Date: Wed, 10 Apr 2013 22:12:22 +0000 (UTC) From: "Kenneth D. Merry" <ken@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r249347 - head/sys/cam/ata Message-ID: <201304102212.r3AMCMxk097062@svn.freebsd.org>
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Author: ken Date: Wed Apr 10 22:12:21 2013 New Revision: 249347 URL: http://svnweb.freebsd.org/changeset/base/249347 Log: Add a callback to the ada(4) driver so that it knows when GEOM has released references to it. This is the functional equivalent to change r237518, which added this functionality to the cd(4) and da(4) drivers. This fix prevents a panic caused by GEOM calling adaopen() while the device is going away. We now keep the device around until GEOM has finished cleaning up its state. ata_da.c: In adaregister(), add a d_gone callback to the GEOM disk structure registered for the ada driver. Increment the peripheral reference count for GEOM. Add a new callback, adadiskgonecb(), that GEOM calls when it is done with its resources. This callback releases the reference acquired in adaregister(). Submitted by: Po-Li Soong Sponsored by: Spectra Logic MFC After: 5 days Modified: head/sys/cam/ata/ata_da.c Modified: head/sys/cam/ata/ata_da.c ============================================================================== --- head/sys/cam/ata/ata_da.c Wed Apr 10 20:38:15 2013 (r249346) +++ head/sys/cam/ata/ata_da.c Wed Apr 10 22:12:21 2013 (r249347) @@ -801,6 +801,20 @@ adainit(void) } } +/* + * Callback from GEOM, called when it has finished cleaning up its + * resources. + */ +static void +adadiskgonecb(struct disk *dp) +{ + struct cam_periph *periph; + + periph = (struct cam_periph *)dp->d_drv1; + + cam_periph_release(periph); +} + static void adaoninvalidate(struct cam_periph *periph) { @@ -1157,6 +1171,7 @@ adaregister(struct cam_periph *periph, v softc->disk->d_strategy = adastrategy; softc->disk->d_getattr = adagetattr; softc->disk->d_dump = adadump; + softc->disk->d_gone = adadiskgonecb; softc->disk->d_name = "ada"; softc->disk->d_drv1 = periph; maxio = cpi.maxio; /* Honor max I/O size of SIM */ @@ -1222,6 +1237,17 @@ adaregister(struct cam_periph *periph, v } } else legacy_id = -1; + /* + * Acquire a reference to the periph before we register with GEOM. + * We'll release this reference once GEOM calls us back (via + * adadiskgonecb()) telling us that our provider has been freed. + */ + if (cam_periph_acquire(periph) != CAM_REQ_CMP) { + xpt_print(periph->path, "%s: lost periph during " + "registration!\n", __func__); + cam_periph_lock(periph); + return (CAM_REQ_CMP_ERR); + } disk_create(softc->disk, DISK_VERSION); cam_periph_lock(periph); cam_periph_unhold(periph);
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