@@ -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,
};
This is a note to let you know that I have just added a patch titled pnfsblock: fix non-aligned DIO read to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.yuz tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From 9e2e377791043dc36dc22fb9341c2e4ff031ca52 Mon Sep 17 00:00:00 2001 From: Peng Tao <bergwolf@gmail.com> Date: Fri, 24 Aug 2012 00:27:52 +0800 Subject: [PATCH] pnfsblock: fix non-aligned DIO read commit f742dc4a32587bff50b13dde9d8894b96851951a upstream. 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. Signed-off-by: Peng Tao <tao.peng@emc.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- fs/nfs/blocklayout/blocklayout.c | 64 +++++++++++++++++++++++++++++++++----- 1 file changed, 56 insertions(+), 8 deletions(-) -- 1.7.9.5