[PATCH] kNFSd: Enforce open_downgrade requirement

From: NeilBrown <neilb@cse.unsw.edu.au>

The spec requires that the access and deny bits requested in open_downgrade
represent the union of the bits for some subset of the OPENS for the given
open_owner and file.  Enforce that requirement.

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 859ac37364d2752ba072556308ef82e6bc9055a5..5d1f0009ee4ca69945723873e0431a7479d75948 100644 (file)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -381,6 +381,20 @@ nfsd4_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_loo
        return nfsd_lookup(rqstp, current_fh, lookup->lo_name, lookup->lo_len, current_fh);
 }
 
+static inline int
+access_bits_permit_read(unsigned long access_bmap)
+{
+       return test_bit(NFS4_SHARE_ACCESS_READ, &access_bmap) ||
+               test_bit(NFS4_SHARE_ACCESS_BOTH, &access_bmap);
+}
+
+static inline int
+access_bits_permit_write(unsigned long access_bmap)
+{
+       return test_bit(NFS4_SHARE_ACCESS_WRITE, &access_bmap) ||
+               test_bit(NFS4_SHARE_ACCESS_BOTH, &access_bmap);
+}
+
 static inline int
 nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read *read)
 {
@@ -419,7 +433,7 @@ nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read
                goto out;
        }
        status = nfserr_openmode;
-       if (!(stp->st_share_access & NFS4_SHARE_ACCESS_READ)) {
+       if (!access_bits_permit_read(stp->st_access_bmap)) {
                dprintk("NFSD: nfsd4_read: file not opened for read!\n");
                goto out;
        }
@@ -527,7 +541,7 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_se
                        goto out;
                }
                status = nfserr_openmode;
-               if (!(stp->st_share_access & NFS4_SHARE_ACCESS_WRITE)) {
+               if (!access_bits_permit_write(stp->st_access_bmap)) {
                        dprintk("NFSD: nfsd4_setattr: not opened for write!\n");
                        goto out;
                }
@@ -568,7 +582,7 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
        }
 
        status = nfserr_openmode;
-       if (!(stp->st_share_access & NFS4_SHARE_ACCESS_WRITE)) {
+       if (!access_bits_permit_write(stp->st_access_bmap)) {
                dprintk("NFSD: nfsd4_write: file not open for write!\n");
                goto out;
        }

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0e7e5a06d1f04f77ffe8954f42efc8798643b93d..13ca74de2a21aad0a677705c2c059491de80ea7d 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -844,8 +844,10 @@ init_stateid(struct nfs4_stateid *stp, struct nfs4_file *fp, struct nfs4_stateow
        stp->st_stateid.si_stateownerid = sop->so_id;
        stp->st_stateid.si_fileid = fp->fi_id;
        stp->st_stateid.si_generation = 0;
-       stp->st_share_access = open->op_share_access;
-       stp->st_share_deny = open->op_share_deny;
+       stp->st_access_bmap = 0;
+       stp->st_deny_bmap = 0;
+       __set_bit(open->op_share_access, &stp->st_access_bmap);
+       __set_bit(open->op_share_deny, &stp->st_deny_bmap);
 }
 
 static void
@@ -962,15 +964,46 @@ find_file(unsigned int hashval, struct inode *ino, struct nfs4_file **fp) {
        return 0;
 }
 
+#define TEST_ACCESS(x) ((x > 0 || x < 4)?1:0)
+#define TEST_DENY(x) ((x >= 0 || x < 5)?1:0)
+
+void
+set_access(unsigned int *access, unsigned long bmap) {
+       int i;
+
+       *access = 0;
+       for (i = 1; i < 4; i++) {
+               if(test_bit(i, &bmap))
+                       *access |= i;
+       }
+}
+
+void
+set_deny(unsigned int *deny, unsigned long bmap) {
+       int i;
+
+       *deny = 0;
+       for (i = 0; i < 4; i++) {
+               if(test_bit(i, &bmap))
+                       *deny |= i ;
+       }
+}
+
 static int
 test_share(struct nfs4_stateid *stp, struct nfsd4_open *open) {
-       if ((stp->st_share_access & open->op_share_deny) ||
-           (stp->st_share_deny & open->op_share_access)) {
+       unsigned int access, deny;
+
+       set_access(&access, stp->st_access_bmap);
+       set_deny(&deny, stp->st_deny_bmap);
+       if ((access & open->op_share_deny) || (deny & open->op_share_access))
                return 0;
-       }
        return 1;
 }
 
