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authorPeng Tao <bergwolf@gmail.com>2012-08-24 00:27:52 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-31 10:10:32 -0700
commitd1e1f0083e6cb81df51838f8a7824436edd96a95 (patch)
tree1ee57fd9f1c6b98626cdcc49f5ec3e67d4537bcd
parent2865269348c0cf5448544f971d1c64afe7cdbc98 (diff)
downloadlinux-linaro-stable-d1e1f0083e6cb81df51838f8a7824436edd96a95.tar.gz
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/nfs/blocklayout/blocklayout.c77
1 files changed, 46 insertions, 31 deletions
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index f3d16adc832c..e5dfef55f1e7 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -242,14 +242,6 @@ bl_end_par_io_read(void *data, int unused)
schedule_work(&rdata->task.u.tk_work);
}
-static bool
-bl_check_alignment(u64 offset, u32 len, unsigned long blkmask)
-{
- if ((offset & blkmask) || (len & blkmask))
- return false;
- return true;
-}
-
static enum pnfs_try_status
bl_read_pagelist(struct nfs_read_data *rdata)
{
@@ -260,15 +252,15 @@ 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);
- if (!bl_check_alignment(f_offset, rdata->args.count, PAGE_CACHE_MASK))
- goto use_mds;
-
par = alloc_parallel(rdata);
if (!par)
goto use_mds;
@@ -298,36 +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);
@@ -676,7 +685,7 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
struct bio *bio = NULL;
struct pnfs_block_extent *be = NULL, *cow_read = NULL;
sector_t isect, last_isect = 0, extent_length = 0;
- struct parallel_io *par = NULL;
+ struct parallel_io *par;
loff_t offset = wdata->args.offset;
size_t count = wdata->args.count;
unsigned int pg_offset, pg_len, saved_len;
@@ -688,10 +697,6 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
NFS_SERVER(header->inode)->pnfs_blksize >> PAGE_CACHE_SHIFT;
dprintk("%s enter, %Zu@%lld\n", __func__, count, offset);
- /* Check for alignment first */
- if (!bl_check_alignment(offset, count, PAGE_CACHE_MASK))
- goto out_mds;
-
/* At this point, wdata->pages is a (sequential) list of nfs_pages.
* We want to write each, and if there is an error set pnfs_error
* to have it redone using nfs.
@@ -1164,32 +1169,42 @@ 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 (!bl_check_alignment(req->wb_offset, req->wb_bytes, PAGE_CACHE_MASK))
+ 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 void
-bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+static bool
+bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+ struct nfs_page *req)
{
- if (!bl_check_alignment(req->wb_offset, req->wb_bytes, PAGE_CACHE_MASK))
- nfs_pageio_reset_write_mds(pgio);
- else
- pnfs_generic_pg_init_write(pgio, 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 = bl_pg_init_read,
- .pg_test = pnfs_generic_pg_test,
+ .pg_test = bl_pg_test_read,
.pg_doio = pnfs_generic_pg_readpages,
};
static const struct nfs_pageio_ops bl_pg_write_ops = {
- .pg_init = bl_pg_init_write,
+ .pg_init = pnfs_generic_pg_init_write,
.pg_test = pnfs_generic_pg_test,
.pg_doio = pnfs_generic_pg_writepages,
};