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vfs: take path_get_longterm() out of write_seqcount scope

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-03-15 14:48:55 -04:00
parent 3ee05ed067
commit 82234e61a8
1 changed files with 17 additions and 14 deletions
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31
fs/fs_struct.c
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@ -26,11 +26,11 @@ void set_fs_root(struct fs_struct *fs, struct path *path)
{
struct path old_root;
path_get_longterm(path);
spin_lock(&fs->lock);
write_seqcount_begin(&fs->seq);
old_root = fs->root;
fs->root = *path;
path_get_longterm(path);
write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_root.dentry)
@ -45,11 +45,11 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path)
{
struct path old_pwd;
path_get_longterm(path);
spin_lock(&fs->lock);
write_seqcount_begin(&fs->seq);
old_pwd = fs->pwd;
fs->pwd = *path;
path_get_longterm(path);
write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
@ -57,6 +57,14 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path)
path_put_longterm(&old_pwd);
}
static inline int replace_path(struct path *p, const struct path *old, const struct path *new)
{
if (likely(p->dentry != old->dentry || p->mnt != old->mnt))
return 0;
*p = *new;
return 1;
}
void chroot_fs_refs(struct path *old_root, struct path *new_root)
{
struct task_struct *g, *p;
@ -68,21 +76,16 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root)
task_lock(p);
fs = p->fs;
if (fs) {
int hits = 0;
spin_lock(&fs->lock);
write_seqcount_begin(&fs->seq);
if (fs->root.dentry == old_root->dentry
&& fs->root.mnt == old_root->mnt) {
path_get_longterm(new_root);
fs->root = *new_root;
count++;
}
if (fs->pwd.dentry == old_root->dentry
&& fs->pwd.mnt == old_root->mnt) {
path_get_longterm(new_root);
fs->pwd = *new_root;
count++;
}
hits += replace_path(&fs->root, old_root, new_root);
hits += replace_path(&fs->pwd, old_root, new_root);
write_seqcount_end(&fs->seq);
while (hits--) {
count++;
path_get_longterm(new_root);
}
spin_unlock(&fs->lock);
}
task_unlock(p);