* [PATCH 01/10] NFS: Clean up nfs_readpage() and nfs_readpages()
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
@ 2021-01-28 14:54 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 02/10] NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read succeeds Dave Wysochanski
` (9 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:54 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
In prep for the new fscache netfs API, refactor nfs_readpage()
and nfs_readpages() for future patches. No functional change.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/read.c | 45 +++++++++++++++++++++++----------------------
1 file changed, 23 insertions(+), 22 deletions(-)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index eb854f1f86e2..dd92156e27c5 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -314,7 +314,7 @@ int nfs_readpage(struct file *file, struct page *page)
{
struct nfs_open_context *ctx;
struct inode *inode = page_file_mapping(page)->host;
- int error;
+ int ret;
dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
page, PAGE_SIZE, page_index(page));
@@ -328,18 +328,18 @@ int nfs_readpage(struct file *file, struct page *page)
* be any new pending writes generated at this point
* for this page (other pages can be written to).
*/
- error = nfs_wb_page(inode, page);
- if (error)
+ ret = nfs_wb_page(inode, page);
+ if (ret)
goto out_unlock;
if (PageUptodate(page))
goto out_unlock;
- error = -ESTALE;
+ ret = -ESTALE;
if (NFS_STALE(inode))
goto out_unlock;
if (file == NULL) {
- error = -EBADF;
+ ret = -EBADF;
ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (ctx == NULL)
goto out_unlock;
@@ -347,24 +347,24 @@ int nfs_readpage(struct file *file, struct page *page)
ctx = get_nfs_open_context(nfs_file_open_context(file));
if (!IS_SYNC(inode)) {
- error = nfs_readpage_from_fscache(ctx, inode, page);
- if (error == 0)
+ ret = nfs_readpage_from_fscache(ctx, inode, page);
+ if (ret == 0)
goto out;
}
xchg(&ctx->error, 0);
- error = nfs_readpage_async(ctx, inode, page);
- if (!error) {
- error = wait_on_page_locked_killable(page);
- if (!PageUptodate(page) && !error)
- error = xchg(&ctx->error, 0);
+ ret = nfs_readpage_async(ctx, inode, page);
+ if (!ret) {
+ ret = wait_on_page_locked_killable(page);
+ if (!PageUptodate(page) && !ret)
+ ret = xchg(&ctx->error, 0);
}
out:
put_nfs_open_context(ctx);
- return error;
+ return ret;
out_unlock:
unlock_page(page);
- return error;
+ return ret;
}
struct nfs_readdesc {
@@ -404,17 +404,15 @@ struct nfs_readdesc {
return error;
}
-int nfs_readpages(struct file *filp, struct address_space *mapping,
+int nfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct nfs_pageio_descriptor pgio;
struct nfs_pgio_mirror *pgm;
- struct nfs_readdesc desc = {
- .pgio = &pgio,
- };
+ struct nfs_readdesc desc;
struct inode *inode = mapping->host;
unsigned long npages;
- int ret = -ESTALE;
+ int ret;
dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
inode->i_sb->s_id,
@@ -422,15 +420,17 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
nr_pages);
nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
+ ret = -ESTALE;
if (NFS_STALE(inode))
goto out;
- if (filp == NULL) {
+ if (file == NULL) {
+ ret = -EBADF;
desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (desc.ctx == NULL)
- return -EBADF;
+ goto out;
} else
- desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
+ desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
/* attempt to read as many of the pages as possible from the cache
* - this returns -ENOBUFS immediately if the cookie is negative
@@ -440,6 +440,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
if (ret == 0)
goto read_complete; /* all pages were read */
+ desc.pgio = &pgio;
nfs_pageio_init_read(&pgio, inode, false,
&nfs_async_read_completion_ops);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 02/10] NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read succeeds
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
2021-01-28 14:54 ` [PATCH 01/10] NFS: Clean up nfs_readpage() and nfs_readpages() Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 03/10] NFS: Refactor nfs_readpage() and nfs_readpage_async() to use nfs_readdesc Dave Wysochanski
` (8 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
There is a small inconsistency with nfs_readpage() vs nfs_readpages() with
regards to NFSIOS_READPAGES. In readpage we unconditionally increment
NFSIOS_READPAGES at the top, which means even if the read fails. In
readpages, we increment NFSIOS_READPAGES at the bottom based on how
many pages were successfully read. Change readpage to be consistent with
readpages and so NFSIOS_READPAGES only reflects successful, non-fscache
reads.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/read.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index dd92156e27c5..464077daf62f 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -319,7 +319,6 @@ int nfs_readpage(struct file *file, struct page *page)
dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
page, PAGE_SIZE, page_index(page));
nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
- nfs_add_stats(inode, NFSIOS_READPAGES, 1);
/*
* Try to flush any pending writes to the file..
@@ -359,6 +358,7 @@ int nfs_readpage(struct file *file, struct page *page)
if (!PageUptodate(page) && !ret)
ret = xchg(&ctx->error, 0);
}
+ nfs_add_stats(inode, NFSIOS_READPAGES, 1);
out:
put_nfs_open_context(ctx);
return ret;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 03/10] NFS: Refactor nfs_readpage() and nfs_readpage_async() to use nfs_readdesc
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
2021-01-28 14:54 ` [PATCH 01/10] NFS: Clean up nfs_readpage() and nfs_readpages() Dave Wysochanski
2021-01-28 14:55 ` [PATCH 02/10] NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read succeeds Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 04/10] NFS: Call readpage_async_filler() from nfs_readpage_async() Dave Wysochanski
` (7 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
Both nfs_readpage() and nfs_readpages() use similar code.
This patch should be no functional change, and refactors
nfs_readpage_async() to use nfs_readdesc to enable future
merging of nfs_readpage_async() and nfs_readpage_async_filler().
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/read.c | 62 ++++++++++++++++++++++++--------------------------
include/linux/nfs_fs.h | 3 +--
2 files changed, 31 insertions(+), 34 deletions(-)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 464077daf62f..8c05e56dab65 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -114,18 +114,23 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
nfs_release_request(req);
}
-int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
+struct nfs_readdesc {
+ struct nfs_pageio_descriptor pgio;
+ struct nfs_open_context *ctx;
+};
+
+int nfs_readpage_async(void *data, struct inode *inode,
struct page *page)
{
+ struct nfs_readdesc *desc = data;
struct nfs_page *new;
unsigned int len;
- struct nfs_pageio_descriptor pgio;
struct nfs_pgio_mirror *pgm;
len = nfs_page_length(page);
if (len == 0)
return nfs_return_empty_page(page);
- new = nfs_create_request(ctx, page, 0, len);
+ new = nfs_create_request(desc->ctx, page, 0, len);
if (IS_ERR(new)) {
unlock_page(page);
return PTR_ERR(new);
@@ -133,21 +138,21 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
if (len < PAGE_SIZE)
zero_user_segment(page, len, PAGE_SIZE);
- nfs_pageio_init_read(&pgio, inode, false,
+ nfs_pageio_init_read(&desc->pgio, inode, false,
&nfs_async_read_completion_ops);
- if (!nfs_pageio_add_request(&pgio, new)) {
+ if (!nfs_pageio_add_request(&desc->pgio, new)) {
nfs_list_remove_request(new);
- nfs_readpage_release(new, pgio.pg_error);
+ nfs_readpage_release(new, desc->pgio.pg_error);
}
- nfs_pageio_complete(&pgio);
+ nfs_pageio_complete(&desc->pgio);
/* It doesn't make sense to do mirrored reads! */
- WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+ WARN_ON_ONCE(desc->pgio.pg_mirror_count != 1);
- pgm = &pgio.pg_mirrors[0];
+ pgm = &desc->pgio.pg_mirrors[0];
NFS_I(inode)->read_io += pgm->pg_bytes_written;
- return pgio.pg_error < 0 ? pgio.pg_error : 0;
+ return desc->pgio.pg_error < 0 ? desc->pgio.pg_error : 0;
}
static void nfs_page_group_set_uptodate(struct nfs_page *req)
@@ -312,7 +317,7 @@ static void nfs_readpage_result(struct rpc_task *task,
*/
int nfs_readpage(struct file *file, struct page *page)
{
- struct nfs_open_context *ctx;
+ struct nfs_readdesc desc;
struct inode *inode = page_file_mapping(page)->host;
int ret;
@@ -339,39 +344,34 @@ int nfs_readpage(struct file *file, struct page *page)
if (file == NULL) {
ret = -EBADF;
- ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
- if (ctx == NULL)
+ desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+ if (desc.ctx == NULL)
goto out_unlock;
} else
- ctx = get_nfs_open_context(nfs_file_open_context(file));
+ desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
if (!IS_SYNC(inode)) {
- ret = nfs_readpage_from_fscache(ctx, inode, page);
+ ret = nfs_readpage_from_fscache(desc.ctx, inode, page);
if (ret == 0)
goto out;
}
- xchg(&ctx->error, 0);
- ret = nfs_readpage_async(ctx, inode, page);
+ xchg(&desc.ctx->error, 0);
+ ret = nfs_readpage_async(&desc, inode, page);
if (!ret) {
ret = wait_on_page_locked_killable(page);
if (!PageUptodate(page) && !ret)
- ret = xchg(&ctx->error, 0);
+ ret = xchg(&desc.ctx->error, 0);
}
nfs_add_stats(inode, NFSIOS_READPAGES, 1);
out:
- put_nfs_open_context(ctx);
+ put_nfs_open_context(desc.ctx);
return ret;
out_unlock:
unlock_page(page);
return ret;
}
-struct nfs_readdesc {
- struct nfs_pageio_descriptor *pgio;
- struct nfs_open_context *ctx;
-};
-
static int
readpage_async_filler(void *data, struct page *page)
{
@@ -390,9 +390,9 @@ struct nfs_readdesc {
if (len < PAGE_SIZE)
zero_user_segment(page, len, PAGE_SIZE);
- if (!nfs_pageio_add_request(desc->pgio, new)) {
+ if (!nfs_pageio_add_request(&desc->pgio, new)) {
nfs_list_remove_request(new);
- error = desc->pgio->pg_error;
+ error = desc->pgio.pg_error;
nfs_readpage_release(new, error);
goto out;
}
@@ -407,7 +407,6 @@ struct nfs_readdesc {
int nfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
- struct nfs_pageio_descriptor pgio;
struct nfs_pgio_mirror *pgm;
struct nfs_readdesc desc;
struct inode *inode = mapping->host;
@@ -440,17 +439,16 @@ int nfs_readpages(struct file *file, struct address_space *mapping,
if (ret == 0)
goto read_complete; /* all pages were read */
- desc.pgio = &pgio;
- nfs_pageio_init_read(&pgio, inode, false,
+ nfs_pageio_init_read(&desc.pgio, inode, false,
&nfs_async_read_completion_ops);
ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
- nfs_pageio_complete(&pgio);
+ nfs_pageio_complete(&desc.pgio);
/* It doesn't make sense to do mirrored reads! */
- WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+ WARN_ON_ONCE(desc.pgio.pg_mirror_count != 1);
- pgm = &pgio.pg_mirrors[0];
+ pgm = &desc.pgio.pg_mirrors[0];
NFS_I(inode)->read_io += pgm->pg_bytes_written;
npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >>
PAGE_SHIFT;
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 681ed98e4ba8..cb0248a34518 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -570,8 +570,7 @@ extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred, s
extern int nfs_readpage(struct file *, struct page *);
extern int nfs_readpages(struct file *, struct address_space *,
struct list_head *, unsigned);
-extern int nfs_readpage_async(struct nfs_open_context *, struct inode *,
- struct page *);
+extern int nfs_readpage_async(void *, struct inode *, struct page *);
/*
* inline functions
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 04/10] NFS: Call readpage_async_filler() from nfs_readpage_async()
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (2 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 03/10] NFS: Refactor nfs_readpage() and nfs_readpage_async() to use nfs_readdesc Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 05/10] NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async() Dave Wysochanski
` (6 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
Refactor slightly so nfs_readpage_async() calls into
readpage_async_filler().
