diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/net/ceph/pagelist.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/net/ceph/pagelist.c')
-rw-r--r-- | kernel/net/ceph/pagelist.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/kernel/net/ceph/pagelist.c b/kernel/net/ceph/pagelist.c new file mode 100644 index 000000000..c7c220a73 --- /dev/null +++ b/kernel/net/ceph/pagelist.c @@ -0,0 +1,150 @@ +#include <linux/module.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/highmem.h> +#include <linux/ceph/pagelist.h> + +static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl) +{ + if (pl->mapped_tail) { + struct page *page = list_entry(pl->head.prev, struct page, lru); + kunmap(page); + pl->mapped_tail = NULL; + } +} + +void ceph_pagelist_release(struct ceph_pagelist *pl) +{ + if (!atomic_dec_and_test(&pl->refcnt)) + return; + ceph_pagelist_unmap_tail(pl); + while (!list_empty(&pl->head)) { + struct page *page = list_first_entry(&pl->head, struct page, + lru); + list_del(&page->lru); + __free_page(page); + } + ceph_pagelist_free_reserve(pl); + kfree(pl); +} +EXPORT_SYMBOL(ceph_pagelist_release); + +static int ceph_pagelist_addpage(struct ceph_pagelist *pl) +{ + struct page *page; + + if (!pl->num_pages_free) { + page = __page_cache_alloc(GFP_NOFS); + } else { + page = list_first_entry(&pl->free_list, struct page, lru); + list_del(&page->lru); + --pl->num_pages_free; + } + if (!page) + return -ENOMEM; + pl->room += PAGE_SIZE; + ceph_pagelist_unmap_tail(pl); + list_add_tail(&page->lru, &pl->head); + pl->mapped_tail = kmap(page); + return 0; +} + +int ceph_pagelist_append(struct ceph_pagelist *pl, const void *buf, size_t len) +{ + while (pl->room < len) { + size_t bit = pl->room; + int ret; + + memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), + buf, bit); + pl->length += bit; + pl->room -= bit; + buf += bit; + len -= bit; + ret = ceph_pagelist_addpage(pl); + if (ret) + return ret; + } + + memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), buf, len); + pl->length += len; + pl->room -= len; + return 0; +} +EXPORT_SYMBOL(ceph_pagelist_append); + +/* Allocate enough pages for a pagelist to append the given amount + * of data without without allocating. + * Returns: 0 on success, -ENOMEM on error. + */ +int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space) +{ + if (space <= pl->room) + return 0; + space -= pl->room; + space = (space + PAGE_SIZE - 1) >> PAGE_SHIFT; /* conv to num pages */ + + while (space > pl->num_pages_free) { + struct page *page = __page_cache_alloc(GFP_NOFS); + if (!page) + return -ENOMEM; + list_add_tail(&page->lru, &pl->free_list); + ++pl->num_pages_free; + } + return 0; +} +EXPORT_SYMBOL(ceph_pagelist_reserve); + +/* Free any pages that have been preallocated. */ +int ceph_pagelist_free_reserve(struct ceph_pagelist *pl) +{ + while (!list_empty(&pl->free_list)) { + struct page *page = list_first_entry(&pl->free_list, + struct page, lru); + list_del(&page->lru); + __free_page(page); + --pl->num_pages_free; + } + BUG_ON(pl->num_pages_free); + return 0; +} +EXPORT_SYMBOL(ceph_pagelist_free_reserve); + +/* Create a truncation point. */ +void ceph_pagelist_set_cursor(struct ceph_pagelist *pl, + struct ceph_pagelist_cursor *c) +{ + c->pl = pl; + c->page_lru = pl->head.prev; + c->room = pl->room; +} +EXPORT_SYMBOL(ceph_pagelist_set_cursor); + +/* Truncate a pagelist to the given point. Move extra pages to reserve. + * This won't sleep. + * Returns: 0 on success, + * -EINVAL if the pagelist doesn't match the trunc point pagelist + */ +int ceph_pagelist_truncate(struct ceph_pagelist *pl, + struct ceph_pagelist_cursor *c) +{ + struct page *page; + + if (pl != c->pl) + return -EINVAL; + ceph_pagelist_unmap_tail(pl); + while (pl->head.prev != c->page_lru) { + page = list_entry(pl->head.prev, struct page, lru); + /* move from pagelist to reserve */ + list_move_tail(&page->lru, &pl->free_list); + ++pl->num_pages_free; + } + pl->room = c->room; + if (!list_empty(&pl->head)) { + page = list_entry(pl->head.prev, struct page, lru); + pl->mapped_tail = kmap(page); + } + return 0; +} +EXPORT_SYMBOL(ceph_pagelist_truncate); |