The commit is pushed to "branch-rh7-3.10.0-693.17.1.vz7.43.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.17.1.vz7.43.5
------>
commit 05026ad794b6f7012bb9e4e861a1f74b199750de
Author: Andrei Vagin <ava...@openvz.org>
Date: Thu Feb 15 17:34:48 2018 +0300
ploop: give aligned regions into fuse fallocate()
fuse fallocate() can have requirements about granularity and alignment
for regions. For exmple, vstorage requires that all regions have to
be aligned onto 4096.
A block device has optimal values of granularity and alignment for
discard requests, but it has to handle unaligned requests too.
Each block device has the discard_zeroes_data attribute, which say
whether a block device returns zero for discarded block or not.
If we set it to 1, unaligned parts has to be filled in with zeros,
otherwise we can ignore them.
Signed-off-by: Andrei Vagin <ava...@openvz.org>
---
drivers/block/ploop/io_kaio.c | 80 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 80 insertions(+)
diff --git a/drivers/block/ploop/io_kaio.c b/drivers/block/ploop/io_kaio.c
index 22037f143151..998ad7454a66 100644
--- a/drivers/block/ploop/io_kaio.c
+++ b/drivers/block/ploop/io_kaio.c
@@ -246,6 +246,80 @@ static size_t kaio_kreq_pack(struct kaio_req *kreq, int
*nr_segs,
return copy;
}
+static int kaio_fill_zero_submit(struct file *file,
+ struct ploop_request *preq, loff_t off, size_t size)
+{
+ struct page *zero_page = ZERO_PAGE(0);
+ int nr_segs = 1, err = -ENOMEM;
+ struct kaio_req *kreq;
+
+ BUG_ON(size > PAGE_SIZE);
+
+ if (size == 0)
+ return 0;
+
+ kreq = kaio_kreq_alloc(preq, &nr_segs);
+ if (!kreq) {
+ PLOOP_REQ_SET_ERROR(preq, -ENOMEM);
+ return err;
+ }
+
+ kreq->bvecs[0].bv_page = zero_page;
+ kreq->bvecs[0].bv_len = size;
+ kreq->bvecs[0].bv_offset = 0;
+ atomic_inc(&preq->io_count);
+
+ err = kaio_kernel_submit(file, kreq, 1, size, off, REQ_WRITE);
+ if (err) {
+ PLOOP_REQ_SET_ERROR(preq, err);
+ ploop_complete_io_request(preq);
+ kfree(kreq);
+ return err;
+ }
+
+ return 0;
+}
+
+static int preprocess_discard_req(struct file *file, struct ploop_request
*preq,
+ loff_t *poff, size_t *psize)
+{
+ unsigned int alignment, granularity, zeroes_data;
+ loff_t off = *poff, off_align;
+ size_t size = *psize;
+
+ alignment = preq->plo->queue->limits.discard_alignment;
+ granularity = preq->plo->queue->limits.discard_granularity;
+ zeroes_data = preq->plo->queue->limits.discard_zeroes_data;
+
+ if (alignment) {
+ off_align = round_up(off, alignment);
+
+ if (zeroes_data &&
+ kaio_fill_zero_submit(file, preq,
+ off, off_align - off))
+ return -1;
+
+ size -= (off_align - off);
+ off = off_align;
+ }
+
+ if (granularity) {
+ size_t size_align;
+
+ size_align = round_down(size, granularity);
+ if (zeroes_data &&
+ kaio_fill_zero_submit(file, preq,
+ off + size_align, size - size_align))
+ return -1;
+
+ size = size_align;
+ }
+
+ *poff = off;
+ *psize = size;
+ return 0;
+}
+
/*
* WRITE case:
*
@@ -284,6 +358,11 @@ static void kaio_sbl_submit(struct file *file, struct
ploop_request *preq,
ploop_prepare_io_request(preq);
size <<= 9;
+
+ if ((rw & REQ_DISCARD) &&
+ preprocess_discard_req(file, preq, &off, &size))
+ goto out;
+
while (size > 0) {
struct kaio_req *kreq;
int nr_segs;
@@ -311,6 +390,7 @@ static void kaio_sbl_submit(struct file *file, struct
ploop_request *preq,
size -= copy;
}
+out:
kaio_complete_io_request(preq);
}
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