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/read.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 8c05e56dab65..0ed79e6bc486 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -119,31 +119,22 @@ struct nfs_readdesc {
struct nfs_open_context *ctx;
};
+static int readpage_async_filler(void *data, struct page *page);
+
int nfs_readpage_async(void *data, struct inode *inode,
struct page *page)
{
struct nfs_readdesc *desc = data;
- struct nfs_page *new;
- unsigned int len;
struct nfs_pgio_mirror *pgm;
-
- len = nfs_page_length(page);
- if (len == 0)
- return nfs_return_empty_page(page);
- new = nfs_create_request(desc->ctx, page, 0, len);
- if (IS_ERR(new)) {
- unlock_page(page);
- return PTR_ERR(new);
- }
- if (len < PAGE_SIZE)
- zero_user_segment(page, len, PAGE_SIZE);
+ int error;
nfs_pageio_init_read(&desc->pgio, inode, false,
&nfs_async_read_completion_ops);
- if (!nfs_pageio_add_request(&desc->pgio, new)) {
- nfs_list_remove_request(new);
- nfs_readpage_release(new, desc->pgio.pg_error);
- }
+
+ error = readpage_async_filler(desc, page);
+ if (error)
+ goto out;
+
nfs_pageio_complete(&desc->pgio);
/* It doesn't make sense to do mirrored reads! */
@@ -153,6 +144,9 @@ int nfs_readpage_async(void *data, struct inode *inode,
NFS_I(inode)->read_io += pgm->pg_bytes_written;
return desc->pgio.pg_error < 0 ? desc->pgio.pg_error : 0;
+
+out:
+ return error;
}
static void nfs_page_group_set_uptodate(struct nfs_page *req)
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 05/10] NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async()
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (3 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 04/10] NFS: Call readpage_async_filler() from nfs_readpage_async() Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 06/10] NFS: Allow internal use of read structs and functions Dave Wysochanski
` (5 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
Add nfs_pageio_complete_read() and call this from both nfs_readpage()
and nfs_readpages(), since the submission and accounting is the same
for both functions.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/fscache.c | 4 --
fs/nfs/read.c | 137 ++++++++++++++++++++++---------------------------
include/linux/nfs_fs.h | 1 -
3 files changed, 61 insertions(+), 81 deletions(-)
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index a60df88efc40..c4c021c6ebbd 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -390,10 +390,6 @@ static void nfs_readpage_from_fscache_complete(struct page *page,
if (!error) {
SetPageUptodate(page);
unlock_page(page);
- } else {
- error = nfs_readpage_async(context, page->mapping->host, page);
- if (error)
- unlock_page(page);
}
}
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 0ed79e6bc486..d2b6dce1f99f 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -74,6 +74,24 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
}
EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
+static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
+ struct inode *inode)
+{
+ struct nfs_pgio_mirror *pgm;
+ unsigned long npages;
+
+ nfs_pageio_complete(pgio);
+
+ /* It doesn't make sense to do mirrored reads! */
+ WARN_ON_ONCE(pgio->pg_mirror_count != 1);
+
+ pgm = &pgio->pg_mirrors[0];
+ NFS_I(inode)->read_io += pgm->pg_bytes_written;
+ npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ nfs_add_stats(inode, NFSIOS_READPAGES, npages);
+}
+
+
void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
{
struct nfs_pgio_mirror *mirror;
@@ -119,36 +137,6 @@ struct nfs_readdesc {
struct nfs_open_context *ctx;
};
-static int readpage_async_filler(void *data, struct page *page);
-
-int nfs_readpage_async(void *data, struct inode *inode,
- struct page *page)
-{
- struct nfs_readdesc *desc = data;
- struct nfs_pgio_mirror *pgm;
- int error;
-
- nfs_pageio_init_read(&desc->pgio, inode, false,
- &nfs_async_read_completion_ops);
-
- error = readpage_async_filler(desc, page);
- if (error)
- goto out;
-
- nfs_pageio_complete(&desc->pgio);
-
- /* It doesn't make sense to do mirrored reads! */
- WARN_ON_ONCE(desc->pgio.pg_mirror_count != 1);
-
- pgm = &desc->pgio.pg_mirrors[0];
- NFS_I(inode)->read_io += pgm->pg_bytes_written;
-
- return desc->pgio.pg_error < 0 ? desc->pgio.pg_error : 0;
-
-out:
- return error;
-}
-
static void nfs_page_group_set_uptodate(struct nfs_page *req)
{
if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
@@ -170,8 +158,7 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
/* note: regions of the page not covered by a
- * request are zeroed in nfs_readpage_async /
- * readpage_async_filler */
+ * request are zeroed in readpage_async_filler */
if (bytes > hdr->good_bytes) {
/* nothing in this request was good, so zero
* the full extent of the request */
@@ -303,6 +290,38 @@ static void nfs_readpage_result(struct rpc_task *task,
nfs_readpage_retry(task, hdr);
}
+static int
+readpage_async_filler(void *data, struct page *page)
+{
+ struct nfs_readdesc *desc = data;
+ struct nfs_page *new;
+ unsigned int len;
+ int error;
+
+ len = nfs_page_length(page);
+ if (len == 0)
+ return nfs_return_empty_page(page);
+
+ new = nfs_create_request(desc->ctx, page, 0, len);
+ if (IS_ERR(new))
+ goto out_error;
+
+ if (len < PAGE_SIZE)
+ zero_user_segment(page, len, PAGE_SIZE);
+ if (!nfs_pageio_add_request(&desc->pgio, new)) {
+ nfs_list_remove_request(new);
+ error = desc->pgio.pg_error;
+ nfs_readpage_release(new, error);
+ goto out;
+ }
+ return 0;
+out_error:
+ error = PTR_ERR(new);
+ unlock_page(page);
+out:
+ return error;
+}
+
/*
* Read a page over NFS.
