This will later allow NFS locking code to wait for readahead to complete
before releasing byte range locks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
fs/nfs/inode.c | 1 +
fs/nfs/internal.h | 7 +++++++
fs/nfs/pagelist.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/nfs_fs.h | 7 +++++++
4 files changed, 66 insertions(+)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 55b840f..c1c7a9d 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -561,6 +561,7 @@ static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
l_ctx->lockowner.l_owner = current->files;
l_ctx->lockowner.l_pid = current->tgid;
INIT_LIST_HEAD(&l_ctx->list);
+ nfs_iocounter_init(&l_ctx->io_count);
}
static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 541c9eb..91e59a3 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -229,6 +229,13 @@ extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
struct nfs_pgio_header *hdr,
void (*release)(struct nfs_pgio_header *hdr));
void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
+int nfs_iocounter_wait(struct nfs_io_counter *c);
+
+static inline void nfs_iocounter_init(struct nfs_io_counter *c)
+{
+ c->flags = 0;
+ atomic_set(&c->io_count, 0);
+}
/* nfs2xdr.c */
extern struct rpc_procinfo nfs_procedures[];
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 7f09330..29cfb7a 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -84,6 +84,55 @@ nfs_page_free(struct nfs_page *p)
kmem_cache_free(nfs_page_cachep, p);
}
+static void
+nfs_iocounter_inc(struct nfs_io_counter *c)
+{
+ atomic_inc(&c->io_count);
+}
+
+static void
+nfs_iocounter_dec(struct nfs_io_counter *c)
+{
+ if (atomic_dec_and_test(&c->io_count)) {
+ clear_bit(NFS_IO_INPROGRESS, &c->flags);
+ smp_mb__after_clear_bit();
+ wake_up_bit(&c->flags, NFS_IO_INPROGRESS);
+ }
+}
+
+static int
+__nfs_iocounter_wait(struct nfs_io_counter *c)
+{
+ wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS);
+ DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS);
+ int ret = 0;
+
+ do {
+ prepare_to_wait(wq, &q.wait, TASK_KILLABLE);
+ set_bit(NFS_IO_INPROGRESS, &c->flags);
+ if (atomic_read(&c->io_count) == 0)
+ break;
+ ret = nfs_wait_bit_killable(&c->flags);
+ } while (atomic_read(&c->io_count) != 0);
+ finish_wait(wq, &q.wait);
+ return ret;
+}
+
+/**
+ * nfs_iocounter_wait - wait for i/o to complete
+ * @c: nfs_io_counter to use
+ *
+ * returns -ERESTARTSYS if interrupted by a fatal signal.
+ * Otherwise returns 0 once the io_count hits 0.
+ */
+int
+nfs_iocounter_wait(struct nfs_io_counter *c)
+{
+ if (atomic_read(&c->io_count) == 0)
+ return 0;
+ return __nfs_iocounter_wait(c);
+}
+
/**
* nfs_create_request - Create an NFS read/write request.
* @ctx: open context to use
@@ -118,6 +167,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
return ERR_CAST(l_ctx);
}
req->wb_lock_context = l_ctx;
+ nfs_iocounter_inc(&l_ctx->io_count);
/* Initialize the request struct. Initially, we assume a
* long write-back delay. This will be adjusted in
@@ -177,6 +227,7 @@ static void nfs_clear_request(struct nfs_page *req)
req->wb_page = NULL;
}
if (l_ctx != NULL) {
+ nfs_iocounter_dec(&l_ctx->io_count);
nfs_put_lock_context(l_ctx);
req->wb_lock_context = NULL;
}
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index f6b1956..fc01d5c 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -59,11 +59,18 @@ struct nfs_lockowner {
pid_t l_pid;
};
+#define NFS_IO_INPROGRESS 0
+struct nfs_io_counter {
+ unsigned long flags;
+ atomic_t io_count;
+};
+
struct nfs_lock_context {
atomic_t count;
struct list_head list;
struct nfs_open_context *open_context;
struct nfs_lockowner lockowner;
+ struct nfs_io_counter io_count;
};
struct nfs4_state;
--
1.8.1.4
--
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