This patch converts nfs_readpages() to nfs_readahead(). It was
applied on top of the set I just posted [1] plus Chuck's v1 patch to
convert dfprintks to tracepoints [2]. It is being tested on top of
these patches at BakeAThon against various servers, cthon, xfstests,
and my fscache unit tests. Note that Chuck may post a v3 of his
patch and this would need rebased on that patch.
Note that a nfs-utils patch will need to be done to properly account
for the changed NFSIOS_* counters.
I would consider this a "nice to have" for this cycle but I wanted
to get it out there sooner than later. As far as I know this has
been an outstanding item for the NFS client for a while and the
fscache fallback IO API clears the way for this patch.
[1] https://marc.info/?l=linux-nfs&m=163364580324243&w=2
[2] https://marc.info/?l=linux-nfs&m=163345402812426&w=2
Dave Wysochanski (1):
NFS: Convert from readpages() to readahead()
fs/nfs/file.c | 2 +-
fs/nfs/nfstrace.h | 2 +-
fs/nfs/read.c | 21 +++++++++++++++------
include/linux/nfs_fs.h | 3 +--
include/linux/nfs_iostat.h | 6 +++---
5 files changed, 21 insertions(+), 13 deletions(-)
--
1.8.3.1
Convert to the new VM readahead() API which is the preferred API
to read multiple pages, and rename the NFSIOS_* counters and the
tracepoint as needed.
Signed-off-by: Dave Wysochanski <[email protected]>
---
fs/nfs/file.c | 2 +-
fs/nfs/nfstrace.h | 2 +-
fs/nfs/read.c | 21 +++++++++++++++------
include/linux/nfs_fs.h | 3 +--
include/linux/nfs_iostat.h | 6 +++---
5 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 209dac208477..cc76d17fa97f 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -519,7 +519,7 @@ 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/nfstrace.h b/fs/nfs/nfstrace.h
index 78b0f649dd09..d2b2080765a6 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -915,7 +915,7 @@
)
);
-TRACE_EVENT(nfs_aops_readpages,
+TRACE_EVENT(nfs_aops_readahead,
TP_PROTO(
const struct inode *inode,
unsigned int nr_pages
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 927504605e0f..5c2aab47cf1d 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -395,15 +395,19 @@ 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 file *file = ractl->file;
+ struct address_space *mapping = ractl->mapping;
+ struct page *page;
+ unsigned int nr_pages = readahead_count(ractl);
+
struct nfs_readdesc desc;
struct inode *inode = mapping->host;
int ret;
- trace_nfs_aops_readpages(inode, nr_pages);
- nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
+ trace_nfs_aops_readahead(inode, nr_pages);
+ nfs_inc_stats(inode, NFSIOS_VFSREADAHEAD);
ret = -ESTALE;
if (NFS_STALE(inode))
@@ -420,13 +424,18 @@ int nfs_readpages(struct file *file, struct address_space *mapping,
nfs_pageio_init_read(&desc.pgio, inode, false,
&nfs_async_read_completion_ops);
- ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
+ ret = 0;
+ while (!ret && (page = readahead_page(ractl))) {
+ prefetchw(&page->flags);
+ ret = readpage_async_filler(&desc, page);
+ put_page(page);
+ }
nfs_pageio_complete_read(&desc.pgio);
put_nfs_open_context(desc.ctx);
out:
- return ret;
+ return;
}
int __init nfs_init_readpagecache(void)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index b9a8b925db43..6cbe3f2c5669 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -580,8 +580,7 @@ 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 *);
/*
* inline functions
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 027874c36c88..418145f23700 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -22,7 +22,7 @@
#ifndef _LINUX_NFS_IOSTAT
#define _LINUX_NFS_IOSTAT
-#define NFS_IOSTAT_VERS "1.1"
+#define NFS_IOSTAT_VERS "1.2"
/*
* NFS byte counters
@@ -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
@@ -98,7 +98,7 @@ enum nfs_stat_eventcounters {
NFSIOS_VFSACCESS,
NFSIOS_VFSUPDATEPAGE,
NFSIOS_VFSREADPAGE,
- NFSIOS_VFSREADPAGES,
+ NFSIOS_VFSREADAHEAD,
NFSIOS_VFSWRITEPAGE,
NFSIOS_VFSWRITEPAGES,
NFSIOS_VFSGETDENTS,
--
1.8.3.1
> On Oct 7, 2021, at 7:32 PM, Dave Wysochanski <[email protected]> wrote:
>
> Convert to the new VM readahead() API which is the preferred API
> to read multiple pages, and rename the NFSIOS_* counters and the
> tracepoint as needed.
