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| author | Eric Biggers <ebiggers@google.com> | 2019-12-31 18:55:45 +0100 |
|---|---|---|
| committer | Eric Biggers <ebiggers@google.com> | 2020-01-14 22:28:05 +0100 |
| commit | 439bea104c3d212def0216aa8c0820872266c5b3 (patch) | |
| tree | 1de5689485baeaac6b66822c57a519021a203469 /fs/verity/verify.c | |
| parent | fs-verity: implement readahead of Merkle tree pages (diff) | |
| download | linux-439bea104c3d212def0216aa8c0820872266c5b3.tar.xz linux-439bea104c3d212def0216aa8c0820872266c5b3.zip | |
fs-verity: use mempool for hash requests
When initializing an fs-verity hash algorithm, also initialize a mempool
that contains a single preallocated hash request object. Then replace
the direct calls to ahash_request_alloc() and ahash_request_free() with
allocating and freeing from this mempool.
This eliminates the possibility of the allocation failing, which is
desirable for the I/O path.
This doesn't cause deadlocks because there's no case where multiple hash
requests are needed at a time to make forward progress.
Link: https://lore.kernel.org/r/20191231175545.20709-1-ebiggers@kernel.org
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Diffstat (limited to 'fs/verity/verify.c')
| -rw-r--r-- | fs/verity/verify.c | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/fs/verity/verify.c b/fs/verity/verify.c index 7fa561c343c2..e0cb62da3864 100644 --- a/fs/verity/verify.c +++ b/fs/verity/verify.c @@ -192,13 +192,12 @@ bool fsverity_verify_page(struct page *page) struct ahash_request *req; bool valid; - req = ahash_request_alloc(vi->tree_params.hash_alg->tfm, GFP_NOFS); - if (unlikely(!req)) - return false; + /* This allocation never fails, since it's mempool-backed. */ + req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); valid = verify_page(inode, vi, req, page, 0); - ahash_request_free(req); + fsverity_free_hash_request(vi->tree_params.hash_alg, req); return valid; } @@ -229,12 +228,8 @@ void fsverity_verify_bio(struct bio *bio) struct bvec_iter_all iter_all; unsigned long max_ra_pages = 0; - req = ahash_request_alloc(params->hash_alg->tfm, GFP_NOFS); - if (unlikely(!req)) { - bio_for_each_segment_all(bv, bio, iter_all) - SetPageError(bv->bv_page); - return; - } + /* This allocation never fails, since it's mempool-backed. */ + req = fsverity_alloc_hash_request(params->hash_alg, GFP_NOFS); if (bio->bi_opf & REQ_RAHEAD) { /* @@ -262,7 +257,7 @@ void fsverity_verify_bio(struct bio *bio) SetPageError(page); } - ahash_request_free(req); + fsverity_free_hash_request(params->hash_alg, req); } EXPORT_SYMBOL_GPL(fsverity_verify_bio); #endif /* CONFIG_BLOCK */ |