* We read the page synchronously in the following case:
@@ -351,13 +370,20 @@ int nfs_readpage(struct file *file, struct page *page)
}
xchg(&desc.ctx->error, 0);
- ret = nfs_readpage_async(&desc, inode, page);
+ nfs_pageio_init_read(&desc.pgio, inode, false,
+ &nfs_async_read_completion_ops);
+
+ ret = readpage_async_filler(&desc, page);
+
+ if (!ret)
+ nfs_pageio_complete_read(&desc.pgio, inode);
+
+ ret = desc.pgio.pg_error < 0 ? desc.pgio.pg_error : 0;
if (!ret) {
ret = wait_on_page_locked_killable(page);
if (!PageUptodate(page) && !ret)
ret = xchg(&desc.ctx->error, 0);
}
- nfs_add_stats(inode, NFSIOS_READPAGES, 1);
out:
put_nfs_open_context(desc.ctx);
return ret;
@@ -366,45 +392,11 @@ int nfs_readpage(struct file *file, struct page *page)
return ret;
}
-static int
-readpage_async_filler(void *data, struct page *page)
-{
- struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
- struct nfs_page *new;
- unsigned int len;
- int error;
-
- len = nfs_page_length(page);
- if (len == 0)
- return nfs_return_empty_page(page);
-
- new = nfs_create_request(desc->ctx, page, 0, len);
- if (IS_ERR(new))
- goto out_error;
-
- if (len < PAGE_SIZE)
- zero_user_segment(page, len, PAGE_SIZE);
- if (!nfs_pageio_add_request(&desc->pgio, new)) {
- nfs_list_remove_request(new);
- error = desc->pgio.pg_error;
- nfs_readpage_release(new, error);
- goto out;
- }
- return 0;
-out_error:
- error = PTR_ERR(new);
- unlock_page(page);
-out:
- return error;
-}
-
int nfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
- struct nfs_pgio_mirror *pgm;
struct nfs_readdesc desc;
struct inode *inode = mapping->host;
- unsigned long npages;
int ret;
dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
@@ -437,16 +429,9 @@ int nfs_readpages(struct file *file, struct address_space *mapping,
&nfs_async_read_completion_ops);
ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
- nfs_pageio_complete(&desc.pgio);
- /* It doesn't make sense to do mirrored reads! */
- WARN_ON_ONCE(desc.pgio.pg_mirror_count != 1);
+ nfs_pageio_complete_read(&desc.pgio, inode);
- pgm = &desc.pgio.pg_mirrors[0];
- NFS_I(inode)->read_io += pgm->pg_bytes_written;
- npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >>
- PAGE_SHIFT;
- nfs_add_stats(inode, NFSIOS_READPAGES, npages);
read_complete:
put_nfs_open_context(desc.ctx);
out:
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index cb0248a34518..3cfcf219e96b 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -570,7 +570,6 @@ extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred, s
extern int nfs_readpage(struct file *, struct page *);
extern int nfs_readpages(struct file *, struct address_space *,
struct list_head *, unsigned);
-extern int nfs_readpage_async(void *, struct inode *, struct page *);
/*
* inline functions
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 06/10] NFS: Allow internal use of read structs and functions
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (4 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 05/10] NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async() Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-02-05 13:47 ` David Wysochanski
2021-01-28 14:55 ` [PATCH 07/10] NFS: Convert to the netfs API and nfs_readpage to use netfs_readpage Dave Wysochanski
` (4 subsequent siblings)
10 siblings, 1 reply; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
The conversion of the NFS read paths to the new fscache API
will require use of a few read structs and functions,
so move these declarations as required.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/internal.h | 8 ++++++++
fs/nfs/read.c | 13 ++++---------
2 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 62d3189745cd..8514d002c922 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -457,9 +457,17 @@ extern char *nfs_path(char **p, struct dentry *dentry,
struct nfs_pgio_completion_ops;
/* read.c */
+extern const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
struct inode *inode, bool force_mds,
const struct nfs_pgio_completion_ops *compl_ops);
+struct nfs_readdesc {
+ struct nfs_pageio_descriptor pgio;
+ struct nfs_open_context *ctx;
+};
+extern int readpage_async_filler(void *data, struct page *page);
+extern void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
+ struct inode *inode);
extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index d2b6dce1f99f..9618abf01136 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -30,7 +30,7 @@
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
-static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
+const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
static const struct nfs_rw_ops nfs_rw_read_ops;
static struct kmem_cache *nfs_rdata_cachep;
@@ -74,7 +74,7 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
}
EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
-static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
+void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
struct inode *inode)
{
struct nfs_pgio_mirror *pgm;
@@ -132,11 +132,6 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
nfs_release_request(req);
}
-struct nfs_readdesc {
- struct nfs_pageio_descriptor pgio;
- struct nfs_open_context *ctx;
-};
-
static void nfs_page_group_set_uptodate(struct nfs_page *req)
{
if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
@@ -215,7 +210,7 @@ static void nfs_initiate_read(struct nfs_pgio_header *hdr,
}
}
-static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
+const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
.error_cleanup = nfs_async_read_error,
.completion = nfs_read_completion,
};
@@ -290,7 +285,7 @@ static void nfs_readpage_result(struct rpc_task *task,
nfs_readpage_retry(task, hdr);
}
-static int
+int
readpage_async_filler(void *data, struct page *page)
{
struct nfs_readdesc *desc = data;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH 06/10] NFS: Allow internal use of read structs and functions
2021-01-28 14:55 ` [PATCH 06/10] NFS: Allow internal use of read structs and functions Dave Wysochanski
@ 2021-02-05 13:47 ` David Wysochanski
2021-02-05 16:24 ` Anna Schumaker
0 siblings, 1 reply; 16+ messages in thread
From: David Wysochanski @ 2021-02-05 13:47 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
On Thu, Jan 28, 2021 at 9:59 AM Dave Wysochanski <dwysocha@redhat.com> wrote:
>
> The conversion of the NFS read paths to the new fscache API
> will require use of a few read structs and functions,
> so move these declarations as required.
>
> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
> ---
> fs/nfs/internal.h | 8 ++++++++
> fs/nfs/read.c | 13 ++++---------
> 2 files changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 62d3189745cd..8514d002c922 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -457,9 +457,17 @@ extern char *nfs_path(char **p, struct dentry *dentry,
>
> struct nfs_pgio_completion_ops;
> /* read.c */
> +extern const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> struct inode *inode, bool force_mds,
> const struct nfs_pgio_completion_ops *compl_ops);
> +struct nfs_readdesc {
> + struct nfs_pageio_descriptor pgio;
> + struct nfs_open_context *ctx;
> +};
> +extern int readpage_async_filler(void *data, struct page *page);
> +extern void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
> + struct inode *inode);
> extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
> extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
>
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index d2b6dce1f99f..9618abf01136 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -30,7 +30,7 @@
>
> #define NFSDBG_FACILITY NFSDBG_PAGECACHE
>
> -static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> +const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> static const struct nfs_rw_ops nfs_rw_read_ops;
>
> static struct kmem_cache *nfs_rdata_cachep;
> @@ -74,7 +74,7 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> }
> EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
>
> -static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
> +void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
> struct inode *inode)
> {
> struct nfs_pgio_mirror *pgm;
> @@ -132,11 +132,6 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
> nfs_release_request(req);
> }
>
> -struct nfs_readdesc {
> - struct nfs_pageio_descriptor pgio;
> - struct nfs_open_context *ctx;
> -};
> -
> static void nfs_page_group_set_uptodate(struct nfs_page *req)
> {
> if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
> @@ -215,7 +210,7 @@ static void nfs_initiate_read(struct nfs_pgio_header *hdr,
> }
> }
>
> -static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
> +const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
> .error_cleanup = nfs_async_read_error,
> .completion = nfs_read_completion,
> };
> @@ -290,7 +285,7 @@ static void nfs_readpage_result(struct rpc_task *task,
> nfs_readpage_retry(task, hdr);
> }
>
> -static int
> +int
> readpage_async_filler(void *data, struct page *page)
> {
> struct nfs_readdesc *desc = data;
> --
> 1.8.3.1
>
Anna, FYI, you could drop this from your linux-next branch if you want.
Since the fscache conversion patches are not included, we don't really
need this patch.
The other patches 1-5 I are valid cleanups but this really goes with
the conversion patches.
It's your call though.
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 06/10] NFS: Allow internal use of read structs and functions
2021-02-05 13:47 ` David Wysochanski
@ 2021-02-05 16:24 ` Anna Schumaker
0 siblings, 0 replies; 16+ messages in thread
From: Anna Schumaker @ 2021-02-05 16:24 UTC (permalink / raw)
To: David Wysochanski; +Cc: Trond Myklebust, linux-nfs
On Fri, Feb 5, 2021 at 8:53 AM David Wysochanski <dwysocha@redhat.com> wrote:
>
> On Thu, Jan 28, 2021 at 9:59 AM Dave Wysochanski <dwysocha@redhat.com> wrote:
> >
> > The conversion of the NFS read paths to the new fscache API
> > will require use of a few read structs and functions,
> > so move these declarations as required.
> >
> > Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
> > ---
> > fs/nfs/internal.h | 8 ++++++++
> > fs/nfs/read.c | 13 ++++---------
> > 2 files changed, 12 insertions(+), 9 deletions(-)
> >
> > diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> > index 62d3189745cd..8514d002c922 100644
> > --- a/fs/nfs/internal.h
> > +++ b/fs/nfs/internal.h
> > @@ -457,9 +457,17 @@ extern char *nfs_path(char **p, struct dentry *dentry,
> >
> > struct nfs_pgio_completion_ops;
> > /* read.c */
> > +extern const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> > extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> > struct inode *inode, bool force_mds,
> > const struct nfs_pgio_completion_ops *compl_ops);
> > +struct nfs_readdesc {
> > + struct nfs_pageio_descriptor pgio;
> > + struct nfs_open_context *ctx;
> > +};
> > +extern int readpage_async_filler(void *data, struct page *page);
> > +extern void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
> > + struct inode *inode);
> > extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
> > extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
> >
> > diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> > index d2b6dce1f99f..9618abf01136 100644
> > --- a/fs/nfs/read.c
> > +++ b/fs/nfs/read.c
> > @@ -30,7 +30,7 @@
> >
> > #define NFSDBG_FACILITY NFSDBG_PAGECACHE
> >
> > -static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> > +const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
> > static const struct nfs_rw_ops nfs_rw_read_ops;
> >
> > static struct kmem_cache *nfs_rdata_cachep;
> > @@ -74,7 +74,7 @@ void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
> > }
> > EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
> >
> > -static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
> > +void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio,
> > struct inode *inode)
> > {
> > struct nfs_pgio_mirror *pgm;
> > @@ -132,11 +132,6 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
> > nfs_release_request(req);
> > }
> >
> > -struct nfs_readdesc {
> > - struct nfs_pageio_descriptor pgio;
> > - struct nfs_open_context *ctx;
> > -};
> > -
> > static void nfs_page_group_set_uptodate(struct nfs_page *req)
> > {
> > if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
> > @@ -215,7 +210,7 @@ static void nfs_initiate_read(struct nfs_pgio_header *hdr,
> > }
> > }
> >
> > -static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
> > +const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
> > .error_cleanup = nfs_async_read_error,
> > .completion = nfs_read_completion,
> > };
> > @@ -290,7 +285,7 @@ static void nfs_readpage_result(struct rpc_task *task,
> > nfs_readpage_retry(task, hdr);
> > }
> >
> > -static int
> > +int
> > readpage_async_filler(void *data, struct page *page)
> > {
> > struct nfs_readdesc *desc = data;
> > --
> > 1.8.3.1
> >
>
> Anna, FYI, you could drop this from your linux-next branch if you want.
> Since the fscache conversion patches are not included, we don't really
> need this patch.
> The other patches 1-5 I are valid cleanups but this really goes with
> the conversion patches.
> It's your call though.
Sounds good. I've dropped the patch from my tree.
Anna
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH 07/10] NFS: Convert to the netfs API and nfs_readpage to use netfs_readpage
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (5 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 06/10] NFS: Allow internal use of read structs and functions Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 08/10] NFS: Convert readpages to readahead and use netfs_readahead for fscache Dave Wysochanski
` (3 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
This patch converts the main NFS read paths to the new netfs API,
when fscache is enabled, and converts readpage while minimizing
changes to the existing NFS read code paths.
