[PATCH 15/24] pnfs_submit: stash and refcount lseg in write path

Fred Isaman
2010-06-08T04:19:48Z

Store the lseg in each nfs_page. Note this necessitates adding checks
for compatibility with pre-existing nfs_pages lsegs.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
---
fs/nfs/file.c | 14 +++++++++-----
fs/nfs/write.c | 30 ++++++++++++++++++------------
include/linux/nfs_fs.h | 8 ++++++--
3 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index fde6cb5..7cdc2b7 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -420,7 +420,9 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
file->f_path.dentry->d_name.name,
mapping->host->i_ino, len, (long long) pos);

- pnfs_update_layout(mapping->host, NULL, NFS4_MAX_UINT64, 0, IOMODE_RW,
+ pnfs_update_layout(mapping->host,
+ nfs_file_open_context(file),
+ NFS4_MAX_UINT64, 0, IOMODE_RW,
(struct pnfs_layout_segment **) fsdata);
start:
/*
@@ -439,7 +441,7 @@ start:
}
*pagep = page;

- ret = nfs_flush_incompatible(file, page);
+ ret = nfs_flush_incompatible(file, page, *fsdata);
if (ret) {
unlock_page(page);
page_cache_release(page);
@@ -491,7 +493,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
zero_user_segment(page, pglen, PAGE_CACHE_SIZE);
}

- status = nfs_updatepage(file, page, offset, copied);
+ status = nfs_updatepage(file, page, offset, copied, fsdata);

unlock_page(page);
page_cache_release(page);
@@ -598,6 +600,8 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
/* make sure the cache has finished storing the page */
nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page);

+ /* XXX Do we want to call pnfs_update_layout here? */
+
lock_page(page);
mapping = page->mapping;
if (mapping != dentry->d_inode->i_mapping)
@@ -608,11 +612,11 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
if (pagelen == 0)
goto out_unlock;

- ret = nfs_flush_incompatible(filp, page);
+ ret = nfs_flush_incompatible(filp, page, NULL);
if (ret != 0)
goto out_unlock;

- ret = nfs_updatepage(filp, page, 0, pagelen);
+ ret = nfs_updatepage(filp, page, 0, pagelen, NULL);
out_unlock:
if (!ret)
return VM_FAULT_LOCKED;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index d8c0453..e2fbddb 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -570,7 +570,8 @@ static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, pg
static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
struct page *page,
unsigned int offset,
- unsigned int bytes)
+ unsigned int bytes,
+ struct pnfs_layout_segment *lseg)
{
struct nfs_page *req;
unsigned int rqend;
@@ -595,8 +596,8 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
* Note: nfs_flush_incompatible() will already
* have flushed out requests having wrong owners.
*/
- if (offset > rqend
- || end < req->wb_offset)
+ if (offset > rqend || end < req->wb_offset ||
+ req->wb_lseg != lseg)
goto out_flushme;

if (nfs_set_page_tag_locked(req))
@@ -644,16 +645,17 @@ out_err:
* already called nfs_flush_incompatible() if necessary.
*/
static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
- struct page *page, unsigned int offset, unsigned int bytes)
+ struct page *page, unsigned int offset, unsigned int bytes,
+ struct pnfs_layout_segment *lseg)
{
struct inode *inode = page->mapping->host;
struct nfs_page *req;
int error;

- req = nfs_try_to_update_request(inode, page, offset, bytes);
+ req = nfs_try_to_update_request(inode, page, offset, bytes, lseg);
if (req != NULL)
goto out;
- req = nfs_create_request(ctx, inode, page, offset, bytes, NULL);
+ req = nfs_create_request(ctx, inode, page, offset, bytes, lseg);
if (IS_ERR(req))
goto out;
error = nfs_inode_add_request(inode, req);
@@ -666,11 +668,12 @@ out:
}

static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
- unsigned int offset, unsigned int count)
+ unsigned int offset, unsigned int count,
+ struct pnfs_layout_segment *lseg)
{
struct nfs_page *req;

- req = nfs_setup_write_request(ctx, page, offset, count);
+ req = nfs_setup_write_request(ctx, page, offset, count, lseg);
if (IS_ERR(req))
return PTR_ERR(req);
nfs_mark_request_dirty(req);
@@ -682,7 +685,8 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
return 0;
}

-int nfs_flush_incompatible(struct file *file, struct page *page)
+int nfs_flush_incompatible(struct file *file, struct page *page,
+ struct pnfs_layout_segment *lseg)
{
struct nfs_open_context *ctx = nfs_file_open_context(file);
struct nfs_page *req;
@@ -699,7 +703,8 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
req = nfs_page_find_request(page);
if (req == NULL)
return 0;
- do_flush = req->wb_page != page || req->wb_context != ctx;
+ do_flush = req->wb_page != page || req->wb_context != ctx ||
+ req->wb_lseg != lseg;
nfs_release_request(req);
if (!do_flush)
return 0;
@@ -726,7 +731,8 @@ static int nfs_write_pageuptodate(struct page *page, struct inode *inode)
* things with a page scheduled for an RPC call (e.g. invalidate it).
*/
int nfs_updatepage(struct file *file, struct page *page,
- unsigned int offset, unsigned int count)
+ unsigned int offset, unsigned int count,
+ struct pnfs_layout_segment *lseg)
{
struct nfs_open_context *ctx = nfs_file_open_context(file);
struct inode *inode = page->mapping->host;
@@ -751,7 +757,7 @@ int nfs_updatepage(struct file *file, struct page *page,
offset = 0;
}

- status = nfs_writepage_setup(ctx, page, offset, count);
+ status = nfs_writepage_setup(ctx, page, offset, count, lseg);
if (status < 0)
nfs_set_pageerror(page);

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index ee45eac..0de7847 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -512,8 +512,12 @@ extern void nfs_unblock_sillyrename(struct dentry *dentry);
extern int nfs_congestion_kb;
extern int nfs_writepage(struct page *page, struct writeback_control *wbc);
extern int nfs_writepages(struct address_space *, struct writeback_control *);
-extern int nfs_flush_incompatible(struct file *file, struct page *page);
-extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
+struct pnfs_layout_segment;
+extern int nfs_flush_incompatible(struct file *file, struct page *page,
+ struct pnfs_layout_segment *lseg);
+extern int nfs_updatepage(struct file *, struct page *,
+ unsigned int offset, unsigned int count,
+ struct pnfs_layout_segment *lseg);
extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);

/*
--
1.6.6.1