For DIO read, if it is not sector aligned, we should reject it
and resend via MDS. Otherwise there might be data corruption.
Also teach bl_read_pagelist to handle partial page reads for DIO.
Cc: stable <stable@xxxxxxxxxxxxxxx> [since v3.4]
Signed-off-by: Peng Tao <tao.peng@xxxxxxx>
---
fs/nfs/blocklayout/blocklayout.c | 64 +++++++++++++++++++++++++++++++++-----
1 files changed, 56 insertions(+), 8 deletions(-)
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 39fa002..e5dfef5 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -252,8 +252,11 @@ bl_read_pagelist(struct nfs_read_data *rdata)
sector_t isect, extent_length = 0;
struct parallel_io *par;
loff_t f_offset = rdata->args.offset;
+ size_t bytes_left = rdata->args.count;
+ unsigned int pg_offset, pg_len;
struct page **pages = rdata->args.pages;
int pg_index = rdata->args.pgbase >> PAGE_CACHE_SHIFT;
+ const bool is_dio = (header->dreq != NULL);
dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
rdata->pages.npages, f_offset, (unsigned int)rdata->args.count);
@@ -287,36 +290,53 @@ bl_read_pagelist(struct nfs_read_data *rdata)
extent_length = min(extent_length, cow_length);
}
}
+
+ if (is_dio) {
+ pg_offset = f_offset & ~PAGE_CACHE_MASK;
+ if (pg_offset + bytes_left > PAGE_CACHE_SIZE)
+ pg_len = PAGE_CACHE_SIZE - pg_offset;
+ else
+ pg_len = bytes_left;
+
+ f_offset += pg_len;
+ bytes_left -= pg_len;
+ isect += (pg_offset >> SECTOR_SHIFT);
+ } else {
+ pg_offset = 0;
+ pg_len = PAGE_CACHE_SIZE;
+ }
+
hole = is_hole(be, isect);
if (hole && !cow_read) {
bio = bl_submit_bio(READ, bio);
/* Fill hole w/ zeroes w/o accessing device */
dprintk("%s Zeroing page for hole\n", __func__);
- zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
+ zero_user_segment(pages[i], pg_offset, pg_len);
print_page(pages[i]);
SetPageUptodate(pages[i]);
} else {
struct pnfs_block_extent *be_read;
be_read = (hole && cow_read) ? cow_read : be;
- bio = bl_add_page_to_bio(bio, rdata->pages.npages - i,
+ bio = do_add_page_to_bio(bio, rdata->pages.npages - i,
READ,
isect, pages[i], be_read,
- bl_end_io_read, par);
+ bl_end_io_read, par,
+ pg_offset, pg_len);
if (IS_ERR(bio)) {
header->pnfs_error = PTR_ERR(bio);
bio = NULL;
goto out;
}
}
- isect += PAGE_CACHE_SECTORS;
+ isect += (pg_len >> SECTOR_SHIFT);
extent_length -= PAGE_CACHE_SECTORS;
}
if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
rdata->res.eof = 1;
- rdata->res.count = header->inode->i_size - f_offset;
+ rdata->res.count = header->inode->i_size - rdata->args.offset;
} else {
- rdata->res.count = (isect << SECTOR_SHIFT) - f_offset;
+ rdata->res.count = (isect << SECTOR_SHIFT) - rdata->args.offset;
}
out:
bl_put_extent(be);
@@ -1149,9 +1169,37 @@ bl_clear_layoutdriver(struct nfs_server *server)
return 0;
}
+static bool
+is_aligned_req(struct nfs_page *req, unsigned int alignment)
+{
+ return IS_ALIGNED(req->wb_offset, alignment) &&
+ IS_ALIGNED(req->wb_bytes, alignment);
+}
+
+static void
+bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+ if (pgio->pg_dreq != NULL &&
+ !is_aligned_req(req, SECTOR_SIZE))
+ nfs_pageio_reset_read_mds(pgio);
+ else
+ pnfs_generic_pg_init_read(pgio, req);
+}
+
+static bool
+bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+ struct nfs_page *req)
+{
+ if (pgio->pg_dreq != NULL &&
+ !is_aligned_req(req, SECTOR_SIZE))
+ return false;
+
+ return pnfs_generic_pg_test(pgio, prev, req);
+}
+
static const struct nfs_pageio_ops bl_pg_read_ops = {
- .pg_init = pnfs_generic_pg_init_read,
- .pg_test = pnfs_generic_pg_test,
+ .pg_init = bl_pg_init_read,
+ .pg_test = bl_pg_test_read,
.pg_doio = pnfs_generic_pg_readpages,
};
--
1.7.1.262.g5ef3d
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