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pnfsblock: bail out partial page IO

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Current block layout driver read/write code assumes page
aligned IO in many places. Add a checker to validate the assumption.
Otherwise there would be data corruption like when application does
open(O_WRONLY) and page unaliged write.

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Peng Tao 2012-05-29 13:57:58 +08:00 committed by Trond Myklebust
parent f44106e217
commit 159e0561e3
1 changed files with 36 additions and 3 deletions
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39
fs/nfs/blocklayout/blocklayout.c
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@ -228,6 +228,14 @@ 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)
{
@ -244,6 +252,9 @@ bl_read_pagelist(struct nfs_read_data *rdata)
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;
@ -552,7 +563,7 @@ 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;
struct parallel_io *par = NULL;
loff_t offset = wdata->args.offset;
size_t count = wdata->args.count;
struct page **pages = wdata->args.pages;
@ -563,6 +574,10 @@ 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.
@ -996,14 +1011,32 @@ bl_clear_layoutdriver(struct nfs_server *server)
return 0;
}
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))
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)
{
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);
}
static const struct nfs_pageio_ops bl_pg_read_ops = {
.pg_init = pnfs_generic_pg_init_read,
.pg_init = bl_pg_init_read,
.pg_test = pnfs_generic_pg_test,
.pg_doio = pnfs_generic_pg_readpages,
};
static const struct nfs_pageio_ops bl_pg_write_ops = {
.pg_init = pnfs_generic_pg_init_write,
.pg_init = bl_pg_init_write,
.pg_test = pnfs_generic_pg_test,
.pg_doio = pnfs_generic_pg_writepages,
};