>
> Signed-off-by: Dave Wysochanski <[email protected]>
> ---
> fs/nfs/file.c | 2 +-
> fs/nfs/nfstrace.h | 2 +-
> fs/nfs/read.c | 21 +++++++++++++++------
> include/linux/nfs_fs.h | 3 +--
> include/linux/nfs_iostat.h | 6 +++---
> 5 files changed, 21 insertions(+), 13 deletions(-)
>
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index 209dac208477..cc76d17fa97f 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -519,7 +519,7 @@ 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/nfstrace.h b/fs/nfs/nfstrace.h
> index 78b0f649dd09..d2b2080765a6 100644
> --- a/fs/nfs/nfstrace.h
> +++ b/fs/nfs/nfstrace.h
> @@ -915,7 +915,7 @@
> )
> );
>
> -TRACE_EVENT(nfs_aops_readpages,
> +TRACE_EVENT(nfs_aops_readahead,
In v2 and v3 of my patch, this tracepoint has already been
renamed to nfs_aop_readahead.
> TP_PROTO(
> const struct inode *inode,
> unsigned int nr_pages
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index 927504605e0f..5c2aab47cf1d 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -395,15 +395,19 @@ 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 file *file = ractl->file;
> + struct address_space *mapping = ractl->mapping;
> + struct page *page;
> + unsigned int nr_pages = readahead_count(ractl);
> +
> struct nfs_readdesc desc;
> struct inode *inode = mapping->host;
> int ret;
>
> - trace_nfs_aops_readpages(inode, nr_pages);
> - nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
> + trace_nfs_aops_readahead(inode, nr_pages);
> + nfs_inc_stats(inode, NFSIOS_VFSREADAHEAD);
>
> ret = -ESTALE;
> if (NFS_STALE(inode))
> @@ -420,13 +424,18 @@ int nfs_readpages(struct file *file, struct address_space *mapping,
> nfs_pageio_init_read(&desc.pgio, inode, false,
> &nfs_async_read_completion_ops);
>
> - ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
> + ret = 0;
> + while (!ret && (page = readahead_page(ractl))) {
> + prefetchw(&page->flags);
> + ret = readpage_async_filler(&desc, page);
> + put_page(page);
> + }
>
> nfs_pageio_complete_read(&desc.pgio);
>
> put_nfs_open_context(desc.ctx);
> out:
> - return ret;
> + return;
> }
>
> int __init nfs_init_readpagecache(void)
> diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> index b9a8b925db43..6cbe3f2c5669 100644
> --- a/include/linux/nfs_fs.h
> +++ b/include/linux/nfs_fs.h
> @@ -580,8 +580,7 @@ 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 *);
>
> /*
> * inline functions
> diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
> index 027874c36c88..418145f23700 100644
> --- a/include/linux/nfs_iostat.h
> +++ b/include/linux/nfs_iostat.h
> @@ -22,7 +22,7 @@
> #ifndef _LINUX_NFS_IOSTAT
> #define _LINUX_NFS_IOSTAT
>
> -#define NFS_IOSTAT_VERS "1.1"
> +#define NFS_IOSTAT_VERS "1.2"
>
> /*
> * NFS byte counters
> @@ -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
> @@ -98,7 +98,7 @@ enum nfs_stat_eventcounters {
> NFSIOS_VFSACCESS,
> NFSIOS_VFSUPDATEPAGE,
> NFSIOS_VFSREADPAGE,
> - NFSIOS_VFSREADPAGES,
> + NFSIOS_VFSREADAHEAD,
I'm wondering if you should add NFSIOS_VFSREADAHEAD
but leave NFSIOS_VFSREADPAGES? I don't remember exactly
how the mountstats API versioning is supposed to work.
> NFSIOS_VFSWRITEPAGE,
> NFSIOS_VFSWRITEPAGES,
> NFSIOS_VFSGETDENTS,
> --
> 1.8.3.1
>
--
Chuck Lever
On Fri, Oct 8, 2021 at 10:10 AM Chuck Lever III <[email protected]> wrote:
>
>
>
> > On Oct 7, 2021, at 7:32 PM, Dave Wysochanski <[email protected]> wrote:
> >
> > Convert to the new VM readahead() API which is the preferred API
> > to read multiple pages, and rename the NFSIOS_* counters and the
> > tracepoint as needed.
