Date: Thu, 1 Aug 2019 05:30:31 +0000 (UTC) From: Doug Moore <dougm@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r350495 - stable/12/sbin/swapon Message-ID: <201908010530.x715UVEs016449@repo.freebsd.org>
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Author: dougm Date: Thu Aug 1 05:30:31 2019 New Revision: 350495 URL: https://svnweb.freebsd.org/changeset/base/350495 Log: MFC r350183, r350359 In trimming on startup, define swapon_trim() to invoke swapon before closing the fd used for trimming so that a geli device isn't detached before swapon is invoked. Add comments to explain the reason for the ordering of events. Reviewed by: alc Approved by: markj (mentor, implicit) Modified: stable/12/sbin/swapon/swapon.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sbin/swapon/swapon.c ============================================================================== --- stable/12/sbin/swapon/swapon.c Thu Aug 1 03:59:25 2019 (r350494) +++ stable/12/sbin/swapon/swapon.c Thu Aug 1 05:30:31 2019 (r350495) @@ -739,16 +739,18 @@ run_cmd(int *ofd, const char *cmdline, ...) return (WEXITSTATUS(status)); } -static void -swap_trim(const char *name) +static int +swapon_trim(const char *name) { struct stat sb; off_t ioarg[2], sz; - int fd; + int error, fd; + /* Open a descriptor to create a consumer of the device. */ fd = open(name, O_WRONLY); if (fd < 0) errx(1, "Cannot open %s", name); + /* Find the device size. */ if (fstat(fd, &sb) < 0) errx(1, "Cannot stat %s", name); if (S_ISREG(sb.st_mode)) @@ -758,11 +760,24 @@ swap_trim(const char *name) err(1, "ioctl(DIOCGMEDIASIZE)"); } else errx(1, "%s has an invalid file type", name); + /* Trim the device. */ ioarg[0] = 0; ioarg[1] = sz; if (ioctl(fd, DIOCGDELETE, ioarg) != 0) warn("ioctl(DIOCGDELETE)"); + + /* Start using the device for swapping, creating a second consumer. */ + error = swapon(name); + + /* + * Do not close the device until the swap pager has attempted to create + * another consumer. For GELI devices created with the 'detach -l' + * option, removing the last consumer causes the device to be detached + * - that is, to disappear. This ordering ensures that the device will + * not be detached until swapoff is called. + */ close(fd); + return (error); } static const char * @@ -770,11 +785,9 @@ swap_on_off_sfile(const char *name, int doingall) { int error; - if (which_prog == SWAPON) { - if (Eflag) - swap_trim(name); - error = swapon(name); - } else /* SWAPOFF */ + if (which_prog == SWAPON) + error = Eflag ? swapon_trim(name) : swapon(name); + else /* SWAPOFF */ error = swapoff(name); if (error == -1) {
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