Date: Sun, 14 Feb 2016 19:52:50 +0000 (UTC) From: "Pedro F. Giffuni" <pfg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r295616 - head/sys/fs/ext2fs Message-ID: <201602141952.u1EJqoN1072954@repo.freebsd.org>
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Author: pfg Date: Sun Feb 14 19:52:50 2016 New Revision: 295616 URL: https://svnweb.freebsd.org/changeset/base/295616 Log: ext2fs: Remove panics for rename() race conditions. Sync with r84642 from UFS: The panics are inappropriate because the IN_RENAME flag only fixes a few of the huge number of race conditions that can result in the source path becoming invalid even prior to the VOP_RENAME() call. Found accidentally while checking an issue from PVS Static Analysis. MFC after: 3 days Modified: head/sys/fs/ext2fs/ext2_vnops.c Modified: head/sys/fs/ext2fs/ext2_vnops.c ============================================================================== --- head/sys/fs/ext2fs/ext2_vnops.c Sun Feb 14 18:57:40 2016 (r295615) +++ head/sys/fs/ext2fs/ext2_vnops.c Sun Feb 14 19:52:50 2016 (r295616) @@ -985,10 +985,10 @@ abortit: dp = VTOI(fdvp); } else { /* - * From name has disappeared. + * From name has disappeared. IN_RENAME is not sufficient + * to protect against directory races due to timing windows, + * so we can't panic here. */ - if (doingdirectory) - panic("ext2_rename: lost dir entry"); vrele(ap->a_fvp); return (0); } @@ -1003,8 +1003,11 @@ abortit: * rename. */ if (xp != ip) { - if (doingdirectory) - panic("ext2_rename: lost dir entry"); + /* + * From name resolves to a different inode. IN_RENAME is + * not sufficient protection against timing window races + * so we can't panic here. + */ } else { /* * If the source is a directory with a
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