[ 047/150] NFSv4.1: Fix bulk recall and destroy of layouts

Greg Kroah-Hartman
2013-02-27T01:10:00Z

From: Trond Myklebust <Trond.Myklebust@netapp.com>

commit fd9a8d7160937f94aad36ac80d7255b4988740ac upstream.

The current code in pnfs_destroy_all_layouts() assumes that removing
the layout from the server->layouts list is sufficient to make it
invisible to other processes. This ignores the fact that most
users access the layout through the nfs_inode->layout...
There is further breakage due to lack of reference counting of the
layouts, meaning that the whole thing Oopses at the drop of a hat.

The code in initiate_bulk_draining() is almost correct, and can be
used as a model for pnfs_destroy_all_layouts(), so move that
code to pnfs.c, and refactor the code to allow us to choose between
a single filesystem bulk recall, and a recall of all layouts.
Also note that initiate_bulk_draining() currently calls iput() while
holding locks. Fix that too.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfs/callback_proc.c | 61 ++-----------------
fs/nfs/pnfs.c | 150 ++++++++++++++++++++++++++++++++++++++++++-------
fs/nfs/pnfs.h | 7 +-
3 files changed, 144 insertions(+), 74 deletions(-)

--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -183,60 +183,15 @@ static u32 initiate_file_draining(struct
static u32 initiate_bulk_draining(struct nfs_client *clp,
struct cb_layoutrecallargs *args)
{
- struct nfs_server *server;
- struct pnfs_layout_hdr *lo;
- struct inode *ino;
- u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
- struct pnfs_layout_hdr *tmp;
- LIST_HEAD(recall_list);
- LIST_HEAD(free_me_list);
- struct pnfs_layout_range range = {
- .iomode = IOMODE_ANY,
- .offset = 0,
- .length = NFS4_MAX_UINT64,
- };
+ int stat;

- spin_lock(&clp->cl_lock);
- rcu_read_lock();
- list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
- if ((args->cbl_recall_type == RETURN_FSID) &&
- memcmp(&server->fsid, &args->cbl_fsid,
- sizeof(struct nfs_fsid)))
- continue;
-
- list_for_each_entry(lo, &server->layouts, plh_layouts) {
- ino = igrab(lo->plh_inode);
- if (!ino)
- continue;
- spin_lock(&ino->i_lock);
- /* Is this layout in the process of being freed? */
- if (NFS_I(ino)->layout != lo) {
- spin_unlock(&ino->i_lock);
- iput(ino);
- continue;
- }
- pnfs_get_layout_hdr(lo);
- spin_unlock(&ino->i_lock);
- list_add(&lo->plh_bulk_recall, &recall_list);
- }
- }
- rcu_read_unlock();
- spin_unlock(&clp->cl_lock);
-
- list_for_each_entry_safe(lo, tmp,
- &recall_list, plh_bulk_recall) {
- ino = lo->plh_inode;
- spin_lock(&ino->i_lock);
- set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
- if (pnfs_mark_matching_lsegs_invalid(lo, &free_me_list, &range))
- rv = NFS4ERR_DELAY;
- list_del_init(&lo->plh_bulk_recall);
- spin_unlock(&ino->i_lock);
- pnfs_free_lseg_list(&free_me_list);
- pnfs_put_layout_hdr(lo);
- iput(ino);
- }
- return rv;
+ if (args->cbl_recall_type == RETURN_FSID)
+ stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
+ else
+ stat = pnfs_destroy_layouts_byclid(clp, true);
+ if (stat != 0)
+ return NFS4ERR_DELAY;
+ return NFS4ERR_NOMATCHING_LAYOUT;
}

static u32 do_callback_layoutrecall(struct nfs_client *clp,
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -505,37 +505,147 @@ pnfs_destroy_layout(struct nfs_inode *nf
}
EXPORT_SYMBOL_GPL(pnfs_destroy_layout);

-/*
- * Called by the state manger to remove all layouts established under an
- * expired lease.
- */
-void
-pnfs_destroy_all_layouts(struct nfs_client *clp)
+static bool
+pnfs_layout_add_bulk_destroy_list(struct inode *inode,
+ struct list_head *layout_list)
{
- struct nfs_server *server;
struct pnfs_layout_hdr *lo;
- LIST_HEAD(tmp_list);
+ bool ret = false;

