Date: Sat, 28 Jun 2014 21:47:16 +0000 (UTC) From: Rick Macklem <rmacklem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r268008 - head/sys/fs/nfsclient Message-ID: <201406282147.s5SLlGQH094279@svn.freebsd.org>
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Author: rmacklem Date: Sat Jun 28 21:47:15 2014 New Revision: 268008 URL: http://svnweb.freebsd.org/changeset/base/268008 Log: There might be a potential race condition for the NFSv4 client when a newly created file has another open done on it that update the open mode. This patch moves the code that updates the open mode up into the block where the mutex is held to ensure this cannot happen. No bug caused by this potential race has been observed, but this fix is a safety belt to ensure it cannot happen. MFC after: 2 weeks Modified: head/sys/fs/nfsclient/nfs_clstate.c Modified: head/sys/fs/nfsclient/nfs_clstate.c ============================================================================== --- head/sys/fs/nfsclient/nfs_clstate.c Sat Jun 28 19:59:12 2014 (r268007) +++ head/sys/fs/nfsclient/nfs_clstate.c Sat Jun 28 21:47:15 2014 (r268008) @@ -281,6 +281,23 @@ nfscl_open(vnode_t vp, u_int8_t *nfhp, i newonep); /* + * Now, check the mode on the open and return the appropriate + * value. + */ + if (retp != NULL) { + if (nfhp != NULL && dp != NULL && nop == NULL) + /* new local open on delegation */ + *retp = NFSCLOPEN_SETCRED; + else + *retp = NFSCLOPEN_OK; + } + if (op != NULL && (amode & ~(op->nfso_mode))) { + op->nfso_mode |= amode; + if (retp != NULL && dp == NULL) + *retp = NFSCLOPEN_DOOPEN; + } + + /* * Serialize modifications to the open owner for multiple threads * within the same process using a read/write sleep lock. */ @@ -295,23 +312,6 @@ nfscl_open(vnode_t vp, u_int8_t *nfhp, i *owpp = owp; if (opp != NULL) *opp = op; - if (retp != NULL) { - if (nfhp != NULL && dp != NULL && nop == NULL) - /* new local open on delegation */ - *retp = NFSCLOPEN_SETCRED; - else - *retp = NFSCLOPEN_OK; - } - - /* - * Now, check the mode on the open and return the appropriate - * value. - */ - if (op != NULL && (amode & ~(op->nfso_mode))) { - op->nfso_mode |= amode; - if (retp != NULL && dp == NULL) - *retp = NFSCLOPEN_DOOPEN; - } return (0); }
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