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| author |   Gao Xiang <gaoxiang25@huawei.com> | 2019-10-31 17:23:15 +0800 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2019-11-14 22:19:11 -0500 |
| commit | 5500221ea1b72c550b61f88fe3e8afbb08445989 (patch) | |
| tree | abff9db3e85a302c51438e7b1ff83c5054a3d229 /fs/ext4/readpage.c | |
| parent | ext4: code cleanup for get_next_id (diff) | |
| download | wireguard-linux-5500221ea1b72c550b61f88fe3e8afbb08445989.tar.xz wireguard-linux-5500221ea1b72c550b61f88fe3e8afbb08445989.zip | |
ext4: bio_alloc with __GFP_DIRECT_RECLAIM never fails
Similar to [1] [2], bio_alloc with __GFP_DIRECT_RECLAIM flags
guarantees bio allocation under some given restrictions, as
stated in block/bio.c and fs/direct-io.c So here it's ok to
not check for NULL value from bio_alloc().
[1] https://lore.kernel.org/r/20191030035518.65477-1-gaoxiang25@huawei.com
[2] https://lore.kernel.org/r/20190830162812.GA10694@infradead.org
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20191031092315.139267-1-gaoxiang25@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/readpage.c')
| -rw-r--r-- | fs/ext4/readpage.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c index a30b203fa461..fef7755300c3 100644 --- a/fs/ext4/readpage.c +++ b/fs/ext4/readpage.c @@ -360,10 +360,12 @@ int ext4_mpage_readpages(struct address_space *mapping, if (bio == NULL) { struct bio_post_read_ctx *ctx; + /* + * bio_alloc will _always_ be able to allocate a bio if + * __GFP_DIRECT_RECLAIM is set, see bio_alloc_bioset(). + */ bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES)); - if (!bio) - goto set_error_page; ctx = get_bio_post_read_ctx(inode, bio, page->index); if (IS_ERR(ctx)) { bio_put(bio); |