@@ -856,6 +856,10 @@ static int ceph_mknod(struct user_namespace *mnt_userns, struct inode *dir,
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
+ err = ceph_wait_on_conflict_unlink(dentry);
+ if (err)
+ return err;
+
if (ceph_quota_is_max_files_exceeded(dir)) {
err = -EDQUOT;
goto out;
@@ -918,6 +922,10 @@ static int ceph_symlink(struct user_namespace *mnt_userns, struct inode *dir,
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
+ err = ceph_wait_on_conflict_unlink(dentry);
+ if (err)
+ return err;
+
if (ceph_quota_is_max_files_exceeded(dir)) {
err = -EDQUOT;
goto out;
@@ -968,9 +976,13 @@ static int ceph_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
- int err = -EROFS;
+ int err;
int op;
+ err = ceph_wait_on_conflict_unlink(dentry);
+ if (err)
+ return err;
+
if (ceph_snap(dir) == CEPH_SNAPDIR) {
/* mkdir .snap/foo is a MKSNAP */
op = CEPH_MDS_OP_MKSNAP;
@@ -980,6 +992,7 @@ static int ceph_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
op = CEPH_MDS_OP_MKDIR;
} else {
+ err = -EROFS;
goto out;
}
@@ -1037,6 +1050,10 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
struct ceph_mds_request *req;
int err;
+ err = ceph_wait_on_conflict_unlink(dentry);
+ if (err)
+ return err;
+
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
@@ -1071,9 +1088,27 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
+ struct dentry *dentry = req->r_dentry;
+ struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
+ struct ceph_dentry_info *di = ceph_dentry(dentry);
int result = req->r_err ? req->r_err :
le32_to_cpu(req->r_reply_info.head->result);
+ if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
+ pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
+ __func__, dentry, dentry);
+
+ spin_lock(&fsc->async_unlink_conflict_lock);
+ hash_del_rcu(&di->hnode);
+ spin_unlock(&fsc->async_unlink_conflict_lock);
+
+ spin_lock(&dentry->d_lock);
+ di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
+ wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT);
+ spin_unlock(&dentry->d_lock);
+
+ synchronize_rcu();
+
if (result == -EJUKEBOX)
goto out;
@@ -1081,7 +1116,7 @@ static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
if (result) {
int pathlen = 0;
u64 base = 0;
- char *path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
+ char *path = ceph_mdsc_build_path(dentry, &pathlen,
&base, 0);
/* mark error on parent + clear complete */
@@ -1089,13 +1124,13 @@ static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
ceph_dir_clear_complete(req->r_parent);
/* drop the dentry -- we don't know its status */
- if (!d_unhashed(req->r_dentry))
- d_drop(req->r_dentry);
+ if (!d_unhashed(dentry))
+ d_drop(dentry);
/* mark inode itself for an error (since metadata is bogus) */
mapping_set_error(req->r_old_inode->i_mapping, result);
- pr_warn("ceph: async unlink failure path=(%llx)%s result=%d!\n",
+ pr_warn("async unlink failure path=(%llx)%s result=%d!\n",
base, IS_ERR(path) ? "<<bad>>" : path, result);
ceph_mdsc_free_path(path, pathlen);
}
@@ -1180,6 +1215,8 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
if (try_async && op == CEPH_MDS_OP_UNLINK &&
(req->r_dir_caps = get_caps_for_async_unlink(dir, dentry))) {
+ struct ceph_dentry_info *di = ceph_dentry(dentry);
+
dout("async unlink on %llu/%.*s caps=%s", ceph_ino(dir),
dentry->d_name.len, dentry->d_name.name,
ceph_cap_string(req->r_dir_caps));
@@ -1187,6 +1224,16 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
