diff options
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/compression.c | 33 | ||||
| -rw-r--r-- | fs/btrfs/compression.h | 4 | ||||
| -rw-r--r-- | fs/btrfs/ctree.c | 14 | ||||
| -rw-r--r-- | fs/btrfs/locking.c | 24 | ||||
| -rw-r--r-- | fs/btrfs/locking.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/lzo.c | 15 | ||||
| -rw-r--r-- | fs/btrfs/zlib.c | 20 |
7 files changed, 92 insertions, 20 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index d3220d31d3cb..dcd9be32ac57 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -1011,8 +1011,6 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, bytes = min(bytes, working_bytes); kaddr = kmap_atomic(page_out); memcpy(kaddr + *pg_offset, buf + buf_offset, bytes); - if (*pg_index == (vcnt - 1) && *pg_offset == 0) - memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes); kunmap_atomic(kaddr); flush_dcache_page(page_out); @@ -1054,3 +1052,34 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, return 1; } + +/* + * When uncompressing data, we need to make sure and zero any parts of + * the biovec that were not filled in by the decompression code. pg_index + * and pg_offset indicate the last page and the last offset of that page + * that have been filled in. This will zero everything remaining in the + * biovec. + */ +void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt, + unsigned long pg_index, + unsigned long pg_offset) +{ + while (pg_index < vcnt) { + struct page *page = bvec[pg_index].bv_page; + unsigned long off = bvec[pg_index].bv_offset; + unsigned long len = bvec[pg_index].bv_len; + + if (pg_offset < off) + pg_offset = off; + if (pg_offset < off + len) { + unsigned long bytes = off + len - pg_offset; + char *kaddr; + + kaddr = kmap_atomic(page); + memset(kaddr + pg_offset, 0, bytes); + kunmap_atomic(kaddr); + } + pg_index++; + pg_offset = 0; + } +} diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 0c803b4fbf93..d181f70caae0 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -45,7 +45,9 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, unsigned long nr_pages); int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, int mirror_num, unsigned long bio_flags); - +void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt, + unsigned long pg_index, + unsigned long pg_offset); struct btrfs_compress_op { struct list_head *(*alloc_workspace)(void); diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 19bc6162fb8e..150822ee0a0b 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -80,13 +80,6 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, { int i; -#ifdef CONFIG_DEBUG_LOCK_ALLOC - /* lockdep really cares that we take all of these spinlocks - * in the right order. If any of the locks in the path are not - * currently blocking, it is going to complain. So, make really - * really sure by forcing the path to blocking before we clear - * the path blocking. - */ if (held) { btrfs_set_lock_blocking_rw(held, held_rw); if (held_rw == BTRFS_WRITE_LOCK) @@ -95,7 +88,6 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, held_rw = BTRFS_READ_LOCK_BLOCKING; } btrfs_set_path_blocking(p); -#endif for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { if (p->nodes[i] && p->locks[i]) { @@ -107,10 +99,8 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, } } -#ifdef CONFIG_DEBUG_LOCK_ALLOC if (held) btrfs_clear_lock_blocking_rw(held, held_rw); -#endif } /* this also releases the path */ @@ -2893,7 +2883,7 @@ cow_done: } p->locks[level] = BTRFS_WRITE_LOCK; } else { - err = btrfs_try_tree_read_lock(b); + err = btrfs_tree_read_lock_atomic(b); if (!err) { btrfs_set_path_blocking(p); btrfs_tree_read_lock(b); @@ -3025,7 +3015,7 @@ again: } level = btrfs_header_level(b); - err = btrfs_try_tree_read_lock(b); + err = btrfs_tree_read_lock_atomic(b); if (!err) { btrfs_set_path_blocking(p); btrfs_tree_read_lock(b); diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 5665d2149249..f8229ef1b46d 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -128,6 +128,26 @@ again: } /* + * take a spinning read lock. + * returns 1 if we get the read lock and 0 if we don't + * this won't wait for blocking writers + */ +int btrfs_tree_read_lock_atomic(struct extent_buffer *eb) +{ + if (atomic_read(&eb->blocking_writers)) + return 0; + + read_lock(&eb->lock); + if (atomic_read(&eb->blocking_writers)) { + read_unlock(&eb->lock); + return 0; + } + atomic_inc(&eb->read_locks); + atomic_inc(&eb->spinning_readers); + return 1; +} + +/* * returns 1 if we get the read lock and 0 if we don't * this won't wait for blocking writers */ @@ -158,9 +178,7 @@ int btrfs_try_tree_write_lock(struct extent_buffer *eb) atomic_read(&eb->blocking_readers)) return 0; - if (!write_trylock(&eb->lock)) - return 0; - + write_lock(&eb->lock); if (atomic_read(&eb->blocking_writers) || atomic_read(&eb->blocking_readers)) { write_unlock(&eb->lock); diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h index b81e0e9a4894..c44a9d5f5362 100644 --- a/fs/btrfs/locking.h +++ b/fs/btrfs/locking.h @@ -35,6 +35,8 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw); void btrfs_assert_tree_locked(struct extent_buffer *eb); int btrfs_try_tree_read_lock(struct extent_buffer *eb); int btrfs_try_tree_write_lock(struct extent_buffer *eb); +int btrfs_tree_read_lock_atomic(struct extent_buffer *eb); + static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw) { diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 78285f30909e..617553cdb7d3 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -373,6 +373,8 @@ cont: } done: kunmap(pages_in[page_in_index]); + if (!ret) + btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset); return ret; } @@ -410,10 +412,23 @@ static int lzo_decompress(struct list_head *ws, unsigned char *data_in, goto out; } + /* + * the caller is already checking against PAGE_SIZE, but lets + * move this check closer to the memcpy/memset + */ + destlen = min_t(unsigned long, destlen, PAGE_SIZE); bytes = min_t(unsigned long, destlen, out_len - start_byte); kaddr = kmap_atomic(dest_page); memcpy(kaddr, workspace->buf + start_byte, bytes); + + /* + * btrfs_getblock is doing a zero on the tail of the page too, + * but this will cover anything missing from the decompressed + * data. + */ + if (bytes < destlen) + memset(kaddr+bytes, 0, destlen-bytes); kunmap_atomic(kaddr); out: return ret; diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 759fa4e2de8f..fb22fd8d8fb8 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -299,6 +299,8 @@ done: zlib_inflateEnd(&workspace->strm); if (data_in) kunmap(pages_in[page_in_index]); + if (!ret) + btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset); return ret; } @@ -310,10 +312,14 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, struct workspace *workspace = list_entry(ws, struct workspace, list); int ret = 0; int wbits = MAX_WBITS; - unsigned long bytes_left = destlen; + unsigned long bytes_left; unsigned long total_out = 0; + unsigned long pg_offset = 0; char *kaddr; + destlen = min_t(unsigned long, destlen, PAGE_SIZE); + bytes_left = destlen; + workspace->strm.next_in = data_in; workspace->strm.avail_in = srclen; workspace->strm.total_in = 0; @@ -341,7 +347,6 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, unsigned long buf_start; unsigned long buf_offset; unsigned long bytes; - unsigned long pg_offset = 0; ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) @@ -384,6 +389,17 @@ next: ret = 0; zlib_inflateEnd(&workspace->strm); + + /* + * this should only happen if zlib returned fewer bytes than we + * expected. btrfs_get_block is responsible for zeroing from the + * end of the inline extent (destlen) to the end of the page + */ + if (pg_offset < destlen) { + kaddr = kmap_atomic(dest_page); + memset(kaddr + pg_offset, 0, destlen - pg_offset); + kunmap_atomic(kaddr); + } return ret; } |