The netfs API requires a few functions to be provided by the
netfs:
- init_rreq: allows netfs to allocate resources prior to IO
- is_cache_enabled: allows netfs to disable fscache
- begin_cache_operation: signals the start of an fscache IO
- issue_op: called when netfs should issue read to server
- clamp_length: allows netfs to limit size of IO
- cleanup: allows netfs to cleanup after an IO is complete
The new netfs_readpage() API is called when fscache is enabled.
If a read cannot be satisfied from fscache, the netfs is called
back via issue_op() to obtain the data from the server. Once
the read completes, the netfs must call netfs_subreq_terminated()
which then may write the data to fscache. In order to call back
into fscache via netfs_subreq_terminated(), we must save the
netfs_read_subrequest* as a field in the nfs_pgio_header, similar
to nfs_direct_req.
If the netfs has a read IO limit (for example, NFS 'rsize' mount
options) the clamp_length() function is called.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/fscache.c | 158 ++++++++++++++++++++++++++++++++---------------
fs/nfs/fscache.h | 44 +++----------
fs/nfs/pagelist.c | 2 +
fs/nfs/read.c | 9 ++-
include/linux/nfs_page.h | 1 +
include/linux/nfs_xdr.h | 1 +
6 files changed, 127 insertions(+), 88 deletions(-)
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index c4c021c6ebbd..fede075209f5 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -15,6 +15,9 @@
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/iversion.h>
+#include <linux/xarray.h>
+#include <linux/fscache.h>
+#include <linux/netfs.h>
#include "internal.h"
#include "iostat.h"
@@ -373,62 +376,126 @@ void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
NFSIOS_FSCACHE_PAGES_UNCACHED);
}
-/*
- * Handle completion of a page being read from the cache.
- * - Called in process (keventd) context.
- */
-static void nfs_readpage_from_fscache_complete(struct page *page,
- void *context,
- int error)
+static void nfs_issue_op(struct netfs_read_subrequest *subreq)
{
- dfprintk(FSCACHE,
- "NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n",
- page, context, error);
-
- /* if the read completes with an error, we just unlock the page and let
- * the VM reissue the readpage */
- if (!error) {
- SetPageUptodate(page);
- unlock_page(page);
+ struct inode *inode = subreq->rreq->inode;
+ struct nfs_readdesc *desc = subreq->rreq->netfs_priv;
+ struct page *page;
+ pgoff_t start = (subreq->start + subreq->transferred) >> PAGE_SHIFT;
+ pgoff_t last = ((subreq->start + subreq->len -
+ subreq->transferred - 1) >> PAGE_SHIFT);
+ XA_STATE(xas, &subreq->rreq->mapping->i_pages, start);
+
+ dfprintk(FSCACHE, "NFS: %s(fsc:%p s:%lu l:%lu) subreq->start: %lld "
+ "subreq->len: %ld subreq->transferred: %ld\n",
+ __func__, nfs_i_fscache(inode), start, last, subreq->start,
+ subreq->len, subreq->transferred);
+
+ nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
+ last - start + 1);
+ nfs_pageio_init_read(&desc->pgio, inode, false,
+ &nfs_async_read_completion_ops);
+
+ desc->pgio.pg_fsc = subreq; /* used in completion */
+
+ rcu_read_lock();
+ xas_for_each(&xas, page, last) {
+ subreq->error = readpage_async_filler(desc, page);
+ if (subreq->error < 0)
+ break;
+ }
+ rcu_read_unlock();
+ nfs_pageio_complete_read(&desc->pgio, inode);
+}
+
+static bool nfs_clamp_length(struct netfs_read_subrequest *subreq)
+{
+ struct inode *inode = subreq->rreq->mapping->host;
+ unsigned int rsize = NFS_SB(inode->i_sb)->rsize;
+
+ if (subreq->len > rsize) {
+ dfprintk(FSCACHE,
+ "NFS: %s(fsc:%p slen:%lu rsize: %u)\n",
+ __func__, nfs_i_fscache(inode), subreq->len, rsize);
+ subreq->len = rsize;
}
+
+ return true;
+}
+
+static void nfs_cleanup(struct address_space *mapping, void *netfs_priv)
+{
+ ; /* fscache assumes if netfs_priv is given we have cleanup */
+}
+
+atomic_t nfs_fscache_debug_id;
+static void nfs_init_rreq(struct netfs_read_request *rreq, struct file *file)
+{
+ struct nfs_inode *nfsi = NFS_I(rreq->inode);
+
+ if (nfsi->fscache && test_bit(NFS_INO_FSCACHE, &nfsi->flags))
+ rreq->cookie_debug_id = atomic_inc_return(&nfs_fscache_debug_id);
+}
+
+static bool nfs_is_cache_enabled(struct inode *inode)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+
+ return nfsi->fscache && test_bit(NFS_INO_FSCACHE, &nfsi->flags);
+}
+
+static int nfs_begin_cache_operation(struct netfs_read_request *rreq)
+{
+ struct fscache_cookie *cookie = NFS_I(rreq->inode)->fscache;
+
+ return fscache_begin_read_operation(rreq, cookie);
}
+static struct netfs_read_request_ops nfs_fscache_req_ops = {
+ .init_rreq = nfs_init_rreq,
+ .is_cache_enabled = nfs_is_cache_enabled,
+ .begin_cache_operation = nfs_begin_cache_operation,
+ .issue_op = nfs_issue_op,
+ .clamp_length = nfs_clamp_length,
+ .cleanup = nfs_cleanup
+};
+
/*
* Retrieve a page from fscache
*/
-int __nfs_readpage_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode, struct page *page)
+int nfs_readpage_from_fscache(struct file *file,
+ struct page *page,
+ struct nfs_readdesc *desc)
{
int ret;
+ struct inode *inode = file_inode(file);
+
+ if (!NFS_I(file_inode(file))->fscache)
+ return -ENOBUFS;
dfprintk(FSCACHE,
"NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n",
nfs_i_fscache(inode), page, page->index, page->flags, inode);
- ret = fscache_read_or_alloc_page(nfs_i_fscache(inode),
- page,
- nfs_readpage_from_fscache_complete,
- ctx,
- GFP_KERNEL);
+ ret = netfs_readpage(file, page, &nfs_fscache_req_ops, desc);
switch (ret) {
- case 0: /* read BIO submitted (page in fscache) */
- dfprintk(FSCACHE,
- "NFS: readpage_from_fscache: BIO submitted\n");
+ case 0: /* read submitted */
+ dfprintk(FSCACHE, "NFS: readpage_from_fscache: submitted\n");
nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
return ret;
case -ENOBUFS: /* inode not in cache */
case -ENODATA: /* page not in cache */
nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
- dfprintk(FSCACHE,
- "NFS: readpage_from_fscache %d\n", ret);
+ dfprintk(FSCACHE, "NFS: readpage_from_fscache %d\n", ret);
return 1;
default:
dfprintk(FSCACHE, "NFS: readpage_from_fscache %d\n", ret);
nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
}
+
return ret;
}
@@ -449,7 +516,7 @@ int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
mapping, pages, nr_pages,
- nfs_readpage_from_fscache_complete,
+ NULL,
ctx,
mapping_gfp_mask(mapping));
if (*nr_pages < npages)
@@ -483,30 +550,19 @@ int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
}
/*
- * Store a newly fetched page in fscache
- * - PG_fscache must be set on the page
+ * Store a newly fetched data in fscache
*/
-void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
+void nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr,
+ unsigned long bytes)
{
- int ret;
+ struct netfs_read_subrequest *subreq = hdr->fsc;
- dfprintk(FSCACHE,
- "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n",
- nfs_i_fscache(inode), page, page->index, page->flags, sync);
-
- ret = fscache_write_page(nfs_i_fscache(inode), page,
- inode->i_size, GFP_KERNEL);
- dfprintk(FSCACHE,
- "NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n",
- page, page->index, page->flags, ret);
-
- if (ret != 0) {
- fscache_uncache_page(nfs_i_fscache(inode), page);
- nfs_inc_fscache_stats(inode,
- NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
- nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
- } else {
- nfs_inc_fscache_stats(inode,
- NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
+ if (NFS_I(hdr->inode)->fscache && subreq) {
+ dfprintk(FSCACHE,
+ "NFS: read_completion_to_fscache(fsc:%p err:%d bytes:%lu subreq->len:%lu\n",
+ NFS_I(hdr->inode)->fscache, hdr->error, bytes, subreq->len);
+ __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+ netfs_subreq_terminated(subreq, hdr->error ?: bytes);
+ hdr->fsc = NULL;
}
}
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 6754c8607230..858f28b1ce03 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -95,13 +95,14 @@ struct nfs_fscache_inode_auxdata {
extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
extern int nfs_fscache_release_page(struct page *, gfp_t);
-
-extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
- struct inode *, struct page *);
+extern int nfs_readpage_from_fscache(struct file *file,
+ struct page *page,
+ struct nfs_readdesc *desc);
extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
struct inode *, struct address_space *,
struct list_head *, unsigned *);
-extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
+extern void nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr,
+ unsigned long bytes);
/*
* wait for a page to complete writing to the cache
@@ -125,18 +126,6 @@ static inline void nfs_fscache_invalidate_page(struct page *page,
}
/*
- * Retrieve a page from an inode data storage object.
- */
-static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct page *page)
-{
- if (NFS_I(inode)->fscache)
- return __nfs_readpage_from_fscache(ctx, inode, page);
- return -ENOBUFS;
-}
-
-/*
* Retrieve a set of pages from an inode data storage object.
*/
static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
@@ -152,18 +141,6 @@ static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
}
/*
- * Store a page newly fetched from the server in an inode data storage object
- * in the cache.
- */
-static inline void nfs_readpage_to_fscache(struct inode *inode,
- struct page *page,
- int sync)
-{
- if (PageFsCache(page))
- __nfs_readpage_to_fscache(inode, page, sync);
-}
-
-/*
* Invalidate the contents of fscache for this inode. This will not sleep.
