From: Mel Gorman <mgorman@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>,
Linux-Netdev <netdev@vger.kernel.org>,
Linux-NFS <linux-nfs@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>,
Trond Myklebust <Trond.Myklebust@netapp.com>,
Neil Brown <neilb@suse.de>, Christoph Hellwig <hch@infradead.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Mike Christie <michaelc@cs.wisc.edu>,
Eric B Munson <emunson@mgebm.net>, Mel Gorman <mgorman@suse.de>
Subject: [PATCH 05/12] mm: swap: Implement generic handler for swap_activate
Date: Thu, 10 May 2012 14:54:18 +0100 [thread overview]
Message-ID: <1336658065-24851-6-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1336658065-24851-1-git-send-email-mgorman@suse.de>
The version of swap_activate introduced is sufficient for swap-over-NFS
but would not provide enough information to implement a generic handler.
This patch shuffles things slightly to ensure the same information is
available for aops->swap_activate() as is available to the core.
No functionality change.
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
include/linux/fs.h | 6 ++--
include/linux/swap.h | 5 +++
mm/page_io.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
mm/swapfile.c | 91 +++----------------------------------------------
4 files changed, 106 insertions(+), 88 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0dcd1e8..d48e8b8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -417,6 +417,7 @@ struct kstatfs;
struct vm_area_struct;
struct vfsmount;
struct cred;
+struct swap_info_struct;
extern void __init inode_init(void);
extern void __init inode_init_early(void);
@@ -628,8 +629,9 @@ struct address_space_operations {
int (*error_remove_page)(struct address_space *, struct page *);
/* swapfile support */
- int (*swap_activate)(struct file *file);
- int (*swap_deactivate)(struct file *file);
+ int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
+ sector_t *span);
+ void (*swap_deactivate)(struct file *file);
};
extern const struct address_space_operations empty_aops;
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 6b40350..4ab2276 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -320,6 +320,11 @@ extern int swap_writepage(struct page *page, struct writeback_control *wbc);
extern int swap_set_page_dirty(struct page *page);
extern void end_swap_bio_read(struct bio *bio, int err);
+int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
+ unsigned long nr_pages, sector_t start_block);
+int generic_swapfile_activate(struct swap_info_struct *, struct file *,
+ sector_t *);
+
/* linux/mm/swap_state.c */
extern struct address_space swapper_space;
#define total_swapcache_pages swapper_space.nrpages
diff --git a/mm/page_io.c b/mm/page_io.c
index 68d8357..f363261 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -86,6 +86,98 @@ void end_swap_bio_read(struct bio *bio, int err)
bio_put(bio);
}
+int generic_swapfile_activate(struct swap_info_struct *sis,
+ struct file *swap_file,
+ sector_t *span)
+{
+ struct address_space *mapping = swap_file->f_mapping;
+ struct inode *inode = mapping->host;
+ unsigned blocks_per_page;
+ unsigned long page_no;
+ unsigned blkbits;
+ sector_t probe_block;
+ sector_t last_block;
+ sector_t lowest_block = -1;
+ sector_t highest_block = 0;
+ int nr_extents = 0;
+ int ret;
+
+ blkbits = inode->i_blkbits;
+ blocks_per_page = PAGE_SIZE >> blkbits;
+
+ /*
+ * Map all the blocks into the extent list. This code doesn't try
+ * to be very smart.
