2011年2月15日9:14 Tsutomu Itoh <t-itoh@xxxxxxxxxxxxxx>:
> Sano-san,
>
> (2011/02/14 22:57), Yoshinori Sano wrote:
>> 2011年2月14日8:57 Tsutomu Itoh <t-itoh@xxxxxxxxxxxxxx>:
>>> (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 <yoshinori.sano@xxxxxxxxx>
>>>> ---
>>>> 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;
>
> 'ret = -ENOMEM' is necessary before 'goto out'.
I'll keep in mind to fix this too.
>
>>>> 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
>>
>> Exactly. IS_ERR is not required.
>> I should read the alloc_extent_map' s implementation more deeply.
>> Thank you.
>
> Could you please merge my patch(http://marc.info/?l=linux-btrfs&m=129764438122741&w=2)
> with your patch, and post it again?
Yes, this is a good idea :)
I'll merge your patch and post it again later.
Thank you.
>
> Thanks,
> 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;
>>>
>>>
>>
>
>
--
Yoshinori Sano <yoshinori.sano@xxxxxxxxx>
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