*/
static inline void nfs_fscache_invalidate(struct inode *inode)
@@ -212,9 +189,9 @@ static inline void nfs_fscache_invalidate_page(struct page *page,
static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
struct page *page) {}
-static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct page *page)
+static inline int nfs_readpage_from_fscache(struct file *file,
+ struct page *page,
+ struct nfs_readdesc *desc)
{
return -ENOBUFS;
}
@@ -226,9 +203,8 @@ static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
{
return -ENOBUFS;
}
-static inline void nfs_readpage_to_fscache(struct inode *inode,
- struct page *page, int sync) {}
-
+static inline void nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr,
+ unsigned long bytes) {}
static inline void nfs_fscache_invalidate(struct inode *inode) {}
static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 78c9c4bdef2b..2e21e6c4023a 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -68,6 +68,7 @@ void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
hdr->good_bytes = mirror->pg_count;
hdr->io_completion = desc->pg_io_completion;
hdr->dreq = desc->pg_dreq;
+ hdr->fsc = desc->pg_fsc;
hdr->release = release;
hdr->completion_ops = desc->pg_completion_ops;
if (hdr->completion_ops->init_hdr)
@@ -849,6 +850,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
desc->pg_lseg = NULL;
desc->pg_io_completion = NULL;
desc->pg_dreq = NULL;
+ desc->pg_fsc = NULL;
desc->pg_bsize = bsize;
desc->pg_mirror_count = 1;
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 9618abf01136..b47e4f38539b 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -124,10 +124,11 @@ static void nfs_readpage_release(struct nfs_page *req, int error)
struct address_space *mapping = page_file_mapping(page);
if (PageUptodate(page))
- nfs_readpage_to_fscache(inode, page, 0);
+ ; /* FIXME: review fscache page error handling */
else if (!PageError(page) && !PagePrivate(page))
generic_error_remove_page(mapping, page);
- unlock_page(page);
+ if (!nfs_i_fscache(inode))
+ unlock_page(page);
}
nfs_release_request(req);
}
@@ -181,6 +182,8 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
nfs_list_remove_request(req);
nfs_readpage_release(req, error);
}
+ /* FIXME: NFS_IOHDR_ERROR and NFS_IOHDR_EOF handled per-page */
+ nfs_read_completion_to_fscache(hdr, bytes);
out:
hdr->release(hdr);
}
@@ -359,7 +362,7 @@ int nfs_readpage(struct file *file, struct page *page)
desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
if (!IS_SYNC(inode)) {
- ret = nfs_readpage_from_fscache(desc.ctx, inode, page);
+ ret = nfs_readpage_from_fscache(file, page, &desc);
if (ret == 0)
goto out;
}
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index f0373a6cb5fb..b45570bcde91 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -101,6 +101,7 @@ struct nfs_pageio_descriptor {
struct pnfs_layout_segment *pg_lseg;
struct nfs_io_completion *pg_io_completion;
struct nfs_direct_req *pg_dreq;
+ void *pg_fsc;
unsigned int pg_bsize; /* default bsize for mirrors */
u32 pg_mirror_count;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 3327239fa2f9..95423d3d9d98 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1607,6 +1607,7 @@ struct nfs_pgio_header {
const struct nfs_rw_ops *rw_ops;
struct nfs_io_completion *io_completion;
struct nfs_direct_req *dreq;
+ void *fsc;
int pnfs_error;
int error; /* merge with pnfs_error */
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 08/10] NFS: Convert readpages to readahead and use netfs_readahead for fscache
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (6 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 07/10] NFS: Convert to the netfs API and nfs_readpage to use netfs_readpage Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 09/10] NFS: Update releasepage to handle new fscache kiocb IO API Dave Wysochanski
` (2 subsequent siblings)
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
The new FS-Cache API does not have a readpages equivalent function,
and instead of fscache_read_or_alloc_pages() it implements a readahead
function, netfs_readahead(). Call netfs_readahead() if fscache is
enabled, and note that netfs_readahead() has good tracing so we can
remove one dfprintk.
If fscache is not enabled, utilize readahead_page() to run through
the pages needed calling readpage_async_filler(). If we get an error
on any page, then exit the loop, which matches the behavior of
previously called read_cache_pages() when 'filler' returns an error.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/file.c | 2 +-
fs/nfs/fscache.c | 49 +++++++---------------------------------------
fs/nfs/fscache.h | 28 ++++----------------------
fs/nfs/read.c | 36 +++++++++++++++++-----------------
include/linux/nfs_fs.h | 3 +--
include/linux/nfs_iostat.h | 2 +-
6 files changed, 32 insertions(+), 88 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 63940a7a70be..ebcaa164db5f 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -515,7 +515,7 @@ static void nfs_swap_deactivate(struct file *file)
const struct address_space_operations nfs_file_aops = {
.readpage = nfs_readpage,
- .readpages = nfs_readpages,
+ .readahead = nfs_readahead,
.set_page_dirty = __set_page_dirty_nobuffers,
.writepage = nfs_writepage,
.writepages = nfs_writepages,
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index fede075209f5..2ff631da62ec 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -502,51 +502,16 @@ int nfs_readpage_from_fscache(struct file *file,
/*
* Retrieve a set of pages from fscache
*/
-int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned *nr_pages)
+int nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *ractl)
{
- unsigned npages = *nr_pages;
- int ret;
-
- dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n",
- nfs_i_fscache(inode), npages, inode);
-
- ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
- mapping, pages, nr_pages,
- NULL,
- ctx,
- mapping_gfp_mask(mapping));
- if (*nr_pages < npages)
- nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK,
- npages);
- if (*nr_pages > 0)
- nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
- *nr_pages);
-
- switch (ret) {
- case 0: /* read submitted to the cache for all pages */
- BUG_ON(!list_empty(pages));
- BUG_ON(*nr_pages != 0);
- dfprintk(FSCACHE,
- "NFS: nfs_getpages_from_fscache: submitted\n");
-
- return ret;
-
- case -ENOBUFS: /* some pages aren't cached and can't be */
- case -ENODATA: /* some pages aren't cached */
- dfprintk(FSCACHE,
- "NFS: nfs_getpages_from_fscache: no page: %d\n", ret);
- return 1;
+ if (!NFS_I(ractl->mapping->host)->fscache)
+ return -ENOBUFS;
- default:
- dfprintk(FSCACHE,
- "NFS: nfs_getpages_from_fscache: ret %d\n", ret);
- }
+ netfs_readahead(ractl, &nfs_fscache_req_ops, desc);
- return ret;
+ /* FIXME: NFSIOS_NFSIOS_FSCACHE_ stats */
+ return 0;
}
/*
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 858f28b1ce03..faccf4549d55 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -98,12 +98,10 @@ struct nfs_fscache_inode_auxdata {
extern int nfs_readpage_from_fscache(struct file *file,
struct page *page,
struct nfs_readdesc *desc);
-extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
- struct inode *, struct address_space *,
- struct list_head *, unsigned *);
+extern int nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *ractl);
extern void nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr,
unsigned long bytes);
-
/*
* wait for a page to complete writing to the cache
*/
@@ -126,21 +124,6 @@ static inline void nfs_fscache_invalidate_page(struct page *page,
}
/*
- * Retrieve a set of pages from an inode data storage object.
- */
-static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned *nr_pages)
-{
- if (NFS_I(inode)->fscache)
- return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
- nr_pages);
- return -ENOBUFS;
-}
-
-/*
* Invalidate the contents of fscache for this inode. This will not sleep.
*/
static inline void nfs_fscache_invalidate(struct inode *inode)
@@ -195,11 +178,8 @@ static inline int nfs_readpage_from_fscache(struct file *file,
{
return -ENOBUFS;
}
-static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
- struct inode *inode,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned *nr_pages)
+static inline int nfs_readahead_from_fscache(struct nfs_readdesc *desc,
+ struct readahead_control *ractl)
{
return -ENOBUFS;
}
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index b47e4f38539b..8be4f179a371 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -390,50 +390,50 @@ int nfs_readpage(struct file *file, struct page *page)
return ret;
}
-int nfs_readpages(struct file *file, struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
+void nfs_readahead(struct readahead_control *ractl)
{
struct nfs_readdesc desc;
- struct inode *inode = mapping->host;
+ struct inode *inode = ractl->mapping->host;
+ struct page *page;
int ret;
- dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
- inode->i_sb->s_id,
- (unsigned long long)NFS_FILEID(inode),
- nr_pages);
+ dprintk("NFS: %s (%s/%llu %lld)\n", __func__,
+ inode->i_sb->s_id,
+ (unsigned long long)NFS_FILEID(inode),
+ readahead_length(ractl));
nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
- ret = -ESTALE;
if (NFS_STALE(inode))
- goto out;
+ return;
- if (file == NULL) {
- ret = -EBADF;
+ if (ractl->file == NULL) {
desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (desc.ctx == NULL)
- goto out;
+ return;
} else
- desc.ctx = get_nfs_open_context(nfs_file_open_context(file));
+ desc.ctx = get_nfs_open_context(nfs_file_open_context(ractl->file));
/* attempt to read as many of the pages as possible from the cache
* - this returns -ENOBUFS immediately if the cookie is negative
*/
- ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
- pages, &nr_pages);
+ ret = nfs_readahead_from_fscache(&desc, ractl);
if (ret == 0)
goto read_complete; /* all pages were read */
nfs_pageio_init_read(&desc.pgio, inode, false,
&nfs_async_read_completion_ops);
- ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
+ while ((page = readahead_page(ractl))) {
+ ret = readpage_async_filler(&desc, page);
+ put_page(page);
+ if (unlikely(ret))
+ break;
+ }
nfs_pageio_complete_read(&desc.pgio, inode);
read_complete:
put_nfs_open_context(desc.ctx);
-out:
- return ret;
}
int __init nfs_init_readpagecache(void)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 3cfcf219e96b..968c79b1b09b 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -568,8 +568,7 @@ extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred, s
* linux/fs/nfs/read.c
*/
extern int nfs_readpage(struct file *, struct page *);
-extern int nfs_readpages(struct file *, struct address_space *,
- struct list_head *, unsigned);
+extern void nfs_readahead(struct readahead_control *rac);
/*
* inline functions
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 027874c36c88..8baf8fb7551d 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -53,7 +53,7 @@
* NFS page counters
*
* These count the number of pages read or written via nfs_readpage(),
- * nfs_readpages(), or their write equivalents.
