[PATCH 11/24] pnfs_submit: expose pnfs_update_layout, put_lseg, and get_lseg functions

Fred Isaman
2010-06-08T04:19:47Z

These will be used in the generic code. Set so they will compile away to
nothing if CONFIG_NFS_V4_1 not set.

This requires kref_put to be under lock. See rule 3 of Documentation/kref.txt

Signed-off-by: Fred Isaman <iisaman@netapp.com>
---
fs/nfs/pnfs.c | 45 ++++++++++++++++++++++++++++++++-------------
fs/nfs/pnfs.h | 44 +++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 75 insertions(+), 14 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 836cb0f..a74a4b6 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -436,7 +436,25 @@ destroy_lseg(struct kref *kref)
PNFS_LD_IO_OPS(lseg->layout)->free_lseg(lseg);
}

-static inline void
+static void
+put_lseg_locked(struct pnfs_layout_segment *lseg)
+{
+ bool do_wake_up;
+ struct nfs_inode *nfsi;
+
+ if (!lseg)
+ return;
+
+ dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
+ atomic_read(&lseg->kref.refcount), lseg->valid);
+ do_wake_up = !lseg->valid;
+ nfsi = PNFS_NFS_INODE(lseg->layout);
+ kref_put(&lseg->kref, destroy_lseg);
+ if (do_wake_up)
+ wake_up(&nfsi->lo_waitq);
+}
+
+void
put_lseg(struct pnfs_layout_segment *lseg)
{
bool do_wake_up;
@@ -449,7 +467,9 @@ put_lseg(struct pnfs_layout_segment *lseg)
atomic_read(&lseg->kref.refcount), lseg->valid);
do_wake_up = !lseg->valid;
nfsi = PNFS_NFS_INODE(lseg->layout);
+ lock_current_layout(nfsi);
kref_put(&lseg->kref, destroy_lseg);
+ unlock_current_layout(nfsi);
if (do_wake_up)
wake_up(&nfsi->lo_waitq);
}
@@ -674,7 +694,7 @@ pnfs_free_layout(struct pnfs_layout_type *lo,
lseg, lseg->range.iomode, lseg->range.offset,
lseg->range.length);
list_del(&lseg->fi_list);
- put_lseg(lseg);
+ put_lseg_locked(lseg);
}

dprintk("%s:Return\n", __func__);
@@ -1033,7 +1053,7 @@ pnfs_has_layout(struct pnfs_layout_type *lo,
(lseg->valid || !only_valid)) {
ret = lseg;
if (take_ref)
- kref_get(&ret->kref);
+ get_lseg(ret);
break;
}
if (cmp_layout(range, &lseg->range) > 0)
@@ -1053,7 +1073,7 @@ pnfs_has_layout(struct pnfs_layout_type *lo,
* returned to the caller.
*/
int
-pnfs_update_layout(struct inode *ino,
+_pnfs_update_layout(struct inode *ino,
struct nfs_open_context *ctx,
u64 count,
loff_t pos,
@@ -1085,8 +1105,7 @@ pnfs_update_layout(struct inode *ino,
lseg = pnfs_has_layout(lo, &arg, take_ref, !take_ref);
if (lseg && !lseg->valid) {
if (take_ref)
- put_lseg(lseg);
-
+ put_lseg_locked(lseg);
/* someone is cleaning the layout */
lseg = NULL;
result = -EAGAIN;
@@ -1262,7 +1281,7 @@ pnfs_layout_process(struct nfs4_pnfs_layoutget *lgp)
init_lseg(lo, lseg);
lseg->range = res->lseg;
if (lgp->lsegpp) {
- kref_get(&lseg->kref);
+ get_lseg(lseg);
*lgp->lsegpp = lseg;
}

@@ -1380,7 +1399,7 @@ pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
readahead_range(inode, pages, &loff, &count);

if (count > 0) {
- status = pnfs_update_layout(inode, ctx, count,
+ status = _pnfs_update_layout(inode, ctx, count,
loff, IOMODE_READ, NULL);
dprintk("%s virt update returned %d\n", __func__, status);
if (status != 0)
@@ -1438,7 +1457,7 @@ pnfs_update_layout_commit(struct inode *inode,
if (start == 0 && count == 0)
count = NFS4_MAX_UINT64;

