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authorIdan Kedar <idank@tonian.com>2012-08-02 11:47:10 +0300
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-08-02 17:38:54 -0400
commit8554116e17eef055d9dd58a94b3427cb2ad1c317 (patch)
tree75cb529c3ab86a496536a285542d79d064284d48 /fs/nfs
parent3dd4765fce04c0b4af1e0bc4c0b10f906f95fabc (diff)
downloadop-kernel-dev-8554116e17eef055d9dd58a94b3427cb2ad1c317.zip
op-kernel-dev-8554116e17eef055d9dd58a94b3427cb2ad1c317.tar.gz
pnfs: defer release of pages in layoutget
we have encountered a bug whereby reading a lot of files (copying fedora's /bin) from a pNFS mount and hitting Ctrl+C in the middle caused a general protection fault in xdr_shrink_bufhead. this function is called when decoding the response from LAYOUTGET. the decoding is done by a worker thread, and the caller of LAYOUTGET waits for the worker thread to complete. hitting Ctrl+C caused the synchronous wait to end and the next thing the caller does is to free the pages, so when the worker thread calls xdr_shrink_bufhead, the pages are gone. therefore, the cleanup of these pages has been moved to nfs4_layoutget_release. Signed-off-by: Idan Kedar <idank@tonian.com> Signed-off-by: Benny Halevy <bhalevy@tonian.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4proc.c57
-rw-r--r--fs/nfs/pnfs.c39
-rw-r--r--fs/nfs/pnfs.h2
3 files changed, 58 insertions, 40 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index a99a8d9..6a78d49 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6223,11 +6223,58 @@ static void nfs4_layoutget_done(struct rpc_task *task, void *calldata)
dprintk("<-- %s\n", __func__);
}
+static size_t max_response_pages(struct nfs_server *server)
+{
+ u32 max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
+ return nfs_page_array_len(0, max_resp_sz);
+}
+
+static void nfs4_free_pages(struct page **pages, size_t size)
+{
+ int i;
+
+ if (!pages)
+ return;
+
+ for (i = 0; i < size; i++) {
+ if (!pages[i])
+ break;
+ __free_page(pages[i]);
+ }
+ kfree(pages);
+}
+
+static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
+{
+ struct page **pages;
+ int i;
+
+ pages = kcalloc(size, sizeof(struct page *), gfp_flags);
+ if (!pages) {
+ dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
+ return NULL;
+ }
+
+ for (i = 0; i < size; i++) {
+ pages[i] = alloc_page(gfp_flags);
+ if (!pages[i]) {
+ dprintk("%s: failed to allocate page\n", __func__);
+ nfs4_free_pages(pages, size);
+ return NULL;
+ }
+ }
+
+ return pages;
+}
+
static void nfs4_layoutget_release(void *calldata)
{
struct nfs4_layoutget *lgp = calldata;
+ struct nfs_server *server = NFS_SERVER(lgp->args.inode);
+ size_t max_pages = max_response_pages(server);
dprintk("--> %s\n", __func__);
+ nfs4_free_pages(lgp->args.layout.pages, max_pages);
put_nfs_open_context(lgp->args.ctx);
kfree(calldata);
dprintk("<-- %s\n", __func__);
@@ -6239,9 +6286,10 @@ static const struct rpc_call_ops nfs4_layoutget_call_ops = {
.rpc_release = nfs4_layoutget_release,
};
-int nfs4_proc_layoutget(struct nfs4_layoutget *lgp)
+int nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags)
{
struct nfs_server *server = NFS_SERVER(lgp->args.inode);
+ size_t max_pages = max_response_pages(server);
struct rpc_task *task;
struct rpc_message msg = {
.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTGET],
@@ -6259,6 +6307,13 @@ int nfs4_proc_layoutget(struct nfs4_layoutget *lgp)
dprintk("--> %s\n", __func__);
+ lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
+ if (!lgp->args.layout.pages) {
+ nfs4_layoutget_release(lgp);
+ return -ENOMEM;
+ }
+ lgp->args.layout.pglen = max_pages * PAGE_SIZE;
+
lgp->res.layoutp = &lgp->args.layout;
lgp->res.seq_res.sr_slot = NULL;
nfs41_init_sequence(&lgp->args.seq_args, &lgp->res.seq_res, 0);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 76875bf..2e00fea 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -583,9 +583,6 @@ send_layoutget(struct pnfs_layout_hdr *lo,
struct nfs_server *server = NFS_SERVER(ino);
struct nfs4_layoutget *lgp;
struct pnfs_layout_segment *lseg = NULL;
- struct page **pages = NULL;
- int i;
- u32 max_resp_sz, max_pages;
dprintk("--> %s\n", __func__);
@@ -594,20 +591,6 @@ send_layoutget(struct pnfs_layout_hdr *lo,
if (lgp == NULL)
return NULL;
- /* allocate pages for xdr post processing */
- max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
- max_pages = nfs_page_array_len(0, max_resp_sz);
-
- pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
- if (!pages)
- goto out_err_free;
-
- for (i = 0; i < max_pages; i++) {
- pages[i] = alloc_page(gfp_flags);
- if (!pages[i])
- goto out_err_free;
- }
-
lgp->args.minlength = PAGE_CACHE_SIZE;
if (lgp->args.minlength > range->length)
lgp->args.minlength = range->length;
@@ -616,39 +599,19 @@ send_layoutget(struct pnfs_layout_hdr *lo,
lgp->args.type = server->pnfs_curr_ld->id;
lgp->args.inode = ino;
lgp->args.ctx = get_nfs_open_context(ctx);
- lgp->args.layout.pages = pages;
- lgp->args.layout.pglen = max_pages * PAGE_SIZE;
lgp->lsegpp = &lseg;
lgp->gfp_flags = gfp_flags;
/* Synchronously retrieve layout information from server and
* store in lseg.
*/
- nfs4_proc_layoutget(lgp);
+ nfs4_proc_layoutget(lgp, gfp_flags);
if (!lseg) {
/* remember that LAYOUTGET failed and suspend trying */
set_bit(lo_fail_bit(range->iomode), &lo->plh_flags);
}
- /* free xdr pages */
- for (i = 0; i < max_pages; i++)
- __free_page(pages[i]);
- kfree(pages);
-
return lseg;
-
-out_err_free:
- /* free any allocated xdr pages, lgp as it's not used */
- if (pages) {
- for (i = 0; i < max_pages; i++) {
- if (!pages[i])
- break;
- __free_page(pages[i]);
- }
- kfree(pages);
- }
- kfree(lgp);
- return NULL;
}
/*
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 2c6c805..5ea019e 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -172,7 +172,7 @@ extern int nfs4_proc_getdevicelist(struct nfs_server *server,
struct pnfs_devicelist *devlist);
extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
struct pnfs_device *dev);
-extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
+extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags);
extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
/* pnfs.c */
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