+/*
+ * Called to check deny when READ with all zero stateid or
+ * WRITE with all zero or all one stateid
+ */
 int
 nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
 {
@@ -987,7 +1020,8 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
        /* Search for conflicting share reservations */
                list_for_each_safe(pos, next, &fp->fi_perfile) {
                        stp = list_entry(pos, struct nfs4_stateid, st_perfile);
-                       if (stp->st_share_deny & deny_type)
+                       if (test_bit(deny_type, &stp->st_deny_bmap) ||
+                           test_bit(NFS4_SHARE_DENY_BOTH, &stp->st_deny_bmap))
                                return nfserr_share_denied;
                }
        }
@@ -1130,6 +1164,10 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
 
        ino = current_fh->fh_dentry->d_inode;
 
+       status = nfserr_inval;
+       if (!TEST_ACCESS(open->op_share_access) || !TEST_DENY(open->op_share_deny))
+               goto out;
+
        nfs4_lock_state();
        fi_hashval = file_hashval(ino);
        if (find_file(fi_hashval, ino, &fp)) {
@@ -1181,15 +1219,18 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
                /* This is an upgrade of an existing OPEN. 
                 * OR the incoming share with the existing 
                 * nfs4_stateid share */
-               int share_access = open->op_share_access;
+               unsigned int share_access;
 
-               share_access &= ~(stp->st_share_access);
+               set_access(&share_access, stp->st_access_bmap);
+               share_access = ~share_access;
+               share_access &= open->op_share_access;
 
                /* update the struct file */
                if ((status = nfs4_file_upgrade(&stp->st_vfs_file, share_access)))
                        goto out;
-               stp->st_share_access |= share_access;
-               stp->st_share_deny |= open->op_share_deny;
+               /* remember the open */
+               set_bit(open->op_share_access, &stp->st_access_bmap);
+               set_bit(open->op_share_deny, &stp->st_deny_bmap);
                /* bump the stateid */
                update_stateid(&stp->st_stateid);
        }
@@ -1517,10 +1558,11 @@ check_replay:
                printk("NFSD: preprocess_seqid_op: retransmission?\n");
                /* indicate replay to calling function */
                status = NFSERR_REPLAY_ME;
-       } else 
+       } else  {
                printk("NFSD: preprocess_seqid_op: bad seqid (expected %d, got %d\n", sop->so_seqid +1, seqid);
 
                status = nfserr_bad_seqid;
+       }
        goto out;
 }
 
@@ -1562,16 +1604,48 @@ out:
        nfs4_unlock_state();
        return status;
 }
+
+
+/*
+ * unset all bits in union bitmap (bmap) that
+ * do not exist in share (from successful OPEN_DOWNGRADE)
+ */
+static void
+reset_union_bmap_access(unsigned long access, unsigned long *bmap)
+{
+       int i;
+       for (i = 1; i < 4; i++) {
+               if ((i & access) != i)
+                       __clear_bit(i, bmap);
+       }
+}
+
+static void
+reset_union_bmap_deny(unsigned long deny, unsigned long *bmap)
+{
+       int i;
+       for (i = 0; i < 4; i++) {
+               if ((i & deny) != i)
+                       __clear_bit(i, bmap);
+       }
+}
+
+
 int
 nfsd4_open_downgrade(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open_downgrade *od)
 {
        int status;
        struct nfs4_stateid *stp;
+       unsigned int share_access;
 
        dprintk("NFSD: nfsd4_open_downgrade on file %.*s\n", 
                        (int)current_fh->fh_dentry->d_name.len,
                        current_fh->fh_dentry->d_name.name);
 
