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authorNeil Brown <neilb@suse.de>2012-12-07 15:40:55 -0500
committerJ. Bruce Fields <bfields@redhat.com>2012-12-10 16:25:31 -0500
commit7007c90fb9fef593b4aeaeee57e6a6754276c97c (patch)
tree8fe1b5daa2132876b364801aaef4127774c6c4b3 /fs
parent756933ee8a75970ca7d8a10e922f5d44720457a4 (diff)
nfsd: avoid permission checks on EXCLUSIVE_CREATE replay
With NFSv4, if we create a file then open it we explicit avoid checking the permissions on the file during the open because the fact that we created it ensures we should be allow to open it (the create and the open should appear to be a single operation). However if the reply to an EXCLUSIVE create gets lots and the client resends the create, the current code will perform the permission check - because it doesn't realise that it did the open already.. This patch should fix this. Note that I haven't actually seen this cause a problem. I was just looking at the code trying to figure out a different EXCLUSIVE open related issue, and this looked wrong. (Fix confirmed with pynfs 4.0 test OPEN4--bfields) Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de> [bfields: use OWNER_OVERRIDE and update for 4.1] Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/nfs4proc.c8
-rw-r--r--fs/nfsd/vfs.c10
2 files changed, 13 insertions, 5 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 87d24e5f3ca..1a0b1fdb5ad 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -195,6 +195,7 @@ static __be32
195do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open) 195do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
196{ 196{
197 struct svc_fh *resfh; 197 struct svc_fh *resfh;
198 int accmode;
198 __be32 status; 199 __be32 status;
199 200
200 resfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL); 201 resfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
@@ -254,9 +255,10 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
254 /* set reply cache */ 255 /* set reply cache */
255 fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh, 256 fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
256 &resfh->fh_handle); 257 &resfh->fh_handle);
257 if (!open->op_created) 258 accmode = NFSD_MAY_NOP;
258 status = do_open_permission(rqstp, resfh, open, 259 if (open->op_created)
259 NFSD_MAY_NOP); 260 accmode |= NFSD_MAY_OWNER_OVERRIDE;
261 status = do_open_permission(rqstp, resfh, open, accmode);
260 set_change_info(&open->op_cinfo, current_fh); 262 set_change_info(&open->op_cinfo, current_fh);
261 fh_dup2(current_fh, resfh); 263 fh_dup2(current_fh, resfh);
262out: 264out:
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index b584205b25b..0ef9b6b410a 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1471,13 +1471,19 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1471 case NFS3_CREATE_EXCLUSIVE: 1471 case NFS3_CREATE_EXCLUSIVE:
1472 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1472 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1473 && dchild->d_inode->i_atime.tv_sec == v_atime 1473 && dchild->d_inode->i_atime.tv_sec == v_atime
1474 && dchild->d_inode->i_size == 0 ) 1474 && dchild->d_inode->i_size == 0 ) {
1475 if (created)
1476 *created = 1;
1475 break; 1477 break;
1478 }
1476 case NFS4_CREATE_EXCLUSIVE4_1: 1479 case NFS4_CREATE_EXCLUSIVE4_1:
1477 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1480 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1478 && dchild->d_inode->i_atime.tv_sec == v_atime 1481 && dchild->d_inode->i_atime.tv_sec == v_atime
1479 && dchild->d_inode->i_size == 0 ) 1482 && dchild->d_inode->i_size == 0 ) {
1483 if (created)
1484 *created = 1;
1480 goto set_attr; 1485 goto set_attr;
1486 }
1481 /* fallthru */ 1487 /* fallthru */
1482 case NFS3_CREATE_GUARDED: 1488 case NFS3_CREATE_GUARDED:
1483 err = nfserr_exist; 1489 err = nfserr_exist;