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author | Christoph Lameter <clameter@sgi.com> | 2006-02-01 11:05:41 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-01 16:53:17 (GMT) |
commit | e965f9630c651fa4249039fd4b80c9392d07a856 (patch) | |
tree | 1353dd536d0ee549c30e462086624c21788ee9d2 | |
parent | 7e2ab150d1b3b286a4c864c60a549b2601777b63 (diff) | |
download | linux-fsl-qoriq-e965f9630c651fa4249039fd4b80c9392d07a856.tar.xz |
[PATCH] Direct Migration V9: Avoid writeback / page_migrate() method
Migrate a page with buffers without requiring writeback
This introduces a new address space operation migratepage() that may be used
by a filesystem to implement its own version of page migration.
A version is provided that migrates buffers attached to pages. Some
filesystems (ext2, ext3, xfs) are modified to utilize this feature.
The swapper address space operation are modified so that a regular
migrate_page() will occur for anonymous pages without writeback (migrate_pages
forces every anonymous page to have a swap entry).
Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | fs/buffer.c | 60 | ||||
-rw-r--r-- | fs/ext2/inode.c | 2 | ||||
-rw-r--r-- | fs/ext3/inode.c | 2 | ||||
-rw-r--r-- | fs/xfs/linux-2.6/xfs_aops.c | 1 | ||||
-rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 1 | ||||
-rw-r--r-- | include/linux/fs.h | 8 | ||||
-rw-r--r-- | include/linux/swap.h | 5 | ||||
-rw-r--r-- | mm/rmap.c | 1 | ||||
-rw-r--r-- | mm/swap_state.c | 1 | ||||
-rw-r--r-- | mm/vmscan.c | 20 |
10 files changed, 100 insertions, 1 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 3dc712f..8bcbac8 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3050,6 +3050,66 @@ asmlinkage long sys_bdflush(int func, long data) } /* + * Migration function for pages with buffers. This function can only be used + * if the underlying filesystem guarantees that no other references to "page" + * exist. + */ +#ifdef CONFIG_MIGRATION +int buffer_migrate_page(struct page *newpage, struct page *page) +{ + struct address_space *mapping = page->mapping; + struct buffer_head *bh, *head; + + if (!mapping) + return -EAGAIN; + + if (!page_has_buffers(page)) + return migrate_page(newpage, page); + + head = page_buffers(page); + + if (migrate_page_remove_references(newpage, page, 3)) + return -EAGAIN; + + bh = head; + do { + get_bh(bh); + lock_buffer(bh); + bh = bh->b_this_page; + + } while (bh != head); + + ClearPagePrivate(page); + set_page_private(newpage, page_private(page)); + set_page_private(page, 0); + put_page(page); + get_page(newpage); + + bh = head; + do { + set_bh_page(bh, newpage, bh_offset(bh)); + bh = bh->b_this_page; + + } while (bh != head); + + SetPagePrivate(newpage); + + migrate_page_copy(newpage, page); + + bh = head; + do { + unlock_buffer(bh); + put_bh(bh); + bh = bh->b_this_page; + + } while (bh != head); + + return 0; +} +EXPORT_SYMBOL(buffer_migrate_page); +#endif + +/* * Buffer-head allocation */ static kmem_cache_t *bh_cachep; diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index e7d3f05..a717837 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -706,6 +706,7 @@ struct address_space_operations ext2_aops = { .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, + .migratepage = buffer_migrate_page, }; struct address_space_operations ext2_aops_xip = { @@ -723,6 +724,7 @@ struct address_space_operations ext2_nobh_aops = { .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, + .migratepage = buffer_migrate_page, }; /* diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 8824e84..3fc4238 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1559,6 +1559,7 @@ static struct address_space_operations ext3_ordered_aops = { .invalidatepage = ext3_invalidatepage, .releasepage = ext3_releasepage, .direct_IO = ext3_direct_IO, + .migratepage = buffer_migrate_page, }; static struct address_space_operations ext3_writeback_aops = { @@ -1572,6 +1573,7 @@ static struct address_space_operations ext3_writeback_aops = { .invalidatepage = ext3_invalidatepage, .releasepage = ext3_releasepage, .direct_IO = ext3_direct_IO, + .migratepage = buffer_migrate_page, }; static struct address_space_operations ext3_journalled_aops = { diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 1206267..9892268 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -1462,4 +1462,5 @@ struct address_space_operations linvfs_aops = { .commit_write = generic_commit_write, .bmap = linvfs_bmap, .direct_IO = linvfs_direct_IO, + .migratepage = buffer_migrate_page, }; diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index