- nfs4_deviceid_mark_client_invalid(clp);
- nfs4_deviceid_purge_client(clp);
+ spin_lock(&inode->i_lock);
+ lo = NFS_I(inode)->layout;
+ if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
+ pnfs_get_layout_hdr(lo);
+ list_add(&lo->plh_bulk_destroy, layout_list);
+ ret = true;
+ }
+ spin_unlock(&inode->i_lock);
+ return ret;
+}
+
+/* Caller must hold rcu_read_lock and clp->cl_lock */
+static int
+pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
+ struct nfs_server *server,
+ struct list_head *layout_list)
+{
+ struct pnfs_layout_hdr *lo, *next;
+ struct inode *inode;
+
+ list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
+ inode = igrab(lo->plh_inode);
+ if (inode == NULL)
+ continue;
+ list_del_init(&lo->plh_layouts);
+ if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
+ continue;
+ rcu_read_unlock();
+ spin_unlock(&clp->cl_lock);
+ iput(inode);
+ spin_lock(&clp->cl_lock);
+ rcu_read_lock();
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static int
+pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
+ bool is_bulk_recall)
+{
+ struct pnfs_layout_hdr *lo;
+ struct inode *inode;
+ struct pnfs_layout_range range = {
+ .iomode = IOMODE_ANY,
+ .offset = 0,
+ .length = NFS4_MAX_UINT64,
+ };
+ LIST_HEAD(lseg_list);
+ int ret = 0;
+
+ while (!list_empty(layout_list)) {
+ lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
+ plh_bulk_destroy);
+ dprintk("%s freeing layout for inode %lu\n", __func__,
+ lo->plh_inode->i_ino);
+ inode = lo->plh_inode;
+ spin_lock(&inode->i_lock);
+ list_del_init(&lo->plh_bulk_destroy);
+ lo->plh_block_lgets++; /* permanently block new LAYOUTGETs */
+ if (is_bulk_recall)
+ set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
+ if (pnfs_mark_matching_lsegs_invalid(lo, &lseg_list, &range))
+ ret = -EAGAIN;
+ spin_unlock(&inode->i_lock);
+ pnfs_free_lseg_list(&lseg_list);
+ pnfs_put_layout_hdr(lo);
+ iput(inode);
+ }
+ return ret;
+}
+
+int
+pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
+ struct nfs_fsid *fsid,
+ bool is_recall)
+{
+ struct nfs_server *server;
+ LIST_HEAD(layout_list);

spin_lock(&clp->cl_lock);
rcu_read_lock();
+restart:
list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
- if (!list_empty(&server->layouts))
- list_splice_init(&server->layouts, &tmp_list);
+ if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
+ continue;
+ if (pnfs_layout_bulk_destroy_byserver_locked(clp,
+ server,
+ &layout_list) != 0)
+ goto restart;
}
rcu_read_unlock();
spin_unlock(&clp->cl_lock);

- while (!list_empty(&tmp_list)) {
- lo = list_entry(tmp_list.next, struct pnfs_layout_hdr,
- plh_layouts);
- dprintk("%s freeing layout for inode %lu\n", __func__,
- lo->plh_inode->i_ino);
- list_del_init(&lo->plh_layouts);
- pnfs_destroy_layout(NFS_I(lo->plh_inode));
+ if (list_empty(&layout_list))
+ return 0;
+ return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
+}
+
+int
+pnfs_destroy_layouts_byclid(struct nfs_client *clp,
+ bool is_recall)
+{
+ struct nfs_server *server;
+ LIST_HEAD(layout_list);
+
+ spin_lock(&clp->cl_lock);
+ rcu_read_lock();
+restart:
+ list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+ if (pnfs_layout_bulk_destroy_byserver_locked(clp,
+ server,
+ &layout_list) != 0)
+ goto restart;
}
+ rcu_read_unlock();
+ spin_unlock(&clp->cl_lock);
+
+ if (list_empty(&layout_list))
+ return 0;
+ return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
+}
+
+/*
+ * Called by the state manger to remove all layouts established under an
+ * expired lease.
+ */
+void
+pnfs_destroy_all_layouts(struct nfs_client *clp)
+{
+ nfs4_deviceid_mark_client_invalid(clp);
+ nfs4_deviceid_purge_client(clp);
+
+ pnfs_destroy_layouts_byclid(clp, false);
}

/*
@@ -888,7 +998,7 @@ alloc_init_layout_hdr(struct inode *ino,
atomic_set(&lo->plh_refcount, 1);
INIT_LIST_HEAD(&lo->plh_layouts);
INIT_LIST_HEAD(&lo->plh_segs);
- INIT_LIST_HEAD(&lo->plh_bulk_recall);
+ INIT_LIST_HEAD(&lo->plh_bulk_destroy);
lo->plh_inode = ino;
lo->plh_lc_cred = get_rpccred(ctx->state->owner->so_cred);
return lo;
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -132,7 +132,7 @@ struct pnfs_layoutdriver_type {
struct pnfs_layout_hdr {
atomic_t plh_refcount;
struct list_head plh_layouts; /* other client layouts */
- struct list_head plh_bulk_recall; /* clnt list of bulk recalls */
+ struct list_head plh_bulk_destroy;
struct list_head plh_segs; /* layout segments list */
nfs4_stateid plh_stateid;
atomic_t plh_outstanding; /* number of RPCs out */
@@ -196,6 +196,11 @@ struct pnfs_layout_segment *pnfs_layout_
void pnfs_free_lseg_list(struct list_head *tmp_list);
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
+int pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
+ struct nfs_fsid *fsid,
+ bool is_recall);
+int pnfs_destroy_layouts_byclid(struct nfs_client *clp,
+ bool is_recall);
void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo);
void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
const nfs4_stateid *new,