From ae46141ff08f1965b17c531b571953c39ce8b9e2 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 10 Mar 2009 20:33:18 -0400 Subject: [PATCH] NFSv3: Fix posix ACL code Fix a memory leak due to allocation in the XDR layer. In cases where the RPC call needs to be retransmitted, we end up allocating new pages without clearing the old ones. Fix this by moving the allocation into nfs3_proc_setacls(). Also fix an issue discovered by Kevin Rudd, whereby the amount of memory reserved for the acls in the xdr_buf->head was miscalculated, and causing corruption. Signed-off-by: Trond Myklebust --- fs/nfs/nfs3acl.c | 27 +++++++++++++++++++++------ fs/nfs/nfs3xdr.c | 32 ++++++++++++-------------------- include/linux/nfs_xdr.h | 2 ++ include/linux/nfsacl.h | 3 +++ 4 files changed, 38 insertions(+), 26 deletions(-) diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c index cef62557c87d..6bbf0e6daad2 100644 --- a/fs/nfs/nfs3acl.c +++ b/fs/nfs/nfs3acl.c @@ -292,7 +292,7 @@ static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl, { struct nfs_server *server = NFS_SERVER(inode); struct nfs_fattr fattr; - struct page *pages[NFSACL_MAXPAGES] = { }; + struct page *pages[NFSACL_MAXPAGES]; struct nfs3_setaclargs args = { .inode = inode, .mask = NFS_ACL, @@ -303,7 +303,7 @@ static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl, .rpc_argp = &args, .rpc_resp = &fattr, }; - int status, count; + int status; status = -EOPNOTSUPP; if (!nfs_server_capable(inode, NFS_CAP_ACLS)) @@ -319,6 +319,20 @@ static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl, if (S_ISDIR(inode->i_mode)) { args.mask |= NFS_DFACL; args.acl_default = dfacl; + args.len = nfsacl_size(acl, dfacl); + } else + args.len = nfsacl_size(acl, NULL); + + if (args.len > NFS_ACL_INLINE_BUFSIZE) { + unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT); + + status = -ENOMEM; + do { + args.pages[args.npages] = alloc_page(GFP_KERNEL); + if (args.pages[args.npages] == NULL) + goto out_freepages; + args.npages++; + } while (args.npages < npages); } dprintk("NFS call setacl\n"); @@ -329,10 +343,6 @@ static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl, nfs_zap_acl_cache(inode); dprintk("NFS reply setacl: %d\n", status); - /* pages may have been allocated at the xdr layer. */ - for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++) - __free_page(args.pages[count]); - switch (status) { case 0: status = nfs_refresh_inode(inode, &fattr); @@ -346,6 +356,11 @@ static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl, case -ENOTSUPP: status = -EOPNOTSUPP; } +out_freepages: + while (args.npages != 0) { + args.npages--; + __free_page(args.pages[args.npages]); + } out: return status; } diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c index 11cdddec1432..6cdeacffde46 100644 --- a/fs/nfs/nfs3xdr.c +++ b/fs/nfs/nfs3xdr.c @@ -82,8 +82,10 @@ #define NFS3_commitres_sz (1+NFS3_wcc_data_sz+2) #define ACL3_getaclargs_sz (NFS3_fh_sz+1) -#define ACL3_setaclargs_sz (NFS3_fh_sz+1+2*(2+5*3)) -#define ACL3_getaclres_sz (1+NFS3_post_op_attr_sz+1+2*(2+5*3)) +#define ACL3_setaclargs_sz (NFS3_fh_sz+1+ \ + XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)) +#define ACL3_getaclres_sz (1+NFS3_post_op_attr_sz+1+ \ + XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)) #define ACL3_setaclres_sz (1+NFS3_post_op_attr_sz) /* @@ -703,28 +705,18 @@ nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p, struct nfs3_setaclargs *args) { struct xdr_buf *buf = &req->rq_snd_buf; - unsigned int base, len_in_head, len = nfsacl_size( - (args->mask & NFS_ACL) ? args->acl_access : NULL, - (args->mask & NFS_DFACL) ? args->acl_default : NULL); - int count, err; + unsigned int base; + int err; p = xdr_encode_fhandle(p, NFS_FH(args->inode)); *p++ = htonl(args->mask); - base = (char *)p - (char *)buf->head->iov_base; - /* put as much of the acls into head as possible. */ - len_in_head = min_t(unsigned int, buf->head->iov_len - base, len); - len -= len_in_head; - req->rq_slen = xdr_adjust_iovec(req->rq_svec, p + (len_in_head >> 2)); + req->rq_slen = xdr_adjust_iovec(req->rq_svec, p); + base = req->rq_slen; - for (count = 0; (count << PAGE_SHIFT) < len; count++) { - args->pages[count] = alloc_page(GFP_KERNEL); - if (!args->pages[count]) { - while (count) - __free_page(args->pages[--count]); - return -ENOMEM; - } - } - xdr_encode_pages(buf, args->pages, 0, len); + if (args->npages != 0) + xdr_encode_pages(buf, args->pages, 0, args->len); + else + req->rq_slen += args->len; err = nfsacl_encode(buf, base, args->inode, (args->mask & NFS_ACL) ? diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index a550b528319f..2e5f00066afd 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -406,6 +406,8 @@ struct nfs3_setaclargs { int mask; struct posix_acl * acl_access; struct posix_acl * acl_default; + size_t len; + unsigned int npages; struct page ** pages; }; diff --git a/include/linux/nfsacl.h b/include/linux/nfsacl.h index 54487a99beb8..43011b69297c 100644 --- a/include/linux/nfsacl.h +++ b/include/linux/nfsacl.h @@ -37,6 +37,9 @@ #define NFSACL_MAXPAGES ((2*(8+12*NFS_ACL_MAX_ENTRIES) + PAGE_SIZE-1) \ >> PAGE_SHIFT) +#define NFS_ACL_MAX_ENTRIES_INLINE (5) +#define NFS_ACL_INLINE_BUFSIZE ((2*(2+3*NFS_ACL_MAX_ENTRIES_INLINE)) << 2) + static inline unsigned int nfsacl_size(struct posix_acl *acl_access, struct posix_acl *acl_default) {