> >
> > Signed-off-by: Dave Wysochanski <[email protected]>
> > ---
> > fs/nfs/file.c | 2 +-
> > fs/nfs/nfstrace.h | 2 +-
> > fs/nfs/read.c | 21 +++++++++++++++------
> > include/linux/nfs_fs.h | 3 +--
> > include/linux/nfs_iostat.h | 6 +++---
> > 5 files changed, 21 insertions(+), 13 deletions(-)
> >
> > diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> > index 209dac208477..cc76d17fa97f 100644
> > --- a/fs/nfs/file.c
> > +++ b/fs/nfs/file.c
> > @@ -519,7 +519,7 @@ 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/nfstrace.h b/fs/nfs/nfstrace.h
> > index 78b0f649dd09..d2b2080765a6 100644
> > --- a/fs/nfs/nfstrace.h
> > +++ b/fs/nfs/nfstrace.h
> > @@ -915,7 +915,7 @@
> > )
> > );
> >
> > -TRACE_EVENT(nfs_aops_readpages,
> > +TRACE_EVENT(nfs_aops_readahead,
>
> In v2 and v3 of my patch, this tracepoint has already been
> renamed to nfs_aop_readahead.
>
Ack.
>
> > TP_PROTO(
> > const struct inode *inode,
> > unsigned int nr_pages
> > diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> > index 927504605e0f..5c2aab47cf1d 100644
> > --- a/fs/nfs/read.c
> > +++ b/fs/nfs/read.c
> > @@ -395,15 +395,19 @@ 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 file *file = ractl->file;
> > + struct address_space *mapping = ractl->mapping;
> > + struct page *page;
> > + unsigned int nr_pages = readahead_count(ractl);
> > +
> > struct nfs_readdesc desc;
> > struct inode *inode = mapping->host;
> > int ret;
> >
> > - trace_nfs_aops_readpages(inode, nr_pages);
> > - nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
> > + trace_nfs_aops_readahead(inode, nr_pages);
> > + nfs_inc_stats(inode, NFSIOS_VFSREADAHEAD);
> >
> > ret = -ESTALE;
> > if (NFS_STALE(inode))
> > @@ -420,13 +424,18 @@ int nfs_readpages(struct file *file, struct address_space *mapping,
> > nfs_pageio_init_read(&desc.pgio, inode, false,
> > &nfs_async_read_completion_ops);
> >
> > - ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
> > + ret = 0;
> > + while (!ret && (page = readahead_page(ractl))) {
> > + prefetchw(&page->flags);
> > + ret = readpage_async_filler(&desc, page);
> > + put_page(page);
> > + }
> >
> > nfs_pageio_complete_read(&desc.pgio);
> >
> > put_nfs_open_context(desc.ctx);
> > out:
> > - return ret;
> > + return;
> > }
> >
> > int __init nfs_init_readpagecache(void)
> > diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> > index b9a8b925db43..6cbe3f2c5669 100644
> > --- a/include/linux/nfs_fs.h
> > +++ b/include/linux/nfs_fs.h
> > @@ -580,8 +580,7 @@ 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 *);
> >
> > /*
> > * inline functions
> > diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
> > index 027874c36c88..418145f23700 100644
> > --- a/include/linux/nfs_iostat.h
> > +++ b/include/linux/nfs_iostat.h
> > @@ -22,7 +22,7 @@
> > #ifndef _LINUX_NFS_IOSTAT
> > #define _LINUX_NFS_IOSTAT
> >
> > -#define NFS_IOSTAT_VERS "1.1"
> > +#define NFS_IOSTAT_VERS "1.2"
> >
> > /*
> > * NFS byte counters
> > @@ -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
> > @@ -98,7 +98,7 @@ enum nfs_stat_eventcounters {
> > NFSIOS_VFSACCESS,
> > NFSIOS_VFSUPDATEPAGE,
> > NFSIOS_VFSREADPAGE,
> > - NFSIOS_VFSREADPAGES,
> > + NFSIOS_VFSREADAHEAD,
>
> I'm wondering if you should add NFSIOS_VFSREADAHEAD
> but leave NFSIOS_VFSREADPAGES? I don't remember exactly
> how the mountstats API versioning is supposed to work.
>
I don't think we need to keep this but correct me if I'm wrong.
That would mean we would have a 0 count for later kernels and I'm not
sure about that given the similarities.
You can see my nfs-utils patch for the attempt to use the versioning
in nfs-iostat.
>
> > NFSIOS_VFSWRITEPAGE,
> > NFSIOS_VFSWRITEPAGES,
> > NFSIOS_VFSGETDENTS,
> > --
> > 1.8.3.1
> >
>
> --
> Chuck Lever
>
>
>
On Sat, Oct 9, 2021 at 8:35 AM David Wysochanski <[email protected]> wrote:
>
> On Fri, Oct 8, 2021 at 10:10 AM Chuck Lever III <[email protected]> wrote:
> >
> >
> >
> > > On Oct 7, 2021, at 7:32 PM, Dave Wysochanski <[email protected]> wrote:
> > >
> > > Convert to the new VM readahead() API which is the preferred API
> > > to read multiple pages, and rename the NFSIOS_* counters and the
> > > tracepoint as needed.
