The use of wait_on_atomic_t() for waiting on I/O to complete before
unlocking allows us to git rid of the NFS_IO_INPROGRESS flag, and thus the
nfs_iocounter's flags member, and finally the nfs_iocounter altogether.
The count of I/O is moved to the lock context, and the counter
increment/decrement functions become simple enough to open-code.
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
---
fs/nfs/file.c | 2 +-
fs/nfs/inode.c | 18 ++++++++++++------
fs/nfs/internal.h | 9 ++-------
fs/nfs/pagelist.c | 48 +++++++-----------------------------------------
include/linux/nfs_fs.h | 8 +-------
5 files changed, 23 insertions(+), 62 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 93e2364..37ded36 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -756,7 +756,7 @@ do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
l_ctx = nfs_get_lock_context(nfs_file_open_context(filp));
if (!IS_ERR(l_ctx)) {
- status = nfs_iocounter_wait(&l_ctx->io_count);
+ status = nfs_iocounter_wait(l_ctx);
nfs_put_lock_context(l_ctx);
if (status < 0)
return status;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index c7e8b87..c1bfee4 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -71,19 +71,25 @@ nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
return nfs_fileid_to_ino_t(fattr->fileid);
}
-/**
- * nfs_wait_bit_killable - helper for functions that are sleeping on bit locks
- * @word: long word containing the bit lock
- */
-int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
+static int nfs_wait_killable(int mode)
{
freezable_schedule_unsafe();
if (signal_pending_state(mode, current))
return -ERESTARTSYS;
return 0;
}
+
+int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
+{
+ return nfs_wait_killable(mode);
+}
EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
+int nfs_wait_atomic_killable(atomic_t *p)
+{
+ return nfs_wait_killable(TASK_KILLABLE);
+}
+
/**
* nfs_compat_user_ino64 - returns the user-visible inode number
* @fileid: 64-bit fileid
@@ -699,7 +705,7 @@ 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);
+ atomic_set(&l_ctx->io_count, 0);
}
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 9dea85f..6c9b72f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -238,7 +238,7 @@ 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);
+int nfs_iocounter_wait(struct nfs_lock_context *l_ctx);
extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
@@ -252,12 +252,6 @@ void nfs_free_request(struct nfs_page *req);
struct nfs_pgio_mirror *
nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc);
-static inline void nfs_iocounter_init(struct nfs_io_counter *c)
-{
- c->flags = 0;
- atomic_set(&c->io_count, 0);
-}
-
static inline bool nfs_pgio_has_mirroring(struct nfs_pageio_descriptor *desc)
{
WARN_ON_ONCE(desc->pg_mirror_count < 1);
@@ -380,6 +374,7 @@ extern void nfs_clear_inode(struct inode *);
extern void nfs_evict_inode(struct inode *);
void nfs_zap_acl_cache(struct inode *inode);
extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode);
+extern int nfs_wait_atomic_killable(atomic_t *p);
/* super.c */
extern const struct super_operations nfs_sops;
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 452a011..abf1dad 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -101,53 +101,18 @@ 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_atomic();
- 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(&q.key, TASK_KILLABLE);
- } while (atomic_read(&c->io_count) != 0 && !ret);
- finish_wait(wq, &q.wait);
- return ret;
-}
-
/**
* nfs_iocounter_wait - wait for i/o to complete
- * @c: nfs_io_counter to use
+ * @l_ctx: nfs_lock_context with 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)
+nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
{
- if (atomic_read(&c->io_count) == 0)
- return 0;
- return __nfs_iocounter_wait(c);
+ return wait_on_atomic_t(&l_ctx->io_count, nfs_wait_atomic_killable,
+ TASK_KILLABLE);
}
/*
@@ -370,7 +335,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page,
return ERR_CAST(l_ctx);
}
req->wb_lock_context = l_ctx;
- nfs_iocounter_inc(&l_ctx->io_count);
+ atomic_inc(&l_ctx->io_count);
/* Initialize the request struct. Initially, we assume a
* long write-back delay. This will be adjusted in
@@ -431,7 +396,8 @@ static void nfs_clear_request(struct nfs_page *req)
req->wb_page = NULL;
}
if (l_ctx != NULL) {
- nfs_iocounter_dec(&l_ctx->io_count);
+ if (atomic_dec_and_test(&l_ctx->io_count))
+ wake_up_atomic_t(&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 c0e9614..de6ba5a 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -60,18 +60,12 @@ 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;
+ atomic_t io_count;
};
struct nfs4_state;
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
