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authorMel Gorman <mgorman@suse.de>2012-07-31 16:44:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-31 18:42:47 -0700
commit18022c5d8627a7a9ba8097a0f238b513fae6f5b8 (patch)
tree57e0d0ec6a5369c56bd00957eb9c0e1220e62917 /include/linux/fs.h
parentmm: methods for teaching filesystems about PG_swapcache pages (diff)
downloadlinux-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/linux/fs.h')
-rw-r--r--include/linux/fs.h2
1 files changed, 2 insertions, 0 deletions
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)