| Message ID | 1310498994-12685-6-git-send-email-Trond.Myklebust@netapp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2011-07-12 22:29, Trond Myklebust wrote: > If an attempt to do pNFS fails, and we have to fall back to writing through > the MDS, then we may want to re-coalesce the requests that we already have > since the block size for the MDS read/writes may be different to that of > the DS read/writes. > > Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> > --- > fs/nfs/pagelist.c | 57 +++++++++++++++++++++++++++++++++++++++++++-- > include/linux/nfs_page.h | 3 +- > 2 files changed, 56 insertions(+), 4 deletions(-) > > diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c > index d421e19..7139dbf 100644 > --- a/fs/nfs/pagelist.c > +++ b/fs/nfs/pagelist.c > @@ -240,6 +240,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, > desc->pg_bsize = bsize; > desc->pg_base = 0; > desc->pg_moreio = 0; > + desc->pg_recoalesce = 0; > desc->pg_inode = inode; > desc->pg_ops = pg_ops; > desc->pg_ioflags = io_flags; > @@ -331,7 +332,7 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) > * Returns true if the request 'req' was successfully coalesced into the > * existing list of pages 'desc'. > */ > -int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, > +static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, > struct nfs_page *req) > { > while (!nfs_pageio_do_add_request(desc, req)) { > @@ -340,17 +341,67 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, > if (desc->pg_error < 0) > return 0; > desc->pg_moreio = 0; > + if (desc->pg_recoalesce) > + return 0; > } > return 1; > } > > +static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) > +{ > + LIST_HEAD(head); > + > + do { > + list_splice_init(&desc->pg_list, &head); > + desc->pg_bytes_written -= desc->pg_count; > + desc->pg_count = 0; > + desc->pg_base = 0; > + desc->pg_recoalesce = 0; > + > + while (!list_empty(&head)) { > + struct nfs_page *req; > + > + req = list_first_entry(&head, struct nfs_page, wb_list); > + nfs_list_remove_request(req); > + if (__nfs_pageio_add_request(desc, req)) > + continue; > + if (desc->pg_error < 0) > + return 0; > + break; > + } > + } while (desc->pg_recoalesce); > + return 1; > +} > + > +int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, > + struct nfs_page *req) > +{ > + int ret; > + > + do { > + ret = __nfs_pageio_add_request(desc, req); > + if (ret) > + break; > + if (desc->pg_error < 0) > + break; > + ret = nfs_do_recoalesce(desc); > + } while (ret); > + return ret; > +} > + > /** > * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor > * @desc: pointer to io descriptor > */ > void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) > { > - nfs_pageio_doio(desc); > + for (;;) { > + nfs_pageio_doio(desc); > + if (!desc->pg_recoalesce) > + break; > + if (!nfs_do_recoalesce(desc)) > + break; > + } nit: how about the following? do nfs_pageio_doio(desc); while (desc->pg_recoalesce && nfs_do_recoalesce(desc)); Benny > } > > /** > @@ -369,7 +420,7 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) > if (!list_empty(&desc->pg_list)) { > struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev); > if (index != prev->wb_index + 1) > - nfs_pageio_doio(desc); > + nfs_pageio_complete(desc); > } > } > > diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h > index db3194f..7241b2a 100644 > --- a/include/linux/nfs_page.h > +++ b/include/linux/nfs_page.h > @@ -68,7 +68,8 @@ struct nfs_pageio_descriptor { > size_t pg_count; > size_t pg_bsize; > unsigned int pg_base; > - char pg_moreio; > + unsigned char pg_moreio : 1, > + pg_recoalesce : 1; > > struct inode *pg_inode; > const struct nfs_pageio_ops *pg_ops; -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index d421e19..7139dbf 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -240,6 +240,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, desc->pg_bsize = bsize; desc->pg_base = 0; desc->pg_moreio = 0; + desc->pg_recoalesce = 0; desc->pg_inode = inode; desc->pg_ops = pg_ops; desc->pg_ioflags = io_flags; @@ -331,7 +332,7 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc) * Returns true if the request 'req' was successfully coalesced into the * existing list of pages 'desc'. */ -int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, +static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, struct nfs_page *req) { while (!nfs_pageio_do_add_request(desc, req)) { @@ -340,17 +341,67 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, if (desc->pg_error < 0) return 0; desc->pg_moreio = 0; + if (desc->pg_recoalesce) + return 0; } return 1; } +static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc) +{ + LIST_HEAD(head); + + do { + list_splice_init(&desc->pg_list, &head); + desc->pg_bytes_written -= desc->pg_count; + desc->pg_count = 0; + desc->pg_base = 0; + desc->pg_recoalesce = 0; + + while (!list_empty(&head)) { + struct nfs_page *req; + + req = list_first_entry(&head, struct nfs_page, wb_list); + nfs_list_remove_request(req); + if (__nfs_pageio_add_request(desc, req)) + continue; + if (desc->pg_error < 0) + return 0; + break; + } + } while (desc->pg_recoalesce); + return 1; +} + +int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, + struct nfs_page *req) +{ + int ret; + + do { + ret = __nfs_pageio_add_request(desc, req); + if (ret) + break; + if (desc->pg_error < 0) + break; + ret = nfs_do_recoalesce(desc); + } while (ret); + return ret; +} + /** * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor * @desc: pointer to io descriptor */ void nfs_pageio_complete(struct nfs_pageio_descriptor *desc) { - nfs_pageio_doio(desc); + for (;;) { + nfs_pageio_doio(desc); + if (!desc->pg_recoalesce) + break; + if (!nfs_do_recoalesce(desc)) + break; + } } /** @@ -369,7 +420,7 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index) if (!list_empty(&desc->pg_list)) { struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev); if (index != prev->wb_index + 1) - nfs_pageio_doio(desc); + nfs_pageio_complete(desc); } } diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index db3194f..7241b2a 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -68,7 +68,8 @@ struct nfs_pageio_descriptor { size_t pg_count; size_t pg_bsize; unsigned int pg_base; - char pg_moreio; + unsigned char pg_moreio : 1, + pg_recoalesce : 1; struct inode *pg_inode; const struct nfs_pageio_ops *pg_ops;
If an attempt to do pNFS fails, and we have to fall back to writing through the MDS, then we may want to re-coalesce the requests that we already have since the block size for the MDS read/writes may be different to that of the DS read/writes. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> --- fs/nfs/pagelist.c | 57 +++++++++++++++++++++++++++++++++++++++++++-- include/linux/nfs_page.h | 3 +- 2 files changed, 56 insertions(+), 4 deletions(-)