> > >
> > > Signed-off-by: Dave Wysochanski <[email protected]>
> > > ---
> > > fs/nfs/file.c | 2 +-
> > > fs/nfs/nfstrace.h | 2 +-
> > > fs/nfs/read.c | 21 +++++++++++++++------
> > > include/linux/nfs_fs.h | 3 +--
> > > include/linux/nfs_iostat.h | 6 +++---
> > > 5 files changed, 21 insertions(+), 13 deletions(-)
> > >
> > > diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> > > index 209dac208477..cc76d17fa97f 100644
> > > --- a/fs/nfs/file.c
> > > +++ b/fs/nfs/file.c
> > > @@ -519,7 +519,7 @@ 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/nfstrace.h b/fs/nfs/nfstrace.h
> > > index 78b0f649dd09..d2b2080765a6 100644
> > > --- a/fs/nfs/nfstrace.h
> > > +++ b/fs/nfs/nfstrace.h
> > > @@ -915,7 +915,7 @@
> > > )
> > > );
> > >
> > > -TRACE_EVENT(nfs_aops_readpages,
> > > +TRACE_EVENT(nfs_aops_readahead,
> >
> > In v2 and v3 of my patch, this tracepoint has already been
> > renamed to nfs_aop_readahead.
> >
>
> Ack.
>
> >
> > > TP_PROTO(
> > > const struct inode *inode,
> > > unsigned int nr_pages
> > > diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> > > index 927504605e0f..5c2aab47cf1d 100644
> > > --- a/fs/nfs/read.c
> > > +++ b/fs/nfs/read.c
> > > @@ -395,15 +395,19 @@ 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 file *file = ractl->file;
> > > + struct address_space *mapping = ractl->mapping;
> > > + struct page *page;
> > > + unsigned int nr_pages = readahead_count(ractl);
> > > +
> > > struct nfs_readdesc desc;
> > > struct inode *inode = mapping->host;
> > > int ret;
> > >
> > > - trace_nfs_aops_readpages(inode, nr_pages);
> > > - nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
> > > + trace_nfs_aops_readahead(inode, nr_pages);
> > > + nfs_inc_stats(inode, NFSIOS_VFSREADAHEAD);
> > >
> > > ret = -ESTALE;
> > > if (NFS_STALE(inode))
> > > @@ -420,13 +424,18 @@ int nfs_readpages(struct file *file, struct address_space *mapping,
> > > nfs_pageio_init_read(&desc.pgio, inode, false,
> > > &nfs_async_read_completion_ops);
> > >
> > > - ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
> > > + ret = 0;
> > > + while (!ret && (page = readahead_page(ractl))) {
> > > + prefetchw(&page->flags);
> > > + ret = readpage_async_filler(&desc, page);
> > > + put_page(page);
> > > + }
> > >
> > > nfs_pageio_complete_read(&desc.pgio);
> > >
> > > put_nfs_open_context(desc.ctx);
> > > out:
> > > - return ret;
> > > + return;
> > > }
> > >
> > > int __init nfs_init_readpagecache(void)
> > > diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
> > > index b9a8b925db43..6cbe3f2c5669 100644
> > > --- a/include/linux/nfs_fs.h
> > > +++ b/include/linux/nfs_fs.h
> > > @@ -580,8 +580,7 @@ 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 *);
> > >
> > > /*
> > > * inline functions
> > > diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
> > > index 027874c36c88..418145f23700 100644
> > > --- a/include/linux/nfs_iostat.h
> > > +++ b/include/linux/nfs_iostat.h
> > > @@ -22,7 +22,7 @@
> > > #ifndef _LINUX_NFS_IOSTAT
> > > #define _LINUX_NFS_IOSTAT
> > >
> > > -#define NFS_IOSTAT_VERS "1.1"
> > > +#define NFS_IOSTAT_VERS "1.2"
> > >
> > > /*
> > > * NFS byte counters
> > > @@ -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
> > > @@ -98,7 +98,7 @@ enum nfs_stat_eventcounters {
> > > NFSIOS_VFSACCESS,
> > > NFSIOS_VFSUPDATEPAGE,
> > > NFSIOS_VFSREADPAGE,
> > > - NFSIOS_VFSREADPAGES,
> > > + NFSIOS_VFSREADAHEAD,
> >
> > I'm wondering if you should add NFSIOS_VFSREADAHEAD
> > but leave NFSIOS_VFSREADPAGES? I don't remember exactly
> > how the mountstats API versioning is supposed to work.