+ * nfs_readahead(), or their write equivalents.
*
* NB: When adding new byte counters, please include the measured
* units in the name of each byte counter to help users of this
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 09/10] NFS: Update releasepage to handle new fscache kiocb IO API
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (7 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 08/10] NFS: Convert readpages to readahead and use netfs_readahead for fscache Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-01-28 14:55 ` [PATCH 10/10] NFS: update various invalidation code paths for new " Dave Wysochanski
2021-02-01 2:15 ` [PATCH 00/10] Convert NFS fscache read paths to netfs API David Wysochanski
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
When using the new fscache kiocb IO API, netfs callers should
no longer use fscache_maybe_release_page() in releasepage, but
instead should just wait PG_fscache as needed. The PG_fscache
page bit now means the page is being written to the cache.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/file.c | 11 +++++++++--
fs/nfs/fscache.c | 24 ------------------------
fs/nfs/fscache.h | 5 -----
fs/nfs/write.c | 10 ++++------
4 files changed, 13 insertions(+), 37 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index ebcaa164db5f..9e41745c3faf 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -431,8 +431,15 @@ static int nfs_release_page(struct page *page, gfp_t gfp)
/* If PagePrivate() is set, then the page is not freeable */
if (PagePrivate(page))
- return 0;
- return nfs_fscache_release_page(page, gfp);
+ return false;
+
+ if (PageFsCache(page)) {
+ if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS))
+ return false;
+ wait_on_page_fscache(page);
+ }
+
+ return true;
}
static void nfs_check_dirty_writeback(struct page *page,
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index 2ff631da62ec..dd8cf3cfed0a 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -332,30 +332,6 @@ void nfs_fscache_open_file(struct inode *inode, struct file *filp)
EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
/*
- * Release the caching state associated with a page, if the page isn't busy
- * interacting with the cache.
- * - Returns true (can release page) or false (page busy).
- */
-int nfs_fscache_release_page(struct page *page, gfp_t gfp)
-{
- if (PageFsCache(page)) {
- struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host);
-
- BUG_ON(!cookie);
- dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n",
- cookie, page, NFS_I(page->mapping->host));
-
- if (!fscache_maybe_release_page(cookie, page, gfp))
- return 0;
-
- nfs_inc_fscache_stats(page->mapping->host,
- NFSIOS_FSCACHE_PAGES_UNCACHED);
- }
-
- return 1;
-}
-
-/*
* Release the caching state associated with a page if undergoing complete page
* invalidation.
*/
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index faccf4549d55..9f8b1f8e69f3 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -94,7 +94,6 @@ struct nfs_fscache_inode_auxdata {
extern void nfs_fscache_open_file(struct inode *, struct file *);
extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
-extern int nfs_fscache_release_page(struct page *, gfp_t);
extern int nfs_readpage_from_fscache(struct file *file,
struct page *page,
struct nfs_readdesc *desc);
@@ -163,10 +162,6 @@ static inline void nfs_fscache_clear_inode(struct inode *inode) {}
static inline void nfs_fscache_open_file(struct inode *inode,
struct file *filp) {}
-static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
-{
- return 1; /* True: may release page */
-}
static inline void nfs_fscache_invalidate_page(struct page *page,
struct inode *inode) {}
static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 639c34fec04a..156508fb6730 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -2102,17 +2102,15 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
struct page *page, enum migrate_mode mode)
{
/*
- * If PagePrivate is set, then the page is currently associated with
- * an in-progress read or write request. Don't try to migrate it.
+ * If PagePrivate or PageFsCache is set, then the page is currently
+ * associated with an in-progress read or write request. Don't try
+ * to migrate it.
*
* FIXME: we could do this in principle, but we'll need a way to ensure
* that we can safely release the inode reference while holding
* the page lock.
*/
- if (PagePrivate(page))
- return -EBUSY;
-
- if (!nfs_fscache_release_page(page, GFP_KERNEL))
+ if (PagePrivate(page) || PageFsCache(page))
return -EBUSY;
return migrate_page(mapping, newpage, page, mode);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH 10/10] NFS: update various invalidation code paths for new IO API
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (8 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 09/10] NFS: Update releasepage to handle new fscache kiocb IO API Dave Wysochanski
@ 2021-01-28 14:55 ` Dave Wysochanski
2021-02-01 2:15 ` [PATCH 00/10] Convert NFS fscache read paths to netfs API David Wysochanski
10 siblings, 0 replies; 16+ messages in thread
From: Dave Wysochanski @ 2021-01-28 14:55 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
The new fscache IO API removes the following invalidation related
older APIs: fscache_uncache_all_inode_pages, fscache_uncache_page,
and fscache_wait_on_page_write. Update various code paths to the
new API which only requires we wait for PG_fscache which indicates
fscache IO in progress on the page.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
---
fs/nfs/file.c | 9 +++++----
fs/nfs/fscache.c | 23 +----------------------
fs/nfs/fscache.h | 28 +---------------------------
3 files changed, 7 insertions(+), 53 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 9e41745c3faf..e81e11603b9a 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -416,7 +416,7 @@ static void nfs_invalidate_page(struct page *page, unsigned int offset,
/* Cancel any unstarted writes on this page */
nfs_wb_page_cancel(page_file_mapping(page)->host, page);
- nfs_fscache_invalidate_page(page, page->mapping->host);
+ wait_on_page_fscache(page);
}
/*
@@ -482,12 +482,11 @@ static void nfs_check_dirty_writeback(struct page *page,
static int nfs_launder_page(struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
- struct nfs_inode *nfsi = NFS_I(inode);
dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
inode->i_ino, (long long)page_offset(page));
- nfs_fscache_wait_on_page_write(nfsi, page);
+ wait_on_page_fscache(page);
return nfs_wb_page(inode, page);
}
@@ -562,7 +561,9 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
sb_start_pagefault(inode->i_sb);
/* make sure the cache has finished storing the page */
- nfs_fscache_wait_on_page_write(NFS_I(inode), page);
+ if (PageFsCache(vmf->page) &&
+ wait_on_page_bit_killable(vmf->page, PG_fscache) < 0)
+ return VM_FAULT_RETRY;
wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING,
nfs_wait_bit_killable, TASK_KILLABLE);
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index dd8cf3cfed0a..d18eeea9c1b5 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -16,6 +16,7 @@
#include <linux/slab.h>
#include <linux/iversion.h>
#include <linux/xarray.h>
+#define FSCACHE_USE_NEW_IO_API
#include <linux/fscache.h>
#include <linux/netfs.h>
@@ -320,7 +321,6 @@ void nfs_fscache_open_file(struct inode *inode, struct file *filp)
dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);
clear_bit(NFS_INO_FSCACHE, &nfsi->flags);
fscache_disable_cookie(cookie, &auxdata, true);
- fscache_uncache_all_inode_pages(cookie, inode);
} else {
dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi);
fscache_enable_cookie(cookie, &auxdata, nfsi->vfs_inode.i_size,
@@ -331,27 +331,6 @@ void nfs_fscache_open_file(struct inode *inode, struct file *filp)
}
EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
-/*
- * Release the caching state associated with a page if undergoing complete page
- * invalidation.
- */
-void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
-{
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
-
- BUG_ON(!cookie);
-
- dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n",
- cookie, page, NFS_I(inode));
-
- fscache_wait_on_page_write(cookie, page);
-
- BUG_ON(!PageLocked(page));
- fscache_uncache_page(cookie, page);
- nfs_inc_fscache_stats(page->mapping->host,
- NFSIOS_FSCACHE_PAGES_UNCACHED);
-}
-
static void nfs_issue_op(struct netfs_read_subrequest *subreq)
{
struct inode *inode = subreq->rreq->inode;
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 9f8b1f8e69f3..f9d0464188af 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -11,6 +11,7 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/nfs4_mount.h>
+#define FSCACHE_USE_NEW_IO_API
#include <linux/fscache.h>
#ifdef CONFIG_NFS_FSCACHE
@@ -93,7 +94,6 @@ struct nfs_fscache_inode_auxdata {
extern void nfs_fscache_clear_inode(struct inode *);
extern void nfs_fscache_open_file(struct inode *, struct file *);
-extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
extern int nfs_readpage_from_fscache(struct file *file,
struct page *page,
struct nfs_readdesc *desc);
@@ -102,27 +102,6 @@ extern int nfs_readahead_from_fscache(struct nfs_readdesc *desc,
extern void nfs_read_completion_to_fscache(struct nfs_pgio_header *hdr,
unsigned long bytes);
/*
- * wait for a page to complete writing to the cache
- */
-static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
- struct page *page)
-{
- if (PageFsCache(page))
- fscache_wait_on_page_write(nfsi->fscache, page);
-}
-
-/*
- * release the caching state associated with a page if undergoing complete page
- * invalidation
- */
-static inline void nfs_fscache_invalidate_page(struct page *page,
- struct inode *inode)
-{
- if (PageFsCache(page))
- __nfs_fscache_invalidate_page(page, inode);
-}
-
-/*
* Invalidate the contents of fscache for this inode. This will not sleep.
*/
static inline void nfs_fscache_invalidate(struct inode *inode)
@@ -162,11 +141,6 @@ static inline void nfs_fscache_clear_inode(struct inode *inode) {}
static inline void nfs_fscache_open_file(struct inode *inode,
struct file *filp) {}
-static inline void nfs_fscache_invalidate_page(struct page *page,
- struct inode *inode) {}
-static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
- struct page *page) {}
-
static inline int nfs_readpage_from_fscache(struct file *file,
struct page *page,
struct nfs_readdesc *desc)
--
1.8.3.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH 00/10] Convert NFS fscache read paths to netfs API
2021-01-28 14:54 [PATCH 00/10] Convert NFS fscache read paths to netfs API Dave Wysochanski
` (9 preceding siblings ...)