a36a8e3..bfb4f29 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -1521,6 +1521,7 @@ xfs_mapping_buftarg( struct address_space *mapping; static struct address_space_operations mapping_aops = { .sync_page = block_sync_page, + .migratepage = fail_migrate_page, }; inode = new_inode(bdev->bd_inode->i_sb); diff --git a/include/linux/fs.h b/include/linux/fs.h index 84bb449..e059da9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -363,6 +363,8 @@ struct address_space_operations { loff_t offset, unsigned long nr_segs); struct page* (*get_xip_page)(struct address_space *, sector_t, int); + /* migrate the contents of a page to the specified target */ + int (*migratepage) (struct page *, struct page *); }; struct backing_dev_info; @@ -1719,6 +1721,12 @@ extern void simple_release_fs(struct vfsmount **mount, int *count); extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t *, const void *, size_t); +#ifdef CONFIG_MIGRATION +extern int buffer_migrate_page(struct page *, struct page *); +#else +#define buffer_migrate_page NULL +#endif + extern int inode_change_ok(struct inode *, struct iattr *); extern int __must_check inode_setattr(struct inode *, struct iattr *); diff --git a/include/linux/swap.h b/include/linux/swap.h index 229b6d0..f3e17d5 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -193,13 +193,18 @@ extern int isolate_lru_page(struct page *p); extern int putback_lru_pages(struct list_head *l); extern int migrate_page(struct page *, struct page *); extern void migrate_page_copy(struct page *, struct page *); +extern int migrate_page_remove_references(struct page *, struct page *, int); extern int migrate_pages(struct list_head *l, struct list_head *t, struct list_head *moved, struct list_head *failed); +extern int fail_migrate_page(struct page *, struct page *); #else static inline int isolate_lru_page(struct page *p) { return -ENOSYS; } static inline int putback_lru_pages(struct list_head *l) { return 0; } static inline int migrate_pages(struct list_head *l, struct list_head *t, struct list_head *moved, struct list_head *failed) { return -ENOSYS; } +/* Possible settings for the migrate_page() method in address_operations */ +#define migrate_page NULL +#define fail_migrate_page NULL #endif #ifdef CONFIG_MMU @@ -233,6 +233,7 @@ void remove_from_swap(struct page *page) delete_from_swap_cache(page); } +EXPORT_SYMBOL(remove_from_swap); #endif /* diff --git a/mm/swap_state.c b/mm/swap_state.c index 7b09ac5..db8a3d3 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -27,6 +27,7 @@ static struct address_space_operations swap_aops = { .writepage = swap_writepage, .sync_page = block_sync_page, .set_page_dirty = __set_page_dirty_nobuffers, + .migratepage = migrate_page, }; static struct backing_dev_info swap_backing_dev_info = { diff --git a/mm/vmscan.c b/mm/vmscan.c index 5e98b86..5a61080 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -615,6 +615,15 @@ int putback_lru_pages(struct list_head *l) } /* + * Non migratable page + */ +int fail_migrate_page(struct page *newpage, struct page *page) +{ + return -EIO; +} +EXPORT_SYMBOL(fail_migrate_page); + +/* * swapout a single page * page is locked upon entry, unlocked on exit */ @@ -659,6 +668,7 @@ unlock_retry: retry: return -EAGAIN; } +EXPORT_SYMBOL(swap_page); /* * Page migration was first developed in the context of the memory hotplug @@ -674,7 +684,7 @@ retry: * Remove references for a page and establish the new page with the correct * basic settings to be able to stop accesses to the page. */ -static int migrate_page_remove_references(struct page *newpage, +int migrate_page_remove_references(struct page *newpage, struct page *page, int nr_refs) { struct address_space *mapping = page_mapping(page); @@ -749,6 +759,7 @@ static int migrate_page_remove_references(struct page *newpage, return 0; } +EXPORT_SYMBOL(migrate_page_remove_references); /* * Copy the page to its new location @@ -788,6 +799,7 @@ void migrate_page_copy(struct page *newpage, struct page *page) if (PageWriteback(newpage)) end_page_writeback(newpage); } +EXPORT_SYMBOL(migrate_page_copy); /* * Common logic to directly migrate a single page suitable for @@ -815,6 +827,7 @@ int migrate_page(struct page *newpage, struct page *page) remove_from_swap(newpage); return 0; } +EXPORT_SYMBOL(migrate_page); /* * migrate_pages @@ -914,6 +927,11 @@ redo: if (!mapping) goto unlock_both; + if (mapping->a_ops->migratepage) { + rc = mapping->a_ops->migratepage(newpage, page); + goto unlock_both; + } + /* * Trigger writeout if page is dirty */ |