+ */
+ probe_block = 0;
+ page_no = 0;
+ last_block = i_size_read(inode) >> blkbits;
+ while ((probe_block + blocks_per_page) <= last_block &&
+ page_no < sis->max) {
+ unsigned block_in_page;
+ sector_t first_block;
+
+ first_block = bmap(inode, probe_block);
+ if (first_block == 0)
+ goto bad_bmap;
+
+ /*
+ * It must be PAGE_SIZE aligned on-disk
+ */
+ if (first_block & (blocks_per_page - 1)) {
+ probe_block++;
+ goto reprobe;
+ }
+
+ for (block_in_page = 1; block_in_page < blocks_per_page;
+ block_in_page++) {
+ sector_t block;
+
+ block = bmap(inode, probe_block + block_in_page);
+ if (block == 0)
+ goto bad_bmap;
+ if (block != first_block + block_in_page) {
+ /* Discontiguity */
+ probe_block++;
+ goto reprobe;
+ }
+ }
+
+ first_block >>= (PAGE_SHIFT - blkbits);
+ if (page_no) { /* exclude the header page */
+ if (first_block < lowest_block)
+ lowest_block = first_block;
+ if (first_block > highest_block)
+ highest_block = first_block;
+ }
+
+ /*
+ * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
+ */
+ ret = add_swap_extent(sis, page_no, 1, first_block);
+ if (ret < 0)
+ goto out;
+ nr_extents += ret;
+ page_no++;
+ probe_block += blocks_per_page;
+reprobe:
+ continue;
+ }
+ ret = nr_extents;
+ *span = 1 + highest_block - lowest_block;
+ if (page_no == 0)
+ page_no = 1; /* force Empty message */
+ sis->max = page_no;
+ sis->pages = page_no - 1;
+ sis->highest_bit = page_no - 1;
+out:
+ return ret;
+bad_bmap:
+ printk(KERN_ERR "swapon: swapfile has holes\n");
+ ret = -EINVAL;
+ goto out;
+}
+
/*
* We may have stale swap cache pages in memory: notice
* them here and get rid of the unnecessary final write.
diff --git a/mm/swapfile.c b/mm/swapfile.c
index fe2ed44..80b3415 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1358,7 +1358,7 @@ static void destroy_swap_extents(struct swap_info_struct *sis)
*
* This function rather assumes that it is called in ascending page order.
*/
-static int
+int
add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
unsigned long nr_pages, sector_t start_block)
{
@@ -1434,106 +1434,25 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
struct file *swap_file = sis->swap_file;
struct address_space *mapping = swap_file->f_mapping;
struct inode *inode = mapping->host;
- unsigned blocks_per_page;
- unsigned long page_no;
- unsigned blkbits;
- sector_t probe_block;
- sector_t last_block;
- sector_t lowest_block = -1;
- sector_t highest_block = 0;
- int nr_extents = 0;
int ret;
if (S_ISBLK(inode->i_mode)) {
ret = add_swap_extent(sis, 0, sis->max, 0);
*span = sis->pages;
- goto out;
+ return ret;
}
if (mapping->a_ops->swap_activate) {
- ret = mapping->a_ops->swap_activate(swap_file);
+ ret = mapping->a_ops->swap_activate(sis, swap_file, span);
if (!ret) {
sis->flags |= SWP_FILE;
ret = add_swap_extent(sis, 0, sis->max, 0);
*span = sis->pages;
}
- goto out;
+ return ret;
}
- blkbits = inode->i_blkbits;
- blocks_per_page = PAGE_SIZE >> blkbits;
-
- /*
- * Map all the blocks into the extent list. This code doesn't try
- * to be very smart.
- */
- probe_block = 0;
- page_no = 0;
- last_block = i_size_read(inode) >> blkbits;
- while ((probe_block + blocks_per_page) <= last_block &&
- page_no < sis->max) {
- unsigned block_in_page;
- sector_t first_block;
-
- first_block = bmap(inode, probe_block);
- if (first_block == 0)
- goto bad_bmap;
-
- /*
- * It must be PAGE_SIZE aligned on-disk
- */
- if (first_block & (blocks_per_page - 1)) {
- probe_block++;
- goto reprobe;
- }
-
- for (block_in_page = 1; block_in_page < blocks_per_page;
- block_in_page++) {
- sector_t block;
-
- block = bmap(inode, probe_block + block_in_page);
- if (block == 0)
- goto bad_bmap;
- if (block != first_block + block_in_page) {
- /* Discontiguity */
