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authorWeston Andros Adamson <dros@primarydata.com>2014-09-19 18:55:07 +0400
committerTom Haynes <loghyr@primarydata.com>2015-02-03 22:06:45 +0300
commita7d42ddb3099727f58366fa006f850a219cce6c8 (patch)
treec794857eb5c3ca29f77e259ecd3c155f841134d1 /include/linux/nfs_page.h
parentb57ff1303a2d4d1484c7a82bd80a3e014d6cdf5e (diff)
downloadlinux-a7d42ddb3099727f58366fa006f850a219cce6c8.tar.xz
nfs: add mirroring support to pgio layer
This patch adds mirrored write support to the pgio layer. The default is to use one mirror, but pgio callers may define callbacks to change this to any value up to the (arbitrarily selected) limit of 16. The basic idea is to break out members of nfs_pageio_descriptor that cannot be shared between mirrored DSes and put them in a new structure. Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Diffstat (limited to 'include/linux/nfs_page.h')
-rw-r--r--include/linux/nfs_page.h20
1 files changed, 17 insertions, 3 deletions
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 479c566c4ddc..3eb072dbce83 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -58,6 +58,8 @@ struct nfs_pageio_ops {
size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *,
struct nfs_page *);
int (*pg_doio)(struct nfs_pageio_descriptor *);
+ unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *,
+ struct nfs_page *);
void (*pg_cleanup)(struct nfs_pageio_descriptor *);
};
@@ -74,15 +76,17 @@ struct nfs_rw_ops {
struct rpc_task_setup *, int);
};
-struct nfs_pageio_descriptor {
+struct nfs_pgio_mirror {
struct list_head pg_list;
unsigned long pg_bytes_written;
size_t pg_count;
size_t pg_bsize;
unsigned int pg_base;
- unsigned char pg_moreio : 1,
- pg_recoalesce : 1;
+ unsigned char pg_recoalesce : 1;
+};
+struct nfs_pageio_descriptor {
+ unsigned char pg_moreio : 1;
struct inode *pg_inode;
const struct nfs_pageio_ops *pg_ops;
const struct nfs_rw_ops *pg_rw_ops;
@@ -93,8 +97,18 @@ struct nfs_pageio_descriptor {
struct pnfs_layout_segment *pg_lseg;
struct nfs_direct_req *pg_dreq;
void *pg_layout_private;
+ unsigned int pg_bsize; /* default bsize for mirrors */
+
+ u32 pg_mirror_count;
+ struct nfs_pgio_mirror *pg_mirrors;
+ struct nfs_pgio_mirror pg_mirrors_static[1];
+ struct nfs_pgio_mirror *pg_mirrors_dynamic;
+ u32 pg_mirror_idx; /* current mirror */
};
+/* arbitrarily selected limit to number of mirrors */
+#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
+
#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,