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authorJens Axboe <axboe@kernel.dk>2019-07-01 17:16:08 +0300
committerJens Axboe <axboe@kernel.dk>2019-07-01 17:16:08 +0300
commit5be1f9d82fa73c199ebeee2866dbac83e419c897 (patch)
treeaed1aec34f40b5e0f36dceea8b58d9cfdb41d233 /block
parentff91064ea37c8323eba31cc3d2e22464f107b50d (diff)
parent4b972a01a7da614b4796475f933094751a295a2f (diff)
downloadlinux-5be1f9d82fa73c199ebeee2866dbac83e419c897.tar.xz
Merge tag 'v5.2-rc6' into for-5.3/block
Merge 5.2-rc6 into for-5.3/block, so we get the same page merge leak fix. Otherwise we end up having conflicts with future patches between for-5.3/block and master that touch this area. In particular, it makes the bio_full() fix hard to backport to stable. * tag 'v5.2-rc6': (482 commits) Linux 5.2-rc6 Revert "iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock" Bluetooth: Fix regression with minimum encryption key size alignment tcp: refine memory limit test in tcp_fragment() x86/vdso: Prevent segfaults due to hoisted vclock reads SUNRPC: Fix a credential refcount leak Revert "SUNRPC: Declare RPC timers as TIMER_DEFERRABLE" net :sunrpc :clnt :Fix xps refcount imbalance on the error path NFS4: Only set creation opendata if O_CREAT ARM: 8867/1: vdso: pass --be8 to linker if necessary KVM: nVMX: reorganize initial steps of vmx_set_nested_state KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries habanalabs: use u64_to_user_ptr() for reading user pointers nfsd: replace Jeff by Chuck as nfsd co-maintainer inet: clear num_timeout reqsk_alloc() PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present net: mvpp2: debugfs: Add pmap to fs dump ipv6: Default fib6_type to RTN_UNICAST when not set net: hns3: Fix inconsistent indenting net/af_iucv: always register net_device notifier ...
Diffstat (limited to 'block')
-rw-r--r--block/bio.c38
1 files changed, 21 insertions, 17 deletions
diff --git a/block/bio.c b/block/bio.c
index 5733b9426231..933c1e36643b 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -628,7 +628,7 @@ EXPORT_SYMBOL(bio_clone_fast);
static inline bool page_is_mergeable(const struct bio_vec *bv,
struct page *page, unsigned int len, unsigned int off,
- bool same_page)
+ bool *same_page)
{
phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +
bv->bv_offset + bv->bv_len - 1;
@@ -639,15 +639,9 @@ static inline bool page_is_mergeable(const struct bio_vec *bv,
if (xen_domain() && !xen_biovec_phys_mergeable(bv, page))
return false;
- if ((vec_end_addr & PAGE_MASK) != page_addr) {
- if (same_page)
- return false;
- if (pfn_to_page(PFN_DOWN(vec_end_addr)) + 1 != page)
- return false;
- }
-
- WARN_ON_ONCE(same_page && (len + off) > PAGE_SIZE);
-
+ *same_page = ((vec_end_addr & PAGE_MASK) == page_addr);
+ if (!*same_page && pfn_to_page(PFN_DOWN(vec_end_addr)) + 1 != page)
+ return false;
return true;
}
@@ -693,6 +687,7 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
bool put_same_page)
{
struct bio_vec *bvec;
+ bool same_page = false;
/*
* cloned bio must not modify vec list
@@ -721,7 +716,7 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
if (bvec_gap_to_prev(q, bvec, offset))
return 0;
- if (page_is_mergeable(bvec, page, len, offset, false) &&
+ if (page_is_mergeable(bvec, page, len, offset, &same_page) &&
can_add_page_to_seg(q, bvec, page, len, offset)) {
bvec->bv_len += len;
goto done;
@@ -757,8 +752,7 @@ EXPORT_SYMBOL(bio_add_pc_page);
* @page: start page to add
* @len: length of the data to add
* @off: offset of the data relative to @page
- * @same_page: if %true only merge if the new data is in the same physical
- * page as the last segment of the bio.
+ * @same_page: return if the segment has been merged inside the same page
*
* Try to add the data at @page + @off to the last bvec of @bio. This is a
* a useful optimisation for file systems with a block size smaller than the
@@ -769,7 +763,7 @@ EXPORT_SYMBOL(bio_add_pc_page);
* Return %true on success or %false on failure.
*/
bool __bio_try_merge_page(struct bio *bio, struct page *page,
- unsigned int len, unsigned int off, bool same_page)
+ unsigned int len, unsigned int off, bool *same_page)
{
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
return false;
@@ -827,7 +821,9 @@ EXPORT_SYMBOL_GPL(__bio_add_page);
int bio_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
- if (!__bio_try_merge_page(bio, page, len, offset, false)) {
+ bool same_page = false;
+
+ if (!__bio_try_merge_page(bio, page, len, offset, &same_page)) {
if (bio_full(bio))
return 0;
__bio_add_page(bio, page, len, offset);
@@ -887,6 +883,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
struct page **pages = (struct page **)bv;
+ bool same_page = false;
ssize_t size, left;
unsigned len, i;
size_t offset;
@@ -907,8 +904,15 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
struct page *page = pages[i];
len = min_t(size_t, PAGE_SIZE - offset, left);
- if (WARN_ON_ONCE(bio_add_page(bio, page, len, offset) != len))
- return -EINVAL;
+
+ if (__bio_try_merge_page(bio, page, len, offset, &same_page)) {
+ if (same_page)
+ put_page(page);
+ } else {
+ if (WARN_ON_ONCE(bio_full(bio)))
+ return -EINVAL;
+ __bio_add_page(bio, page, len, offset);
+ }
offset = 0;
}