2021-01-28 14:55 ` [PATCH 10/10] NFS: update various invalidation code paths for new " Dave Wysochanski
@ 2021-02-01 2:15 ` David Wysochanski
2021-02-01 14:30 ` Anna Schumaker
10 siblings, 1 reply; 16+ messages in thread
From: David Wysochanski @ 2021-02-01 2:15 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
On Thu, Jan 28, 2021 at 9:59 AM Dave Wysochanski <dwysocha@redhat.com> wrote:
>
> This minimal set of patches update the NFS client to use the new
> readahead method, and convert the NFS fscache to use the new netfs
> IO API, and are at:
> https://github.com/DaveWysochanskiRH/kernel/releases/tag/fscache-iter-lib-nfs-20210128
> https://github.com/DaveWysochanskiRH/kernel/commit/74357eb291c9c292f3ab3bc9ed1227cb76f52c51
>
> The patches are based on David Howells fscache-netfs-lib tree at
> https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=fscache-netfs-lib
>
> The first 6 patches refactor some of the NFS read code to facilitate
> re-use, the next 4 patches do the conversion to the new API. Note
> patch 8 converts nfs_readpages to nfs_readahead.
>
> Changes since my last posting on Jan 27, 2021
> - Fix oops with fscache enabled on parallel read unit test
> - Add patches to handle invalidate and releasepage
> - Use #define FSCACHE_USE_NEW_IO_API to select the new API
> - Minor cleanup in nfs_readahead_from_fscache
>
> Still TODO
> 1. Fix known bugs
> a) nfs_issue_op: takes rcu_read_lock but may calls nfs_page_alloc()
> with GFP_KERNEL which may sleep (dhowells noted this in a review)
> b) nfs_refresh_inode() takes inode->i_lock but may call
> __fscache_invalidate() which may sleep (found with lockdep)
> c) WARN with xfstest fscache/netapp/pnfs/nfs41
Turns out this is a bit more involved and I would not consider pNFS +
fscache stable right now.
For now I may have to disable fscache if pNFS is enabled unless I can
quickly come up
with a reasonable fix for the problem.
The problem is as follows. Once netfs calls us in "issue_op" for a
given subrequest, it expects
one call back when the subrequest completes. Now the "clamp_length"
function was developed
so we tell the netfs caller how big of an IO we can handle. However,
right now it only implements
an 'rsize' check, and it does not take into account pNFS
characteristics such as segments
which may split up the IO into multiple RPCs. Since each of the RPC
have their own
completion, and so far I've not come up with a way to just call back
into netfs when the
last one is done, I am not sure what the right approach is. One
obvious approach would be
a more sophisticated "clamp_length" function which adds similar logic
as to the *pg_test()
functions. But I don't want to duplicate that and so it's not really clear.
> 2. Fixup NFS fscache stats (NFSIOS_FSCACHE_*)
> * Compare with netfs stats and determine if still needed
> 3. Cleanup dfprintks and/or convert to tracepoints
> 4. Further tests (see "Not tested yet")
>
> Tests run
> 1. Custom NFS+fscache unit tests for basic operation: PASS
> * vers=3,4.0,4.1,4.2,sec=sys,server=localhost (same kernel)
> 2. cthon04: PASS
> * test options "-b -g -s -l", fsc,vers=3,4.0,4.1,4.2,sec=sys
> * No failures, oopses or hangs
> 3. iozone tests: PASS
> * nofsc,fsc,vers=3,4.0,4.1,4.2,sec=sys,server=rhel7,rhel8
> * No failures, oopses, or hangs
> 4. xfstests/generic: PASS*
> * no hangs or crashes (one WARN); failures unrelated to these patches
> * Ran following configurations
> * vers=4.1,fsc,sec=sys,rhel7-server: PASS
> * vers=4.0,fsc,sec=sys,rhel7-server: PASS
> * vers=3,fsc,sec=sys,rhel7-server: PASS
> * vers=4.1,nofsc,sec=sys,netapp-server(pnfs/files): PASS
> * vers=4.1,fsc,sec=sys,netapp-server(pnfs/files): INCOMPLETE
> * WARN_ON fs/netfs/read_helper.c:616
> * ran with kernel.panic_on_oops=1
> * vers=4.2,fsc,sec=sys,rhel7-server: running at generic/438
> * vers=4.2,fsc,sec=sys,rhel8-server: running at generic/127
> 5. kernel build: PASS
> * vers=4.2,fsc,sec=sys,rhel8-server: PASS
>
> Not tested yet:
> * error injections (for example, connection disruptions, server errors during IO, etc)
> * many process mixed read/write on same file
> * performance
>
> Dave Wysochanski (10):
> NFS: Clean up nfs_readpage() and nfs_readpages()
> NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read
> succeeds
> NFS: Refactor nfs_readpage() and nfs_readpage_async() to use
> nfs_readdesc
> NFS: Call readpage_async_filler() from nfs_readpage_async()
> NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async()
> NFS: Allow internal use of read structs and functions
> NFS: Convert to the netfs API and nfs_readpage to use netfs_readpage
> NFS: Convert readpages to readahead and use netfs_readahead for
> fscache
> NFS: Update releasepage to handle new fscache kiocb IO API
> NFS: update various invalidation code paths for new IO API
>
> fs/nfs/file.c | 22 +++--
> fs/nfs/fscache.c | 230 +++++++++++++++++++------------------------
> fs/nfs/fscache.h | 105 +++-----------------
> fs/nfs/internal.h | 8 ++
> fs/nfs/pagelist.c | 2 +
> fs/nfs/read.c | 240 ++++++++++++++++++++-------------------------
> fs/nfs/write.c | 10 +-
> include/linux/nfs_fs.h | 5 +-
> include/linux/nfs_iostat.h | 2 +-
> include/linux/nfs_page.h | 1 +
> include/linux/nfs_xdr.h | 1 +
> 11 files changed, 257 insertions(+), 369 deletions(-)
>
> --
> 1.8.3.1
>
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH 00/10] Convert NFS fscache read paths to netfs API
2021-02-01 2:15 ` [PATCH 00/10] Convert NFS fscache read paths to netfs API David Wysochanski
@ 2021-02-01 14:30 ` Anna Schumaker
2021-02-02 12:19 ` David Wysochanski
0 siblings, 1 reply; 16+ messages in thread
From: Anna Schumaker @ 2021-02-01 14:30 UTC (permalink / raw)
To: David Wysochanski; +Cc: Trond Myklebust, linux-nfs
Hi David,
On Sun, Jan 31, 2021 at 9:20 PM David Wysochanski <dwysocha@redhat.com> wrote:
>
> On Thu, Jan 28, 2021 at 9:59 AM Dave Wysochanski <dwysocha@redhat.com> wrote:
> >
> > This minimal set of patches update the NFS client to use the new
> > readahead method, and convert the NFS fscache to use the new netfs
> > IO API, and are at:
> > https://github.com/DaveWysochanskiRH/kernel/releases/tag/fscache-iter-lib-nfs-20210128
> > https://github.com/DaveWysochanskiRH/kernel/commit/74357eb291c9c292f3ab3bc9ed1227cb76f52c51
> >
> > The patches are based on David Howells fscache-netfs-lib tree at
> > https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=fscache-netfs-lib
> >
> > The first 6 patches refactor some of the NFS read code to facilitate
> > re-use, the next 4 patches do the conversion to the new API. Note
> > patch 8 converts nfs_readpages to nfs_readahead.
> >
> > Changes since my last posting on Jan 27, 2021
> > - Fix oops with fscache enabled on parallel read unit test
> > - Add patches to handle invalidate and releasepage
> > - Use #define FSCACHE_USE_NEW_IO_API to select the new API
> > - Minor cleanup in nfs_readahead_from_fscache
> >
> > Still TODO
> > 1. Fix known bugs
> > a) nfs_issue_op: takes rcu_read_lock but may calls nfs_page_alloc()
> > with GFP_KERNEL which may sleep (dhowells noted this in a review)
> > b) nfs_refresh_inode() takes inode->i_lock but may call
> > __fscache_invalidate() which may sleep (found with lockdep)
> > c) WARN with xfstest fscache/netapp/pnfs/nfs41
>
> Turns out this is a bit more involved and I would not consider pNFS +
> fscache stable right now.
> For now I may have to disable fscache if pNFS is enabled unless I can
> quickly come up
> with a reasonable fix for the problem.
So my thought right now is to take the first 6 cleanup / preparation
patches for the 5.12 merge window and save the cutover for 5.13. This
would give you an extra release cycle to fix the pNFS stability, and
it would give more time to find and fix any issues in netfs before
switching NFS over to it.
Would that work?
Anna
>
> The problem is as follows. Once netfs calls us in "issue_op" for a
> given subrequest, it expects
> one call back when the subrequest completes. Now the "clamp_length"
> function was developed
> so we tell the netfs caller how big of an IO we can handle. However,
> right now it only implements
> an 'rsize' check, and it does not take into account pNFS
> characteristics such as segments
> which may split up the IO into multiple RPCs. Since each of the RPC
> have their own
> completion, and so far I've not come up with a way to just call back
> into netfs when the
> last one is done, I am not sure what the right approach is. One
> obvious approach would be
> a more sophisticated "clamp_length" function which adds similar logic
> as to the *pg_test()
> functions. But I don't want to duplicate that and so it's not really clear.
