diff options
| -rw-r--r-- | fs/btrfs/extent_io.c | 69 | ||||
| -rw-r--r-- | fs/btrfs/subpage.c | 30 | ||||
| -rw-r--r-- | fs/btrfs/subpage.h | 10 |
3 files changed, 96 insertions, 13 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d3819dde8952..e498d496560b 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -24,6 +24,7 @@ #include "rcu-string.h" #include "backref.h" #include "disk-io.h" +#include "subpage.h" static struct kmem_cache *extent_state_cache; static struct kmem_cache *extent_buffer_cache; @@ -3141,9 +3142,13 @@ static int submit_extent_page(unsigned int opf, return ret; } -static void attach_extent_buffer_page(struct extent_buffer *eb, - struct page *page) +static int attach_extent_buffer_page(struct extent_buffer *eb, + struct page *page, + struct btrfs_subpage *prealloc) { + struct btrfs_fs_info *fs_info = eb->fs_info; + int ret = 0; + /* * If the page is mapped to btree inode, we should hold the private * lock to prevent race. @@ -3153,10 +3158,28 @@ static void attach_extent_buffer_page(struct extent_buffer *eb, if (page->mapping) lockdep_assert_held(&page->mapping->private_lock); - if (!PagePrivate(page)) - attach_page_private(page, eb); + if (fs_info->sectorsize == PAGE_SIZE) { + if (!PagePrivate(page)) + attach_page_private(page, eb); + else + WARN_ON(page->private != (unsigned long)eb); + return 0; + } + + /* Already mapped, just free prealloc */ + if (PagePrivate(page)) { + btrfs_free_subpage(prealloc); + return 0; + } + + if (prealloc) + /* Has preallocated memory for subpage */ + attach_page_private(page, prealloc); else - WARN_ON(page->private != (unsigned long)eb); + /* Do new allocation to attach subpage */ + ret = btrfs_attach_subpage(fs_info, page, + BTRFS_SUBPAGE_METADATA); + return ret; } void set_page_extent_mapped(struct page *page) @@ -5072,12 +5095,19 @@ struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src) set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags); for (i = 0; i < num_pages; i++) { + int ret; + p = alloc_page(GFP_NOFS); if (!p) { btrfs_release_extent_buffer(new); return NULL; } - attach_extent_buffer_page(new, p); + ret = attach_extent_buffer_page(new, p, NULL); + if (ret < 0) { + put_page(p); + btrfs_release_extent_buffer(new); + return NULL; + } WARN_ON(PageDirty(p)); SetPageUptodate(p); new->pages[i] = p; @@ -5315,12 +5345,33 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, num_pages = num_extent_pages(eb); for (i = 0; i < num_pages; i++, index++) { + struct btrfs_subpage *prealloc = NULL; + p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL); if (!p) { exists = ERR_PTR(-ENOMEM); goto free_eb; } + /* + * Preallocate page->private for subpage case, so that we won't + * allocate memory with private_lock hold. The memory will be + * freed by attach_extent_buffer_page() or freed manually if + * we exit earlier. + * + * Although we have ensured one subpage eb can only have one + * page, but it may change in the future for 16K page size + * support, so we still preallocate the memory in the loop. + */ + ret = btrfs_alloc_subpage(fs_info, &prealloc, + BTRFS_SUBPAGE_METADATA); + if (ret < 0) { + unlock_page(p); + put_page(p); + exists = ERR_PTR(ret); + goto free_eb; + } + spin_lock(&mapping->private_lock); exists = grab_extent_buffer(p); if (exists) { @@ -5328,10 +5379,14 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, unlock_page(p); put_page(p); mark_extent_buffer_accessed(exists, p); + btrfs_free_subpage(prealloc); goto free_eb; } - attach_extent_buffer_page(eb, p); + /* Should not fail, as we have preallocated the memory */ + ret = attach_extent_buffer_page(eb, p, prealloc); + ASSERT(!ret); spin_unlock(&mapping->private_lock); + WARN_ON(PageDirty(p)); eb->pages[i] = p; if (!PageUptodate(p)) diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index a3e5b6a13d54..61b28dfca20c 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -7,7 +7,8 @@ int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info, struct page *page, enum btrfs_subpage_type type) { - struct btrfs_subpage *subpage; + struct btrfs_subpage *subpage = NULL; + int ret; /* * We have cases like a dummy extent buffer page, which is not mappped @@ -19,11 +20,9 @@ int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info, if (fs_info->sectorsize == PAGE_SIZE || PagePrivate(page)) return 0; - subpage = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS); - if (!subpage) - return -ENOMEM; - - spin_lock_init(&subpage->lock); + ret = btrfs_alloc_subpage(fs_info, &subpage, type); + if (ret < 0) + return ret; attach_page_private(page, subpage); return 0; } @@ -39,5 +38,24 @@ void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, subpage = (struct btrfs_subpage *)detach_page_private(page); ASSERT(subpage); + btrfs_free_subpage(subpage); +} + +int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info, + struct btrfs_subpage **ret, + enum btrfs_subpage_type type) +{ + if (fs_info->sectorsize == PAGE_SIZE) + return 0; + + *ret = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS); + if (!*ret) + return -ENOMEM; + spin_lock_init(&(*ret)->lock); + return 0; +} + +void btrfs_free_subpage(struct btrfs_subpage *subpage) +{ kfree(subpage); } diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index 676280bc7562..7ba544bcc9c6 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -18,6 +18,10 @@ struct btrfs_subpage { /* Common members for both data and metadata pages */ spinlock_t lock; + union { + /* Structures only used by metadata */ + /* Structures only used by data */ + }; }; enum btrfs_subpage_type { @@ -30,4 +34,10 @@ int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info, void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, struct page *page); +/* Allocate additional data where page represents more than one sector */ +int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info, + struct btrfs_subpage **ret, + enum btrfs_subpage_type type); +void btrfs_free_subpage(struct btrfs_subpage *subpage); + #endif |