diff options
| author | Peter Lieven <pl@kamp.de> | 2016-05-19 14:48:03 +0200 |
|---|---|---|
| committer | Jeff Cody <jcody@redhat.com> | 2016-06-28 22:52:45 -0400 |
| commit | d99b26c42a1375e41404b69c3214459e929af4e3 (patch) | |
| tree | 7db5433bb2292ebd02314451e316ae1f78712906 /block/nfs.c | |
| parent | 38f8d5e0251ae7d8257cf099cb3e5a375ef60378 (diff) | |
block/nfs: add support for libnfs pagecache
upcoming libnfs will have support for a read cache that can
significantly help to speed up requests since libnfs by design
circumvents the kernel cache.
Example:
qemu -cdrom nfs://127.0.0.1/iso/my.iso?pagecache=1024
The pagecache parameters takes the maximum amount of pages to
cache. A page in libnfs is always the NFS_BLKSIZE which is
4KB.
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1463662083-20814-3-git-send-email-pl@kamp.de
Signed-off-by: Jeff Cody <jcody@redhat.com>
Diffstat (limited to 'block/nfs.c')
| -rw-r--r-- | block/nfs.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/block/nfs.c b/block/nfs.c index 60be45e8d9..15d6832c4c 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -38,6 +38,7 @@ #include <nfsc/libnfs.h> #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576 +#define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE) #define QEMU_NFS_MAX_DEBUG_LEVEL 2 typedef struct NFSClient { @@ -342,6 +343,26 @@ static int64_t nfs_client_open(NFSClient *client, const char *filename, val = QEMU_NFS_MAX_READAHEAD_SIZE; } nfs_set_readahead(client->context, val); +#ifdef LIBNFS_FEATURE_PAGECACHE + nfs_set_pagecache_ttl(client->context, 0); +#endif + client->cache_used = true; +#endif +#ifdef LIBNFS_FEATURE_PAGECACHE + nfs_set_pagecache_ttl(client->context, 0); + } else if (!strcmp(qp->p[i].name, "pagecache")) { + if (open_flags & BDRV_O_NOCACHE) { + error_setg(errp, "Cannot enable NFS pagecache " + "if cache.direct = on"); + goto fail; + } + if (val > QEMU_NFS_MAX_PAGECACHE_SIZE) { + error_report("NFS Warning: Truncating NFS pagecache" + " size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE); + val = QEMU_NFS_MAX_PAGECACHE_SIZE; + } + nfs_set_pagecache(client->context, val); + nfs_set_pagecache_ttl(client->context, 0); client->cache_used = true; #endif #ifdef LIBNFS_FEATURE_DEBUG @@ -524,7 +545,8 @@ static int nfs_reopen_prepare(BDRVReopenState *state, } if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) { - error_setg(errp, "Cannot disable cache if libnfs readahead is enabled"); + error_setg(errp, "Cannot disable cache if libnfs readahead or" + " pagecache is enabled"); return -EINVAL; } @@ -542,6 +564,15 @@ static int nfs_reopen_prepare(BDRVReopenState *state, return 0; } +#ifdef LIBNFS_FEATURE_PAGECACHE +static void nfs_invalidate_cache(BlockDriverState *bs, + Error **errp) +{ + NFSClient *client = bs->opaque; + nfs_pagecache_invalidate(client->context, client->fh); +} +#endif + static BlockDriver bdrv_nfs = { .format_name = "nfs", .protocol_name = "nfs", @@ -565,6 +596,10 @@ static BlockDriver bdrv_nfs = { .bdrv_detach_aio_context = nfs_detach_aio_context, .bdrv_attach_aio_context = nfs_attach_aio_context, + +#ifdef LIBNFS_FEATURE_PAGECACHE + .bdrv_invalidate_cache = nfs_invalidate_cache, +#endif }; static void nfs_block_init(void) |