req->r_callback = ceph_async_unlink_cb;
req->r_old_inode = d_inode(dentry);
ihold(req->r_old_inode);
+
+ spin_lock(&dentry->d_lock);
+ di->flags |= CEPH_DENTRY_ASYNC_UNLINK;
+ spin_unlock(&dentry->d_lock);
+
+ spin_lock(&fsc->async_unlink_conflict_lock);
+ hash_add_rcu(fsc->async_unlink_conflict, &di->hnode,
+ dentry->d_name.hash);
+ spin_unlock(&fsc->async_unlink_conflict_lock);
+
err = ceph_mdsc_submit_request(mdsc, dir, req);
if (!err) {
/*
@@ -1195,10 +1242,20 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
*/
drop_nlink(inode);
d_delete(dentry);
- } else if (err == -EJUKEBOX) {
- try_async = false;
- ceph_mdsc_put_request(req);
- goto retry;
+ } else {
+ spin_lock(&fsc->async_unlink_conflict_lock);
+ hash_del_rcu(&di->hnode);
+ spin_unlock(&fsc->async_unlink_conflict_lock);
+
+ spin_lock(&dentry->d_lock);
+ di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
+ spin_unlock(&dentry->d_lock);
+
+ if (err == -EJUKEBOX) {
+ try_async = false;
+ ceph_mdsc_put_request(req);
+ goto retry;
+ }
}
} else {
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
@@ -1237,6 +1294,10 @@ static int ceph_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
(!ceph_quota_is_same_realm(old_dir, new_dir)))
return -EXDEV;
+ err = ceph_wait_on_conflict_unlink(new_dentry);
+ if (err)
+ return err;
+
dout("rename dir %p dentry %p to dir %p dentry %p\n",
old_dir, old_dentry, new_dir, new_dentry);
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
@@ -569,7 +569,7 @@ static void ceph_async_create_cb(struct ceph_mds_client *mdsc,
char *path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
&base, 0);
- pr_warn("ceph: async create failure path=(%llx)%s result=%d!\n",
+ pr_warn("async create failure path=(%llx)%s result=%d!\n",
base, IS_ERR(path) ? "<<bad>>" : path, result);
ceph_mdsc_free_path(path, pathlen);
@@ -740,6 +740,10 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
if (dentry->d_name.len > NAME_MAX)
return -ENAMETOOLONG;
+ err = ceph_wait_on_conflict_unlink(dentry);
+ if (err)
+ return err;
+
if (flags & O_CREAT) {
if (ceph_quota_is_max_files_exceeded(dir))
return -EDQUOT;
@@ -456,7 +456,7 @@ static int ceph_parse_deleg_inos(void **p, void *end,
dout("added delegated inode 0x%llx\n",
start - 1);
} else if (err == -EBUSY) {
- pr_warn("ceph: MDS delegated inode 0x%llx more than once.\n",
+ pr_warn("MDS delegated inode 0x%llx more than once.\n",
start - 1);
} else {
return err;
@@ -655,6 +655,79 @@ static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
}
+/*
+ * In async unlink case the kclient won't wait for the first reply
+ * from MDS and just drop all the links and unhash the dentry and then
+ * succeeds immediately.
+ *
+ * For any new create/link/rename,etc requests followed by using the
+ * same file names we must wait for the first reply of the inflight
+ * unlink request, or the MDS possibly will fail these following
+ * requests with -EEXIST if the inflight async unlink request was
+ * delayed for some reasons.
+ *
+ * And the worst case is that for the none async openc request it will
+ * successfully open the file if the CDentry hasn't been unlinked yet,
+ * but later the previous delayed async unlink request will remove the
+ * CDenty. That means the just created file is possiblly deleted later
+ * by accident.
+ *
+ * We need to wait for the inflight async unlink requests to finish
+ * when creating new files/directories by using the same file names.