> >
>
> I don't think we need to keep this but correct me if I'm wrong.
> That would mean we would have a 0 count for later kernels and I'm not
> sure about that given the similarities.
It may matter in the case of "old nfs-utils" and newer kernel.
Do we want nfs-utils to display 0 for VFSREADPAGES count in that case?
Or would users be more confused by the fact this value is always 0 and
there's no notion of "VFSREADAHEAD" counts in older nfs-utils?
Would users be more surprised by 0 here or the fact there's a more
subtle change in the interface?
I would say the permanent 0 value would be most surprising to users so
I'd shy away from it.
> You can see my nfs-utils patch for the attempt to use the versioning
> in nfs-iostat.
>
> >
> > > NFSIOS_VFSWRITEPAGE,
> > > NFSIOS_VFSWRITEPAGES,
> > > NFSIOS_VFSGETDENTS,
> > > --
> > > 1.8.3.1
> > >
> >
> > --
> > Chuck Lever
> >
> >
> >
On Fri, 2021-10-08 at 14:09 +0000, Chuck Lever III wrote:
>
>
> > On Oct 7, 2021, at 7:32 PM, Dave Wysochanski <[email protected]>
> > wrote:
> >
> > Convert to the new VM readahead() API which is the preferred API
> > to read multiple pages, and rename the NFSIOS_* counters and the
> > tracepoint as needed.
> >
> > Signed-off-by: Dave Wysochanski <[email protected]>
> > ---
> > fs/nfs/file.c | 2 +-
> > fs/nfs/nfstrace.h | 2 +-
> > fs/nfs/read.c | 21 +++++++++++++++------
> > include/linux/nfs_fs.h | 3 +--
> > include/linux/nfs_iostat.h | 6 +++---
> > 5 files changed, 21 insertions(+), 13 deletions(-)
> >
> > diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> > index 209dac208477..cc76d17fa97f 100644
> > --- a/fs/nfs/file.c
> > +++ b/fs/nfs/file.c
> > @@ -519,7 +519,7 @@ 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/nfstrace.h b/fs/nfs/nfstrace.h
> > index 78b0f649dd09..d2b2080765a6 100644
> > --- a/fs/nfs/nfstrace.h
> > +++ b/fs/nfs/nfstrace.h
> > @@ -915,7 +915,7 @@
> > )
> > );
> >
> > -TRACE_EVENT(nfs_aops_readpages,
> > +TRACE_EVENT(nfs_aops_readahead,
>
> In v2 and v3 of my patch, this tracepoint has already been
> renamed to nfs_aop_readahead.
Does that mean you're going to resend, Chuck? All I have is your v1..
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
[email protected]
> On Oct 15, 2021, at 3:42 AM, Trond Myklebust <[email protected]> wrote:
>
> On Fri, 2021-10-08 at 14:09 +0000, Chuck Lever III wrote:
>>
>>
>>> On Oct 7, 2021, at 7:32 PM, Dave Wysochanski <[email protected]>
>>> wrote:
>>>
>>> Convert to the new VM readahead() API which is the preferred API
>>> to read multiple pages, and rename the NFSIOS_* counters and the
>>> tracepoint as needed.
>>>
>>> Signed-off-by: Dave Wysochanski <[email protected]>
>>> ---
>>> fs/nfs/file.c | 2 +-
>>> fs/nfs/nfstrace.h | 2 +-
>>> fs/nfs/read.c | 21 +++++++++++++++------
>>> include/linux/nfs_fs.h | 3 +--
>>> include/linux/nfs_iostat.h | 6 +++---
>>> 5 files changed, 21 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
>>> index 209dac208477..cc76d17fa97f 100644
>>> --- a/fs/nfs/file.c
>>> +++ b/fs/nfs/file.c
>>> @@ -519,7 +519,7 @@ 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/nfstrace.h b/fs/nfs/nfstrace.h
>>> index 78b0f649dd09..d2b2080765a6 100644
>>> --- a/fs/nfs/nfstrace.h
>>> +++ b/fs/nfs/nfstrace.h
>>> @@ -915,7 +915,7 @@
>>> )
>>> );
>>>
>>> -TRACE_EVENT(nfs_aops_readpages,
>>> +TRACE_EVENT(nfs_aops_readahead,
>>
>> In v2 and v3 of my patch, this tracepoint has already been
>> renamed to nfs_aop_readahead.
>
> Does that mean you're going to resend, Chuck?
I re-sent this one patch a few days ago, but I can re-send the whole series again to be sure everyone has the latest.