From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tsutomu Itoh Subject: Re: [PATCH] fix uncheck memory allocations Date: Mon, 14 Feb 2011 08:57:34 +0900 Message-ID: <4D586FEE.9040501@jp.fujitsu.com> References: <1297509433-15183-1-git-send-email-yoshinori.sano@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Cc: linux-btrfs@vger.kernel.org To: Yoshinori Sano Return-path: In-Reply-To: <1297509433-15183-1-git-send-email-yoshinori.sano@gmail.com> List-ID: (2011/02/12 20:17), Yoshinori Sano wrote: > To make Btrfs code more robust, several return value checks where memory > allocation can fail are introduced. I use BUG_ON where I don't know how > to handle the error properly, which increases the number of using the > notorious BUG_ON, though. > > Signed-off-by: Yoshinori Sano > --- > fs/btrfs/compression.c | 6 ++++++ > fs/btrfs/extent-tree.c | 2 ++ > fs/btrfs/file.c | 8 ++++++-- > fs/btrfs/inode.c | 5 +++++ > 4 files changed, 19 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c > index 4d2110e..f596554 100644 > --- a/fs/btrfs/compression.c > +++ b/fs/btrfs/compression.c > @@ -340,6 +340,8 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, > > WARN_ON(start & ((u64)PAGE_CACHE_SIZE - 1)); > cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS); > + if (!cb) > + return -ENOMEM; > atomic_set(&cb->pending_bios, 0); > cb->errors = 0; > cb->inode = inode; > @@ -354,6 +356,10 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, > bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; > > bio = compressed_bio_alloc(bdev, first_byte, GFP_NOFS); > + if (!bio) { > + kfree(cb); > + return -ENOMEM; > + } > bio->bi_private = cb; > bio->bi_end_io = end_compressed_bio_write; > atomic_inc(&cb->pending_bios); > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 565e22d..aed16f4 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -6931,6 +6931,8 @@ static noinline int get_new_locations(struct inode *reloc_inode, > struct disk_extent *old = exts; > max *= 2; > exts = kzalloc(sizeof(*exts) * max, GFP_NOFS); > + if (!exts) > + goto out; > memcpy(exts, old, sizeof(*exts) * nr); > if (old != *extents) > kfree(old); > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index b0ff34b..4895ad2 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -181,10 +181,14 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, > testend = 0; > } > while (1) { > - if (!split) > + if (!split) { > split = alloc_extent_map(GFP_NOFS); > - if (!split2) > + BUG_ON(!split || IS_ERR(split)); alloc_extent_map() returns only the address or NULL. Therefore, I think that check by IS_ERR() is unnecessary. Regards, Itoh > + } > + if (!split2) { > split2 = alloc_extent_map(GFP_NOFS); > + BUG_ON(!split2 || IS_ERR(split2)); > + } > > write_lock(&em_tree->lock); > em = lookup_extent_mapping(em_tree, start, len); > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index c9bc0af..40bbe00 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -287,6 +287,7 @@ static noinline int add_async_extent(struct async_cow *cow, > struct async_extent *async_extent; > > async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); > + BUG_ON(!async_extent); > async_extent->start = start; > async_extent->ram_size = ram_size; > async_extent->compressed_size = compressed_size; > @@ -384,6 +385,7 @@ again: > (BTRFS_I(inode)->force_compress))) { > WARN_ON(pages); > pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); > + BUG_ON(!pages); > > if (BTRFS_I(inode)->force_compress) > compress_type = BTRFS_I(inode)->force_compress; > @@ -644,6 +646,7 @@ retry: > async_extent->ram_size - 1, 0); > > em = alloc_extent_map(GFP_NOFS); > + BUG_ON(!em || IS_ERR(em)); > em->start = async_extent->start; > em->len = async_extent->ram_size; > em->orig_start = em->start; > @@ -820,6 +823,7 @@ static noinline int cow_file_range(struct inode *inode, > BUG_ON(ret); > > em = alloc_extent_map(GFP_NOFS); > + BUG_ON(!em || IS_ERR(em)); > em->start = start; > em->orig_start = em->start; > ram_size = ins.offset; > @@ -1169,6 +1173,7 @@ out_check: > struct extent_map_tree *em_tree; > em_tree = &BTRFS_I(inode)->extent_tree; > em = alloc_extent_map(GFP_NOFS); > + BUG_ON(!em || IS_ERR(em)); > em->start = cur_offset; > em->orig_start = em->start; > em->len = num_bytes;