xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

pnfs: defer release of pages in layoutget

Browse Source 
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>
This commit is contained in:
Idan Kedar
2012-08-02 11:47:10 +03:00
committed by Trond Myklebust
parent 3dd4765fce
commit 8554116e17
3 changed files with 58 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
fs/nfs/pnfs.c
View File

@@ -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;
}
/*