>
> > 2. Fixup NFS fscache stats (NFSIOS_FSCACHE_*)
> > * Compare with netfs stats and determine if still needed
> > 3. Cleanup dfprintks and/or convert to tracepoints
> > 4. Further tests (see "Not tested yet")
> >
> > Tests run
> > 1. Custom NFS+fscache unit tests for basic operation: PASS
> > * vers=3,4.0,4.1,4.2,sec=sys,server=localhost (same kernel)
> > 2. cthon04: PASS
> > * test options "-b -g -s -l", fsc,vers=3,4.0,4.1,4.2,sec=sys
> > * No failures, oopses or hangs
> > 3. iozone tests: PASS
> > * nofsc,fsc,vers=3,4.0,4.1,4.2,sec=sys,server=rhel7,rhel8
> > * No failures, oopses, or hangs
> > 4. xfstests/generic: PASS*
> > * no hangs or crashes (one WARN); failures unrelated to these patches
> > * Ran following configurations
> > * vers=4.1,fsc,sec=sys,rhel7-server: PASS
> > * vers=4.0,fsc,sec=sys,rhel7-server: PASS
> > * vers=3,fsc,sec=sys,rhel7-server: PASS
> > * vers=4.1,nofsc,sec=sys,netapp-server(pnfs/files): PASS
> > * vers=4.1,fsc,sec=sys,netapp-server(pnfs/files): INCOMPLETE
> > * WARN_ON fs/netfs/read_helper.c:616
> > * ran with kernel.panic_on_oops=1
> > * vers=4.2,fsc,sec=sys,rhel7-server: running at generic/438
> > * vers=4.2,fsc,sec=sys,rhel8-server: running at generic/127
> > 5. kernel build: PASS
> > * vers=4.2,fsc,sec=sys,rhel8-server: PASS
> >
> > Not tested yet:
> > * error injections (for example, connection disruptions, server errors during IO, etc)
> > * many process mixed read/write on same file
> > * performance
> >
> > Dave Wysochanski (10):
> > NFS: Clean up nfs_readpage() and nfs_readpages()
> > NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read
> > succeeds
> > NFS: Refactor nfs_readpage() and nfs_readpage_async() to use
> > nfs_readdesc
> > NFS: Call readpage_async_filler() from nfs_readpage_async()
> > NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async()
> > NFS: Allow internal use of read structs and functions
> > NFS: Convert to the netfs API and nfs_readpage to use netfs_readpage
> > NFS: Convert readpages to readahead and use netfs_readahead for
> > fscache
> > NFS: Update releasepage to handle new fscache kiocb IO API
> > NFS: update various invalidation code paths for new IO API
> >
> > fs/nfs/file.c | 22 +++--
> > fs/nfs/fscache.c | 230 +++++++++++++++++++------------------------
> > fs/nfs/fscache.h | 105 +++-----------------
> > fs/nfs/internal.h | 8 ++
> > fs/nfs/pagelist.c | 2 +
> > fs/nfs/read.c | 240 ++++++++++++++++++++-------------------------
> > fs/nfs/write.c | 10 +-
> > include/linux/nfs_fs.h | 5 +-
> > include/linux/nfs_iostat.h | 2 +-
> > include/linux/nfs_page.h | 1 +
> > include/linux/nfs_xdr.h | 1 +
> > 11 files changed, 257 insertions(+), 369 deletions(-)
> >
> > --
> > 1.8.3.1
> >
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 00/10] Convert NFS fscache read paths to netfs API
2021-02-01 14:30 ` Anna Schumaker
@ 2021-02-02 12:19 ` David Wysochanski
0 siblings, 0 replies; 16+ messages in thread
From: David Wysochanski @ 2021-02-02 12:19 UTC (permalink / raw)
To: Anna Schumaker; +Cc: Trond Myklebust, linux-nfs
On Mon, Feb 1, 2021 at 9:30 AM Anna Schumaker <anna.schumaker@netapp.com> wrote:
>
> Hi David,
>
> On Sun, Jan 31, 2021 at 9:20 PM David Wysochanski <dwysocha@redhat.com> wrote:
> >
> > On Thu, Jan 28, 2021 at 9:59 AM Dave Wysochanski <dwysocha@redhat.com> wrote:
> > >
> > > This minimal set of patches update the NFS client to use the new
> > > readahead method, and convert the NFS fscache to use the new netfs
> > > IO API, and are at:
> > > https://github.com/DaveWysochanskiRH/kernel/releases/tag/fscache-iter-lib-nfs-20210128
> > > https://github.com/DaveWysochanskiRH/kernel/commit/74357eb291c9c292f3ab3bc9ed1227cb76f52c51
> > >
> > > The patches are based on David Howells fscache-netfs-lib tree at
> > > https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=fscache-netfs-lib
> > >
> > > The first 6 patches refactor some of the NFS read code to facilitate
> > > re-use, the next 4 patches do the conversion to the new API. Note
> > > patch 8 converts nfs_readpages to nfs_readahead.
> > >
> > > Changes since my last posting on Jan 27, 2021
> > > - Fix oops with fscache enabled on parallel read unit test
> > > - Add patches to handle invalidate and releasepage
> > > - Use #define FSCACHE_USE_NEW_IO_API to select the new API
> > > - Minor cleanup in nfs_readahead_from_fscache
> > >
> > > Still TODO
> > > 1. Fix known bugs
> > > a) nfs_issue_op: takes rcu_read_lock but may calls nfs_page_alloc()
> > > with GFP_KERNEL which may sleep (dhowells noted this in a review)
> > > b) nfs_refresh_inode() takes inode->i_lock but may call
> > > __fscache_invalidate() which may sleep (found with lockdep)
> > > c) WARN with xfstest fscache/netapp/pnfs/nfs41
> >
> > Turns out this is a bit more involved and I would not consider pNFS +
> > fscache stable right now.
> > For now I may have to disable fscache if pNFS is enabled unless I can
> > quickly come up
> > with a reasonable fix for the problem.
>
> So my thought right now is to take the first 6 cleanup / preparation
> patches for the 5.12 merge window and save the cutover for 5.13. This
> would give you an extra release cycle to fix the pNFS stability, and
> it would give more time to find and fix any issues in netfs before
> switching NFS over to it.
>
> Would that work?
> Anna
>
Yes that's fine.
> >
> > The problem is as follows. Once netfs calls us in "issue_op" for a
> > given subrequest, it expects
> > one call back when the subrequest completes. Now the "clamp_length"
> > function was developed
> > so we tell the netfs caller how big of an IO we can handle. However,
> > right now it only implements
> > an 'rsize' check, and it does not take into account pNFS
> > characteristics such as segments
> > which may split up the IO into multiple RPCs. Since each of the RPC
> > have their own
> > completion, and so far I've not come up with a way to just call back
> > into netfs when the
> > last one is done, I am not sure what the right approach is. One
> > obvious approach would be
> > a more sophisticated "clamp_length" function which adds similar logic
> > as to the *pg_test()
> > functions. But I don't want to duplicate that and so it's not really clear.
> >
> > > 2. Fixup NFS fscache stats (NFSIOS_FSCACHE_*)
> > > * Compare with netfs stats and determine if still needed
> > > 3. Cleanup dfprintks and/or convert to tracepoints
> > > 4. Further tests (see "Not tested yet")
> > >
> > > Tests run
> > > 1. Custom NFS+fscache unit tests for basic operation: PASS
> > > * vers=3,4.0,4.1,4.2,sec=sys,server=localhost (same kernel)
> > > 2. cthon04: PASS
> > > * test options "-b -g -s -l", fsc,vers=3,4.0,4.1,4.2,sec=sys
> > > * No failures, oopses or hangs
> > > 3. iozone tests: PASS
> > > * nofsc,fsc,vers=3,4.0,4.1,4.2,sec=sys,server=rhel7,rhel8
> > > * No failures, oopses, or hangs
> > > 4. xfstests/generic: PASS*
> > > * no hangs or crashes (one WARN); failures unrelated to these patches
> > > * Ran following configurations
> > > * vers=4.1,fsc,sec=sys,rhel7-server: PASS
> > > * vers=4.0,fsc,sec=sys,rhel7-server: PASS
> > > * vers=3,fsc,sec=sys,rhel7-server: PASS
> > > * vers=4.1,nofsc,sec=sys,netapp-server(pnfs/files): PASS
> > > * vers=4.1,fsc,sec=sys,netapp-server(pnfs/files): INCOMPLETE
> > > * WARN_ON fs/netfs/read_helper.c:616
> > > * ran with kernel.panic_on_oops=1
> > > * vers=4.2,fsc,sec=sys,rhel7-server: running at generic/438
> > > * vers=4.2,fsc,sec=sys,rhel8-server: running at generic/127
> > > 5. kernel build: PASS
> > > * vers=4.2,fsc,sec=sys,rhel8-server: PASS
> > >
> > > Not tested yet:
> > > * error injections (for example, connection disruptions, server errors during IO, etc)
> > > * many process mixed read/write on same file
> > > * performance
> > >
> > > Dave Wysochanski (10):
> > > NFS: Clean up nfs_readpage() and nfs_readpages()
> > > NFS: In nfs_readpage() only increment NFSIOS_READPAGES when read
> > > succeeds
> > > NFS: Refactor nfs_readpage() and nfs_readpage_async() to use
> > > nfs_readdesc
> > > NFS: Call readpage_async_filler() from nfs_readpage_async()
> > > NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async()
> > > NFS: Allow internal use of read structs and functions
> > > NFS: Convert to the netfs API and nfs_readpage to use netfs_readpage
> > > NFS: Convert readpages to readahead and use netfs_readahead for
> > > fscache
> > > NFS: Update releasepage to handle new fscache kiocb IO API
> > > NFS: update various invalidation code paths for new IO API
> > >
> > > fs/nfs/file.c | 22 +++--
> > > fs/nfs/fscache.c | 230 +++++++++++++++++++------------------------
> > > fs/nfs/fscache.h | 105 +++-----------------
> > > fs/nfs/internal.h | 8 ++
> > > fs/nfs/pagelist.c | 2 +
> > > fs/nfs/read.c | 240 ++++++++++++++++++++-------------------------
> > > fs/nfs/write.c | 10 +-
> > > include/linux/nfs_fs.h | 5 +-
> > > include/linux/nfs_iostat.h | 2 +-
> > > include/linux/nfs_page.h | 1 +
> > > include/linux/nfs_xdr.h | 1 +
> > > 11 files changed, 257 insertions(+), 369 deletions(-)
> > >
> > > --
> > > 1.8.3.1
> > >
> >
>
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