diff options
| author |   Mel Gorman <mgorman@suse.de> | 2012-07-31 16:44:51 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-31 18:42:47 -0700 |
| commit | 18022c5d8627a7a9ba8097a0f238b513fae6f5b8 (patch) | |
| tree | 57e0d0ec6a5369c56bd00957eb9c0e1220e62917 /include | |
| parent | mm: methods for teaching filesystems about PG_swapcache pages (diff) | |
| download | linux-dev-18022c5d8627a7a9ba8097a0f238b513fae6f5b8.tar.xz linux-dev-18022c5d8627a7a9ba8097a0f238b513fae6f5b8.zip | |
mm: add get_kernel_page[s] for pinning of kernel addresses for I/O
This patch adds two new APIs get_kernel_pages() and get_kernel_page() that
may be used to pin a vector of kernel addresses for IO. The initial user
is expected to be NFS for allowing pages to be written to swap using
aops->direct_IO(). Strictly speaking, swap-over-NFS only needs to pin one
page for IO but it makes sense to express the API in terms of a vector and
add a helper for pinning single pages.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blk_types.h | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 | ||||
| -rw-r--r-- | include/linux/mm.h | 4 |
3 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 0edb65dd8edd..7b7ac9ccec7a 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -160,6 +160,7 @@ enum rq_flag_bits { __REQ_FLUSH_SEQ, /* request for flush sequence */ __REQ_IO_STAT, /* account I/O stat */ __REQ_MIXED_MERGE, /* merge of different types, fail separately */ + __REQ_KERNEL, /* direct IO to kernel pages */ __REQ_NR_BITS, /* stops here */ }; @@ -201,5 +202,6 @@ enum rq_flag_bits { #define REQ_IO_STAT (1 << __REQ_IO_STAT) #define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) #define REQ_SECURE (1 << __REQ_SECURE) +#define REQ_KERNEL (1 << __REQ_KERNEL) #endif /* __LINUX_BLK_TYPES_H */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 8fabb037a48d..9d77309da153 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -165,6 +165,8 @@ struct inodes_stat_t { #define READ 0 #define WRITE RW_MASK #define READA RWA_MASK +#define KERNEL_READ (READ|REQ_KERNEL) +#define KERNEL_WRITE (WRITE|REQ_KERNEL) #define READ_SYNC (READ | REQ_SYNC) #define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE) diff --git a/include/linux/mm.h b/include/linux/mm.h index 7cdac1676b59..bd079a1b0fdc 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1019,6 +1019,10 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, struct page **pages, struct vm_area_struct **vmas); int get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages); +struct kvec; +int get_kernel_pages(const struct kvec *iov, int nr_pages, int write, + struct page **pages); +int get_kernel_page(unsigned long start, int write, struct page **pages); struct page *get_dump_page(unsigned long addr); extern int try_to_release_page(struct page * page, gfp_t gfp_mask); |