+ */
+int ceph_wait_on_conflict_unlink(struct dentry *dentry)
+{
+ struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
+ struct dentry *pdentry = dentry->d_parent;
+ struct dentry *udentry, *found = NULL;
+ struct ceph_dentry_info *di;
+ struct qstr dname;
+ u32 hash = dentry->d_name.hash;
+ int err;
+
+ dname.name = dentry->d_name.name;
+ dname.len = dentry->d_name.len;
+
+ rcu_read_lock();
+ hash_for_each_possible_rcu(fsc->async_unlink_conflict, di,
+ hnode, hash) {
+ udentry = di->dentry;
+
+ spin_lock(&udentry->d_lock);
+ if (udentry->d_name.hash != hash)
+ goto next;
+ if (unlikely(udentry->d_parent != pdentry))
+ goto next;
+ if (!hash_hashed(&di->hnode))
+ goto next;
+
+ if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
+ pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
+ __func__, dentry, dentry);
+
+ if (!d_same_name(udentry, pdentry, &dname))
+ goto next;
+
+ spin_unlock(&udentry->d_lock);
+ found = dget(udentry);
+ break;
+next:
+ spin_unlock(&udentry->d_lock);
+ }
+ rcu_read_unlock();
+
+ if (likely(!found))
+ return 0;
+
+ dout("%s dentry %p:%pd conflict with old %p:%pd\n", __func__,
+ dentry, dentry, found, found);
+
+ err = wait_on_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT,
+ TASK_KILLABLE);
+ dput(found);
+ return err;
+}
+
/*
* sessions
@@ -576,6 +576,7 @@ static inline int ceph_wait_on_async_create(struct inode *inode)
TASK_KILLABLE);
}
+extern int ceph_wait_on_conflict_unlink(struct dentry *dentry);
extern u64 ceph_get_deleg_ino(struct ceph_mds_session *session);
extern int ceph_restore_deleg_ino(struct ceph_mds_session *session, u64 ino);
#endif
@@ -816,6 +816,9 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
if (!fsc->cap_wq)
goto fail_inode_wq;
+ hash_init(fsc->async_unlink_conflict);
+ spin_lock_init(&fsc->async_unlink_conflict_lock);
+
spin_lock(&ceph_fsc_lock);
list_add_tail(&fsc->metric_wakeup, &ceph_fsc_list);
spin_unlock(&ceph_fsc_lock);
@@ -19,6 +19,7 @@
#include <linux/security.h>
#include <linux/netfs.h>
#include <linux/fscache.h>
+#include <linux/hashtable.h>
#include <linux/ceph/libceph.h>
@@ -99,6 +100,8 @@ struct ceph_mount_options {
char *mon_addr;
};
+#define CEPH_ASYNC_CREATE_CONFLICT_BITS 8
+
struct ceph_fs_client {
struct super_block *sb;
@@ -124,6 +127,9 @@ struct ceph_fs_client {
struct workqueue_struct *inode_wq;
struct workqueue_struct *cap_wq;
+ DECLARE_HASHTABLE(async_unlink_conflict, CEPH_ASYNC_CREATE_CONFLICT_BITS);
+ spinlock_t async_unlink_conflict_lock;
+
#ifdef CONFIG_DEBUG_FS
struct dentry *debugfs_dentry_lru, *debugfs_caps;
struct dentry *debugfs_congestion_kb;
@@ -281,7 +287,8 @@ struct ceph_dentry_info {
struct dentry *dentry;
struct ceph_mds_session *lease_session;
struct list_head lease_list;
- unsigned flags;
+ struct hlist_node hnode;
+ unsigned long flags;
int lease_shared_gen;
u32 lease_gen;
u32 lease_seq;
@@ -290,10 +297,12 @@ struct ceph_dentry_info {
u64 offset;
};
-#define CEPH_DENTRY_REFERENCED 1
-#define CEPH_DENTRY_LEASE_LIST 2
-#define CEPH_DENTRY_SHRINK_LIST 4
-#define CEPH_DENTRY_PRIMARY_LINK 8
+#define CEPH_DENTRY_REFERENCED (1 << 0)
+#define CEPH_DENTRY_LEASE_LIST (1 << 1)
+#define CEPH_DENTRY_SHRINK_LIST (1 << 2)
+#define CEPH_DENTRY_PRIMARY_LINK (1 << 3)
+#define CEPH_DENTRY_ASYNC_UNLINK_BIT (4)
+#define CEPH_DENTRY_ASYNC_UNLINK (1 << CEPH_DENTRY_ASYNC_UNLINK_BIT)
struct ceph_inode_xattrs_info {
/*