From 14048ed0c415b8729b194e92c16d31c61628d216 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 15 Oct 2007 16:16:28 -0400 Subject: [PATCH] Btrfs: Cache extent buffer mappings Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 40 ++++++++++++++++++++++++++++++++++++---- fs/btrfs/extent_map.c | 15 +++++++++++++-- 2 files changed, 49 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 4d05456ec32f..54c754dd9a14 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -436,10 +436,18 @@ static inline u##bits btrfs_##name(struct extent_buffer *eb, \ unsigned long map_len; \ unsigned long offset = (unsigned long)s + \ offsetof(type, member); \ - err = map_extent_buffer(eb, offset, \ + if (eb->map_token && offset >= eb->map_start && \ + offset + sizeof(((type *)0)->member) <= eb->map_start + \ + eb->map_len) { \ + kaddr = eb->kaddr; \ + map_start = eb->map_start; \ + err = 0; \ + } else { \ + err = map_extent_buffer(eb, offset, \ sizeof(((type *)0)->member), \ &map_token, &kaddr, \ &map_start, &map_len, KM_USER1); \ + } \ if (!err) { \ __le##bits *tmp = (__le##bits *)(kaddr + offset - \ map_start); \ @@ -464,10 +472,18 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ int unmap_on_exit = (eb->map_token == NULL); \ unsigned long offset = (unsigned long)s + \ offsetof(type, member); \ - err = map_extent_buffer(eb, offset, \ + if (eb->map_token && offset >= eb->map_start && \ + offset + sizeof(((type *)0)->member) <= eb->map_start + \ + eb->map_len) { \ + kaddr = eb->kaddr; \ + map_start = eb->map_start; \ + err = 0; \ + } else { \ + err = map_extent_buffer(eb, offset, \ sizeof(((type *)0)->member), \ &map_token, &kaddr, \ &map_start, &map_len, KM_USER1); \ + } \ if (!err) { \ __le##bits *tmp = (__le##bits *)(kaddr + offset - \ map_start); \ @@ -490,10 +506,18 @@ static inline u##bits btrfs_##name(struct extent_buffer *eb) \ unsigned long map_len; \ unsigned long offset = offsetof(type, member); \ int unmap_on_exit = (eb->map_token == NULL); \ - err = map_extent_buffer(eb, offset, \ + if (eb->map_token && offset >= eb->map_start && \ + offset + sizeof(((type *)0)->member) <= eb->map_start + \ + eb->map_len) { \ + kaddr = eb->kaddr; \ + map_start = eb->map_start; \ + err = 0; \ + } else { \ + err = map_extent_buffer(eb, offset, \ sizeof(((type *)0)->member), \ &map_token, &kaddr, \ &map_start, &map_len, KM_USER1); \ + } \ if (!err) { \ __le##bits *tmp = (__le##bits *)(kaddr + offset - \ map_start); \ @@ -517,10 +541,18 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ unsigned long map_len; \ unsigned long offset = offsetof(type, member); \ int unmap_on_exit = (eb->map_token == NULL); \ - err = map_extent_buffer(eb, offset, \ + if (eb->map_token && offset >= eb->map_start && \ + offset + sizeof(((type *)0)->member) <= eb->map_start + \ + eb->map_len) { \ + kaddr = eb->kaddr; \ + map_start = eb->map_start; \ + err = 0; \ + } else { \ + err = map_extent_buffer(eb, offset, \ sizeof(((type *)0)->member), \ &map_token, &kaddr, \ &map_start, &map_len, KM_USER1); \ + } \ if (!err) { \ __le##bits *tmp = (__le##bits *)(kaddr + offset - \ map_start); \ diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index f658703c42e6..ea6ee68ef53c 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -2037,6 +2037,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, struct extent_buffer *eb; struct page *p; struct address_space *mapping = tree->mapping; + int uptodate = 1; eb = __alloc_extent_buffer(mask); if (!eb || IS_ERR(eb)) @@ -2048,7 +2049,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, atomic_set(&eb->refs, 1); for (i = 0; i < num_pages; i++, index++) { - p = find_get_page(mapping, index); + p = find_lock_page(mapping, index); if (!p) { /* make sure the free only frees the pages we've * grabbed a reference on @@ -2060,7 +2061,12 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, set_page_extent_mapped(p); if (i == 0) eb->first_page = p; + if (!PageUptodate(p)) + uptodate = 0; + unlock_page(p); } + if (uptodate) + eb->flags |= EXTENT_UPTODATE; return eb; fail: free_extent_buffer(eb); @@ -2192,7 +2198,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree, if (eb->flags & EXTENT_UPTODATE) return 0; - if (test_range_bit(tree, eb->start, eb->start + eb->len - 1, + if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1, EXTENT_UPTODATE, 1)) { return 0; } @@ -2247,6 +2253,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, char *dst = (char *)dstv; size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1); unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT; + unsigned long num_pages = num_extent_pages(eb->start, eb->len); WARN_ON(start > eb->len); WARN_ON(start + len > eb->start + eb->len); @@ -2257,6 +2264,10 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, while(len > 0) { page = extent_buffer_page(eb, i); + if (!PageUptodate(page)) { + printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len); + WARN_ON(1); + } WARN_ON(!PageUptodate(page)); cur = min(len, (PAGE_CACHE_SIZE - offset));