[PATCH] NFS: large non-page-aligned direct I/O clobbers memory
The logic in nfs_direct_read_schedule and nfs_direct_write_schedule can
allow data->npages to be one larger than rpages. This causes a page
pointer to be written beyond the end of the pagevec in nfs_read_data (or
nfs_write_data).
Fix this by making nfs_(read|write)_alloc() calculate the size of the
pagevec array, and initialise data->npages.
Also get rid of the redundant argument to nfs_commit_alloc().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 2474345..530b1e6 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -427,7 +427,7 @@
extern void nfs_writedata_release(void *);
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-struct nfs_write_data *nfs_commit_alloc(unsigned int pagecount);
+struct nfs_write_data *nfs_commit_alloc(void);
void nfs_commit_free(struct nfs_write_data *p);
#endif
@@ -478,7 +478,7 @@
/*
* Allocate nfs_write_data structures
*/
-extern struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount);
+extern struct nfs_write_data *nfs_writedata_alloc(size_t len);
/*
* linux/fs/nfs/read.c
@@ -492,7 +492,7 @@
/*
* Allocate nfs_read_data structures
*/
-extern struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount);
+extern struct nfs_read_data *nfs_readdata_alloc(size_t len);
/*
* linux/fs/nfs3proc.c
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index db9cbf6..41e5a19 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -729,7 +729,7 @@
struct list_head pages; /* Coalesced read requests */
struct nfs_page *req; /* multi ops per nfs_page */
struct page **pagevec;
- unsigned int npages; /* active pages in pagevec */
+ unsigned int npages; /* Max length of pagevec */
struct nfs_readargs args;
struct nfs_readres res;
#ifdef CONFIG_NFS_V4
@@ -748,7 +748,7 @@
struct list_head pages; /* Coalesced requests we wish to flush */
struct nfs_page *req; /* multi ops per nfs_page */
struct page **pagevec;
- unsigned int npages; /* active pages in pagevec */
+ unsigned int npages; /* Max length of pagevec */
struct nfs_writeargs args; /* argument struct */
struct nfs_writeres res; /* result struct */
#ifdef CONFIG_NFS_V4