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authorAmir Goldstein <amir73il@gmail.com>2017-06-21 15:28:51 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2017-07-04 22:03:16 +0200
commita015dafcaf5b0316654a39bc598a76804595af90 (patch)
tree1a7e80fd1904519c9642b6549ad9f32bd5ab4d96
parent13c72075ac9f5a5cf3f61c85adaafffe48a6f797 (diff)
ovl: use ovl_inode mutex to synchronize concurrent copy up
Use the new ovl_inode mutex to synchonize concurrent copy up instead of the super block copy up workqueue. Moving the synchronization object from the overlay dentry to the overlay inode is needed for synchonizing concurrent copy up of lower hardlinks to the same upper inode. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
-rw-r--r--fs/overlayfs/ovl_entry.h5
-rw-r--r--fs/overlayfs/super.c3
-rw-r--r--fs/overlayfs/util.c23
3 files changed, 11 insertions, 20 deletions
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 50dfa4826152..d8f514a474ca 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -29,7 +29,6 @@ struct ovl_fs {
const struct cred *creator_cred;
bool tmpfile;
bool noxattr;
- wait_queue_head_t copyup_wq;
/* sb common to all layers */
struct super_block *same_sb;
};
@@ -41,7 +40,6 @@ struct ovl_entry {
struct {
u64 version;
bool opaque;
- bool copying;
};
struct rcu_head rcu;
};
@@ -57,6 +55,9 @@ struct ovl_inode {
struct inode vfs_inode;
struct dentry *__upperdentry;
struct inode *lower;
+
+ /* synchronize copy up and more */
+ struct mutex lock;
};
static inline struct ovl_inode *OVL_I(struct inode *inode)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 7c7b946b063f..b0d539af1fad 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -173,6 +173,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
oi->flags = 0;
oi->__upperdentry = NULL;
oi->lower = NULL;
+ mutex_init(&oi->lock);
return &oi->vfs_inode;
}
@@ -190,6 +191,7 @@ static void ovl_destroy_inode(struct inode *inode)
dput(oi->__upperdentry);
kfree(oi->redirect);
+ mutex_destroy(&oi->lock);
call_rcu(&inode->i_rcu, ovl_i_callback);
}
@@ -782,7 +784,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!ufs)
goto out;
- init_waitqueue_head(&ufs->copyup_wq);
ufs->config.redirect_dir = ovl_redirect_dir_def;
err = ovl_parse_opt((char *) data, &ufs->config);
if (err)
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 2fc4c22707aa..a0baaa7e224c 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -270,32 +270,21 @@ struct file *ovl_path_open(struct path *path, int flags)
int ovl_copy_up_start(struct dentry *dentry)
{
- struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- struct ovl_entry *oe = dentry->d_fsdata;
+ struct ovl_inode *oi = OVL_I(d_inode(dentry));
int err;
- spin_lock(&ofs->copyup_wq.lock);
- err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying);
- if (!err) {
- if (ovl_dentry_upper(dentry))
- err = 1; /* Already copied up */
- else
- oe->copying = true;
+ err = mutex_lock_interruptible(&oi->lock);
+ if (!err && ovl_dentry_upper(dentry)) {
+ err = 1; /* Already copied up */
+ mutex_unlock(&oi->lock);
}
- spin_unlock(&ofs->copyup_wq.lock);
return err;
}
void ovl_copy_up_end(struct dentry *dentry)
{
- struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
- struct ovl_entry *oe = dentry->d_fsdata;
-
- spin_lock(&ofs->copyup_wq.lock);
- oe->copying = false;
- wake_up_locked(&ofs->copyup_wq);
- spin_unlock(&ofs->copyup_wq.lock);
+ mutex_unlock(&OVL_I(d_inode(dentry))->lock);
}
bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)