diff mbox series

[01/13] fuse: support folios in struct fuse_args_pages and fuse_copy_pages()

Message ID 20241002165253.3872513-2-joannelkoong@gmail.com (mailing list archive)
State New
Headers show
Series fuse: use folios instead of pages for requests | expand

Commit Message

Joanne Koong Oct. 2, 2024, 4:52 p.m. UTC
This adds support in struct fuse_args_pages and fuse_copy_pages() for
using folios instead of pages for transferring data. Both folios and
pages must be supported right now in struct fuse_args_pages and
fuse_copy_pages() until all request types have been converted to use
folios. Once all have been converted, then
struct fuse_args_pages and fuse_copy_pages() will only support folios.

Right now in fuse, all folios are one page (large folios are not yet
supported). As such, copying folio->page is sufficient for copying
the entire folio in fuse_copy_pages().

No functional changes.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
 fs/fuse/dev.c    | 36 ++++++++++++++++++++++++++++--------
 fs/fuse/fuse_i.h | 22 +++++++++++++++++++---
 2 files changed, 47 insertions(+), 11 deletions(-)

Comments

Josef Bacik Oct. 18, 2024, 7:48 p.m. UTC | #1
On Wed, Oct 02, 2024 at 09:52:41AM -0700, Joanne Koong wrote:
> This adds support in struct fuse_args_pages and fuse_copy_pages() for
> using folios instead of pages for transferring data. Both folios and
> pages must be supported right now in struct fuse_args_pages and
> fuse_copy_pages() until all request types have been converted to use
> folios. Once all have been converted, then
> struct fuse_args_pages and fuse_copy_pages() will only support folios.
> 
> Right now in fuse, all folios are one page (large folios are not yet
> supported). As such, copying folio->page is sufficient for copying
> the entire folio in fuse_copy_pages().
> 
> No functional changes.
> 
> Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
> ---
>  fs/fuse/dev.c    | 36 ++++++++++++++++++++++++++++--------
>  fs/fuse/fuse_i.h | 22 +++++++++++++++++++---
>  2 files changed, 47 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index 7e4c5be45aec..cd9c5e0eefca 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1028,17 +1028,37 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
>  	struct fuse_req *req = cs->req;
>  	struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args);
>  
> +	if (ap->uses_folios) {
> +		for (i = 0; i < ap->num_folios && (nbytes || zeroing); i++) {
> +			int err;
> +			unsigned int offset = ap->folio_descs[i].offset;
> +			unsigned int count = min(nbytes, ap->folio_descs[i].length);
> +			struct page *orig, *pagep;
>  
> -	for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) {
> -		int err;
> -		unsigned int offset = ap->descs[i].offset;
> -		unsigned int count = min(nbytes, ap->descs[i].length);
> +			orig = pagep = &ap->folios[i]->page;
>  
> -		err = fuse_copy_page(cs, &ap->pages[i], offset, count, zeroing);
> -		if (err)
> -			return err;
> +			err = fuse_copy_page(cs, &pagep, offset, count, zeroing);
> +			if (err)
> +				return err;
> +
> +			nbytes -= count;
> +
> +			/* Check if the folio was replaced in the page cache */

This comment confused me, I think it would be better to say something like

/*
 * fuse_copy_page may have moved a page from a pipe instead of copying into our
 * given page, so update the folios if it was replaced.
 */

Or something like that.  Thanks,

Josef
diff mbox series

Patch

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 7e4c5be45aec..cd9c5e0eefca 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1028,17 +1028,37 @@  static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
 	struct fuse_req *req = cs->req;
 	struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args);
 
+	if (ap->uses_folios) {
+		for (i = 0; i < ap->num_folios && (nbytes || zeroing); i++) {
+			int err;
+			unsigned int offset = ap->folio_descs[i].offset;
+			unsigned int count = min(nbytes, ap->folio_descs[i].length);
+			struct page *orig, *pagep;
 
-	for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) {
-		int err;
-		unsigned int offset = ap->descs[i].offset;
-		unsigned int count = min(nbytes, ap->descs[i].length);
+			orig = pagep = &ap->folios[i]->page;
 
-		err = fuse_copy_page(cs, &ap->pages[i], offset, count, zeroing);
-		if (err)
-			return err;
+			err = fuse_copy_page(cs, &pagep, offset, count, zeroing);
+			if (err)
+				return err;
+
+			nbytes -= count;
+
+			/* Check if the folio was replaced in the page cache */
+			if (pagep != orig)
+				ap->folios[i] = page_folio(pagep);
+		}
+	} else {
+		for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) {
+			int err;
+			unsigned int offset = ap->descs[i].offset;
+			unsigned int count = min(nbytes, ap->descs[i].length);
+
+			err = fuse_copy_page(cs, &ap->pages[i], offset, count, zeroing);
+			if (err)
+				return err;
 
-		nbytes -= count;
+			nbytes -= count;
+		}
 	}
 	return 0;
 }
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 7ff00bae4a84..dcc0ab4bea78 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -291,6 +291,12 @@  struct fuse_page_desc {
 	unsigned int offset;
 };
 
+/** FUSE folio descriptor */
+struct fuse_folio_desc {
+	unsigned int length;
+	unsigned int offset;
+};
+
 struct fuse_args {
 	uint64_t nodeid;
 	uint32_t opcode;
@@ -316,9 +322,19 @@  struct fuse_args {
 
 struct fuse_args_pages {
 	struct fuse_args args;
-	struct page **pages;
-	struct fuse_page_desc *descs;
-	unsigned int num_pages;
+	union {
+		struct {
+			struct page **pages;
+			struct fuse_page_desc *descs;
+			unsigned int num_pages;
+		};
+		struct {
+			struct folio **folios;
+			struct fuse_folio_desc *folio_descs;
+			unsigned int num_folios;
+		};
+	};
+	bool uses_folios;
 };
 
 struct fuse_release_args {