dentry->d_lock);
/* Negative dentries can be dropped without further checks */
if (!dentry->d_inode) {
d_drop(dentry);
......@@ -1414,7 +1403,7 @@ int check_submounts_and_drop(struct dentry *dentry)
out:
return ret;
}
EXPORT_SYMBOL(check_submounts_and_drop);
EXPORT_SYMBOL(d_invalidate);
/**
* __d_alloc - allocate a dcache entry
......
......@@ -269,7 +269,6 @@ extern void d_prune_aliases(struct inode *);
/* test whether we have any submounts in a subdir tree */
extern int have_submounts(struct dentry *);
extern int check_submounts_and_drop(struct dentry *);
/*
* This adds the entry to the hash queues.
......
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