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authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-22 00:36:41 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-22 00:36:41 +0400
commite2a0883e4071237d09b604a342c28b96b44a04b3 (patch)
treeaa56f4d376b5eb1c32358c19c2669c2a94e0e1fd /fs/fs_struct.c
parent3a990a52f9f25f45469e272017a31e7a3fda60ed (diff)
parent07c0c5d8b8c122b2f2df9ee574ac3083daefc981 (diff)
downloadlinux-e2a0883e4071237d09b604a342c28b96b44a04b3.tar.xz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...
Diffstat (limited to 'fs/fs_struct.c')
-rw-r--r--fs/fs_struct.c29
1 files changed, 15 insertions, 14 deletions
diff --git a/fs/fs_struct.c b/fs/fs_struct.c
index 78b519c13536..6324c4274959 100644
--- a/fs/fs_struct.c
+++ b/fs/fs_struct.c
@@ -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;
+ 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++;
- }
- if (fs->pwd.dentry == old_root->dentry
- && fs->pwd.mnt == old_root->mnt) {
path_get_longterm(new_root);
- fs->pwd = *new_root;
- count++;
}
- write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
}
task_unlock(p);
@@ -107,10 +110,8 @@ void exit_fs(struct task_struct *tsk)
int kill;
task_lock(tsk);
spin_lock(&fs->lock);
- write_seqcount_begin(&fs->seq);
tsk->fs = NULL;
kill = !--fs->users;
- write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
task_unlock(tsk);
if (kill)