- status = pnfs_update_layout(inode, nfs_page->wb_context,
+ status = _pnfs_update_layout(inode, nfs_page->wb_context,
count,
start,
IOMODE_RW,
@@ -1538,7 +1557,7 @@ pnfs_file_write(struct file *filp, const char __user *buf, size_t count,
goto out;

/* Retrieve and set layout if not allready cached */
- status = pnfs_update_layout(inode,
+ status = _pnfs_update_layout(inode,
context,
count,
*pos,
@@ -1580,7 +1599,7 @@ pnfs_writepages(struct nfs_write_data *wdata, int how)
args->offset);

/* Retrieve and set layout if not allready cached */
- status = pnfs_update_layout(inode,
+ status = _pnfs_update_layout(inode,
args->context,
args->count,
args->offset,
@@ -1681,7 +1700,7 @@ pnfs_readpages(struct nfs_read_data *rdata)
args->offset);

/* Retrieve and set layout if not allready cached */
- status = pnfs_update_layout(inode,
+ status = _pnfs_update_layout(inode,
args->context,
args->count,
args->offset,
@@ -1845,7 +1864,7 @@ pnfs_commit(struct nfs_write_data *data, int sync)
new one. If it was recalled we better commit the data first
before returning it, otherwise the data needs to be rewritten,
either with a new layout or to the MDS */
- result = pnfs_update_layout(data->inode,
+ result = _pnfs_update_layout(data->inode,
NULL,
count,
first->wb_offset,
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 214d567..6326ed5 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -31,7 +31,8 @@ extern int pnfs4_proc_layoutreturn(struct nfs4_pnfs_layoutreturn *lrp, bool wait
/* pnfs.c */
extern const nfs4_stateid zero_stateid;

-int pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
+void put_lseg(struct pnfs_layout_segment *lseg);
+int _pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
u64 count, loff_t pos, enum pnfs_iomode access_type,
struct pnfs_layout_segment **lsegpp);

@@ -81,6 +82,12 @@ static inline int lo_fail_bit(u32 iomode)
NFS_INO_RW_LAYOUT_FAILED : NFS_INO_RO_LAYOUT_FAILED;
}

+static inline void get_lseg(struct pnfs_layout_segment *lseg)
+{
+ if (lseg)
+ kref_get(&lseg->kref);
+}
+
/* Return true if a layout driver is being used for this mountpoint */
static inline int pnfs_enabled_sb(struct nfs_server *nfss)
{
@@ -170,6 +177,23 @@ static inline int pnfs_return_layout(struct inode *ino,
return 0;
}

+static inline int pnfs_update_layout(struct inode *ino,
+ struct nfs_open_context *ctx,
+ u64 count, loff_t pos, enum pnfs_iomode access_type,
+ struct pnfs_layout_segment **lsegpp)
+{
+ struct nfs_server *nfss = NFS_SERVER(ino);
+
+ if (pnfs_enabled_sb(nfss))
+ return _pnfs_update_layout(ino, ctx, count, pos,
+ access_type, lsegpp);
+ else {
+ if (lsegpp)
+ *lsegpp = NULL;
+ return 0;
+ }
+}
+
static inline int pnfs_get_write_status(struct nfs_write_data *data)
{
return data->pdata.pnfs_error;
@@ -190,6 +214,24 @@ static inline int pnfs_use_rpc(struct nfs_server *nfss)

#else /* CONFIG_NFS_V4_1 */

+static inline void get_lseg(struct pnfs_layout_segment *lseg)
+{
+}
+
+static inline void put_lseg(struct pnfs_layout_segment *lseg)
+{
+}
+
+static inline int
+pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
+ u64 count, loff_t pos, enum pnfs_iomode access_type,
+ struct pnfs_layout_segment **lsegpp)
+{
+ if (lsegpp)
+ *lsegpp = NULL;
+ return 0;
+}
+
static inline enum pnfs_try_status
pnfs_try_to_read_data(struct nfs_read_data *data,
const struct rpc_call_ops *call_ops)
--
1.6.6.1