+       status = nfserr_inval;
+       if (!TEST_ACCESS(od->od_share_access) || !TEST_DENY(od->od_share_deny))
+               goto out;
+
        nfs4_lock_state();
        if ((status = nfs4_preprocess_seqid_op(current_fh, od->od_seqid, 
                                        &od->od_stateid, 
@@ -1580,20 +1654,23 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct n
                goto out; 
 
        status = nfserr_inval;
-       if (od->od_share_access & ~stp->st_share_access) {
-               dprintk("NFSD:access not a subset current=%08x, desired=%08x\n", 
-                       stp->st_share_access, od->od_share_access); 
+       if (!test_bit(od->od_share_access, &stp->st_access_bmap)) {
+               dprintk("NFSD:access not a subset current bitmap: 0x%lx, input access=%08x\n",
+                       stp->st_access_bmap, od->od_share_access);
                goto out;
        }
-       if (od->od_share_deny & ~stp->st_share_deny) {
-               dprintk("NFSD:deny not a subset current=%08x, desired=%08x\n", 
-                       stp->st_share_deny, od->od_share_deny);
+       if (!test_bit(od->od_share_deny, &stp->st_deny_bmap)) {
+               dprintk("NFSD:deny not a subset current bitmap: 0x%lx, input deny=%08x\n",
+                       stp->st_deny_bmap, od->od_share_deny);
                goto out;
        }
+       set_access(&share_access, stp->st_access_bmap);
        nfs4_file_downgrade(&stp->st_vfs_file, 
-       stp->st_share_access & ~od->od_share_access);
-       stp->st_share_access = od->od_share_access;
-       stp->st_share_deny = od->od_share_deny;
+                           share_access & ~od->od_share_access);
+
+       reset_union_bmap_access(od->od_share_access, &stp->st_access_bmap);
+       reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap);
+
        update_stateid(&stp->st_stateid);
        memcpy(&od->od_stateid, &stp->st_stateid, sizeof(stateid_t));
        status = nfs_ok;
@@ -1820,8 +1897,8 @@ alloc_init_lock_stateid(struct nfs4_stateowner *sop, struct nfs4_file *fp, struc
        stp->st_stateid.si_generation = 0;
        stp->st_vfs_file = open_stp->st_vfs_file;
        stp->st_vfs_set = open_stp->st_vfs_set;
-       stp->st_share_access = -1; 
-       stp->st_share_deny = -1;
+       stp->st_access_bmap = open_stp->st_access_bmap;
+       stp->st_deny_bmap = open_stp->st_deny_bmap;
 
 out:
        return stp;

diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 72c2a08c09ed2836ea7ff0cd69f8335fa5d778b0..e8ea2239a213e6090bb7f7ae04346cc4e063ef99 100644 (file)
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -37,6 +37,7 @@
 #define NFS4_SHARE_ACCESS_BOTH 0x0003
 #define NFS4_SHARE_DENY_READ   0x0001
 #define NFS4_SHARE_DENY_WRITE  0x0002
+#define NFS4_SHARE_DENY_BOTH   0x0003
 
 #define NFS4_SET_TO_SERVER_TIME        0
 #define NFS4_SET_TO_CLIENT_TIME        1

diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 27febf82dfca3598ca2adf86b3fe6c97536e59fe..4598b975666886d49a43b34347aeb240ae8d84e0 100644 (file)
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -170,8 +170,8 @@ struct nfs4_file {
 *      st_perfile: file_hashtbl[] entry.
 *      st_perfile_state: nfs4_stateowner->so_perfilestate
 *       st_perlockowner: (open stateid) list of lock nfs4_stateowners
-*      st_share_access: used only for open stateid
-*      st_share_deny: used only for open stateid
+*      st_access_bmap: used only for open stateid
+*      st_deny_bmap: used only for open stateid
 */
 
 struct nfs4_stateid {
@@ -184,8 +184,8 @@ struct nfs4_stateid {
        stateid_t                     st_stateid;
        struct file                   st_vfs_file;
        int                           st_vfs_set;
-       unsigned int                  st_share_access;
-       unsigned int                  st_share_deny;
+       unsigned long                 st_access_bmap;
+       unsigned long                 st_deny_bmap;
 };
 
 /* flags for preprocess_seqid_op() */