- probe_block++;
- goto reprobe;
- }
- }
-
- first_block >>= (PAGE_SHIFT - blkbits);
- if (page_no) { /* exclude the header page */
- if (first_block < lowest_block)
- lowest_block = first_block;
- if (first_block > highest_block)
- highest_block = first_block;
- }
-
- /*
- * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
- */
- ret = add_swap_extent(sis, page_no, 1, first_block);
- if (ret < 0)
- goto out;
- nr_extents += ret;
- page_no++;
- probe_block += blocks_per_page;
-reprobe:
- continue;
- }
- ret = nr_extents;
- *span = 1 + highest_block - lowest_block;
- if (page_no == 0)
- page_no = 1; /* force Empty message */
- sis->max = page_no;
- sis->pages = page_no - 1;
- sis->highest_bit = page_no - 1;
-out:
- return ret;
-bad_bmap:
- printk(KERN_ERR "swapon: swapfile has holes\n");
- ret = -EINVAL;
- goto out;
+ return generic_swapfile_activate(sis, swap_file, span);
}
static void enable_swap_info(struct swap_info_struct *p, int prio,
--
1.7.9.2
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next prev parent reply other threads:[~2012-05-10 13:54 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-10 13:54 [PATCH 00/12] Swap-over-NFS without deadlocking V4 Mel Gorman
2012-05-10 13:54 ` [PATCH 01/12] netvm: Prevent a stream-specific deadlock Mel Gorman
2012-05-11 5:10 ` David Miller
2012-05-14 10:56 ` Mel Gorman
2012-05-14 20:26 ` David Miller
[not found] ` <20120514.162634.1094732813264319951.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2012-05-15 9:14 ` Mel Gorman
2012-05-15 9:47 ` Peter Zijlstra
2012-05-15 10:08 ` Mel Gorman
2012-05-10 13:54 ` [PATCH 02/12] selinux: tag avc cache alloc as non-critical Mel Gorman
2012-05-10 14:14 ` Casey Schaufler
2012-05-10 14:25 ` Eric Paris
2012-05-10 13:54 ` [PATCH 03/12] mm: Methods for teaching filesystems about PG_swapcache pages Mel Gorman
2012-05-10 13:54 ` [PATCH 04/12] mm: Add support for a filesystem to activate swap files and use direct_IO for writing swap pages Mel Gorman
2012-05-10 13:54 ` Mel Gorman [this message]
2012-05-10 13:54 ` [PATCH 06/12] mm: Add get_kernel_page[s] for pinning of kernel addresses for I/O Mel Gorman
2012-05-10 13:54 ` [PATCH 07/12] mm: Add support for direct_IO to highmem pages Mel Gorman
2012-05-10 13:54 ` [PATCH 08/12] nfs: teach the NFS client how to treat PG_swapcache pages Mel Gorman
2012-05-10 13:54 ` [PATCH 09/12] nfs: disable data cache revalidation for swapfiles Mel Gorman
2012-05-10 13:54 ` [PATCH 10/12] nfs: enable swap on NFS Mel Gorman
2012-05-10 13:54 ` [PATCH 11/12] nfs: Prevent page allocator recursions with swap over NFS Mel Gorman
2012-05-10 13:54 ` [PATCH 12/12] Avoid dereferencing bd_disk during swap_entry_free for network storage Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2012-05-17 14:51 [PATCH 00/12] Swap-over-NFS without deadlocking V5 Mel Gorman
2012-05-17 14:51 ` [PATCH 05/12] mm: swap: Implement generic handler for swap_activate Mel Gorman
2012-06-20 9:37 [PATCH 00/12] Swap-over-NFS without deadlocking V6 Mel Gorman
2012-06-20 9:37 ` [PATCH 05/12] mm: swap: Implement generic handler for swap_activate Mel Gorman
2012-06-20 16:09 ` Rik van Riel
2012-06-22 14:30 [PATCH 00/12] Swap-over-NFS without deadlocking V7 Mel Gorman
2012-06-22 14:31 ` [PATCH 05/12] mm: swap: Implement generic handler for swap_activate Mel Gorman
2012-06-29 13:33 [PATCH 00/12] Swap-over-NFS without deadlocking V8 Mel Gorman
2012-06-29 13:33 ` [PATCH 05/12] mm: swap: Implement generic handler for swap_activate Mel Gorman
2012-07-12 6:40 [PATCH 00/12] Swap-over-NFS without deadlocking V9 Mel Gorman
2012-07-12 6:40 ` [PATCH 05/12] mm: swap: Implement generic handler for swap_activate Mel Gorman
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