Since we have a helper to set page bits, let lock_delalloc_pages and __unlock_for_delalloc use it.
Signed-off-by: Liu Bo <[email protected]> --- fs/btrfs/extent_io.c | 122 ++++++++++++++++++++++----------------------------- fs/btrfs/extent_io.h | 3 +- 2 files changed, 54 insertions(+), 71 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 2ef2d05..7e9639f 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1549,33 +1549,24 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree, return found; } +static int __process_pages_contig(struct address_space *mapping, + struct page *locked_page, + pgoff_t start_index, pgoff_t end_index, + unsigned long page_ops, pgoff_t *index_ret); + static noinline void __unlock_for_delalloc(struct inode *inode, struct page *locked_page, u64 start, u64 end) { - int ret; - struct page *pages[16]; unsigned long index = start >> PAGE_SHIFT; unsigned long end_index = end >> PAGE_SHIFT; - unsigned long nr_pages = end_index - index + 1; - int i; + ASSERT(locked_page); if (index == locked_page->index && end_index == index) return; - while (nr_pages > 0) { - ret = find_get_pages_contig(inode->i_mapping, index, - min_t(unsigned long, nr_pages, - ARRAY_SIZE(pages)), pages); - for (i = 0; i < ret; i++) { - if (pages[i] != locked_page) - unlock_page(pages[i]); - put_page(pages[i]); - } - nr_pages -= ret; - index += ret; - cond_resched(); - } + __process_pages_contig(inode->i_mapping, locked_page, index, end_index, + PAGE_UNLOCK, NULL); } static noinline int lock_delalloc_pages(struct inode *inode, @@ -1584,59 +1575,19 @@ static noinline int lock_delalloc_pages(struct inode *inode, u64 delalloc_end) { unsigned long index = delalloc_start >> PAGE_SHIFT; - unsigned long start_index = index; + unsigned long index_ret = index; unsigned long end_index = delalloc_end >> PAGE_SHIFT; - unsigned long pages_locked = 0; - struct page *pages[16]; - unsigned long nrpages; int ret; - int i; - /* the caller is responsible for locking the start index */ + ASSERT(locked_page); if (index == locked_page->index && index == end_index) return 0; - /* skip the page at the start index */ - nrpages = end_index - index + 1; - while (nrpages > 0) { - ret = find_get_pages_contig(inode->i_mapping, index, - min_t(unsigned long, - nrpages, ARRAY_SIZE(pages)), pages); - if (ret == 0) { - ret = -EAGAIN; - goto done; - } - /* now we have an array of pages, lock them all */ - for (i = 0; i < ret; i++) { - /* - * the caller is taking responsibility for - * locked_page - */ - if (pages[i] != locked_page) { - lock_page(pages[i]); - if (!PageDirty(pages[i]) || - pages[i]->mapping != inode->i_mapping) { - ret = -EAGAIN; - unlock_page(pages[i]); - put_page(pages[i]); - goto done; - } - } - put_page(pages[i]); - pages_locked++; - } - nrpages -= ret; - index += ret; - cond_resched(); - } - ret = 0; -done: - if (ret && pages_locked) { - __unlock_for_delalloc(inode, locked_page, - delalloc_start, - ((u64)(start_index + pages_locked - 1)) << - PAGE_SHIFT); - } + ret = __process_pages_contig(inode->i_mapping, locked_page, index, + end_index, PAGE_LOCK, &index_ret); + if (ret == -EAGAIN) + __unlock_for_delalloc(inode, locked_page, delalloc_start, + (u64)index_ret << PAGE_SHIFT); return ret; } @@ -1726,17 +1677,24 @@ STATIC u64 find_lock_delalloc_range(struct inode *inode, return found; } -static void __process_pages_contig(struct address_space *mapping, - struct page *locked_page, - pgoff_t start_index, pgoff_t end_index, - unsigned long page_ops) +static int __process_pages_contig(struct address_space *mapping, + struct page *locked_page, + pgoff_t start_index, pgoff_t end_index, + unsigned long page_ops, pgoff_t *index_ret) { unsigned long nr_pages = end_index - start_index + 1; + unsigned long pages_locked = 0; pgoff_t index = start_index; struct page *pages[16]; unsigned ret; + int err = 0; int i; + if (page_ops & PAGE_LOCK) { + ASSERT(page_ops == PAGE_LOCK); + ASSERT(index_ret && *index_ret == start_index); + } + if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0) mapping_set_error(mapping, -EIO); @@ -1744,13 +1702,22 @@ static void __process_pages_contig(struct address_space *mapping, ret = find_get_pages_contig(mapping, index, min_t(unsigned long, nr_pages, ARRAY_SIZE(pages)), pages); - for (i = 0; i < ret; i++) { + if (ret == 0) { + /* + * Only if we're going to lock these pages, + * can we find nothing at @index. + */ + ASSERT(page_ops & PAGE_LOCK); + return ret; + } + for (i = 0; i < ret; i++) { if (page_ops & PAGE_SET_PRIVATE2) SetPagePrivate2(pages[i]); if (pages[i] == locked_page) { put_page(pages[i]); + pages_locked++; continue; } if (page_ops & PAGE_CLEAR_DIRTY) @@ -1763,12 +1730,27 @@ static void __process_pages_contig(struct address_space *mapping, end_page_writeback(pages[i]); if (page_ops & PAGE_UNLOCK) unlock_page(pages[i]); + if (page_ops & PAGE_LOCK) { + lock_page(pages[i]); + if (!PageDirty(pages[i]) || + pages[i]->mapping != mapping) { + unlock_page(pages[i]); + put_page(pages[i]); + err = -EAGAIN; + goto out; + } + } put_page(pages[i]); + pages_locked++; } nr_pages -= ret; index += ret; cond_resched(); } +out: + if (err && index_ret) + *index_ret = start_index + pages_locked - 1; + return err; } void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, @@ -1781,7 +1763,7 @@ void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, __process_pages_contig(inode->i_mapping, locked_page, start >> PAGE_SHIFT, end >> PAGE_SHIFT, - page_ops); + page_ops, NULL); } /* diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 17f9ce4..4551a5b 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -45,13 +45,14 @@ #define EXTENT_BUFFER_IN_TREE 10 #define EXTENT_BUFFER_WRITE_ERR 11 /* write IO error */ -/* these are flags for extent_clear_unlock_delalloc */ +/* these are flags for __process_pages_contig */ #define PAGE_UNLOCK (1 << 0) #define PAGE_CLEAR_DIRTY (1 << 1) #define PAGE_SET_WRITEBACK (1 << 2) #define PAGE_END_WRITEBACK (1 << 3) #define PAGE_SET_PRIVATE2 (1 << 4) #define PAGE_SET_ERROR (1 << 5) +#define PAGE_LOCK (1 << 6) /* * page->private values. Every page that is controlled by the extent -- 2.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
