Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764227AbZCaXWh (ORCPT ); Tue, 31 Mar 2009 19:22:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758976AbZCaXUY (ORCPT ); Tue, 31 Mar 2009 19:20:24 -0400 Received: from sous-sol.org ([216.99.217.87]:33119 "EHLO x200.localdomain" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759042AbZCaXUU (ORCPT ); Tue, 31 Mar 2009 19:20:20 -0400 Message-Id: <20090331231609.657243922@sous-sol.org> User-Agent: quilt/0.47-1 Date: Tue, 31 Mar 2009 16:11:10 -0700 From: Chris Wright To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Tony Battersby , FUJITA Tomonori , Douglas Gilbert , James Bottomley Subject: [patch 25/45] SCSI: sg: fix races during device removal References: <20090331231045.719396245@sous-sol.org> Content-Disposition: inline; filename=scsi-sg-fix-races-during-device-removal.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 22572 Lines: 743 -stable review patch. If anyone has any objections, please let us know. --------------------- From: Tony Battersby upstream commit: c6517b7942fad663cc1cf3235cbe4207cf769332 sg has the following problems related to device removal: * opening a sg fd races with removing a device * closing a sg fd races with removing a device * /proc/scsi/sg/* access races with removing a device * command completion races with removing a device * command completion races with closing a sg fd * can rmmod sg with active commands These problems can cause kernel oopses, memory-use-after-free, or double-free errors. This patch fixes these problems by using krefs to manage the lifetime of sg_device and sg_fd. Each command submitted to the midlevel holds a reference to sg_fd until the completion callback. This ensures that sg_fd doesn't go away if the fd is closed with commands still outstanding. sg_fd gets the reference of sg_device (with scsi_device) and also makes sure that the sg module doesn't go away. /proc/scsi/sg/* functions don't play nicely with krefs because they give information about sg_fds which have been closed but not yet freed due to still having outstanding commands and sg_devices which have been removed but not yet freed due to still being referenced by one or more sg_fds. To deal with this safely without removing functionality, /proc functions now access sg_device and sg_fd while holding a lock instead of using kref_get()/kref_put(). Signed-off-by: Tony Battersby Acked-by: Douglas Gilbert Signed-off-by: James Bottomley Signed-off-by: Chris Wright --- drivers/scsi/sg.c | 418 +++++++++++++++++++++++++----------------------------- 1 file changed, 201 insertions(+), 217 deletions(-) --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -101,6 +101,7 @@ static int scatter_elem_sz_prev = SG_SCA #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1) static int sg_add(struct device *, struct class_interface *); +static void sg_device_destroy(struct kref *kref); static void sg_remove(struct device *, struct class_interface *); static DEFINE_IDR(sg_index_idr); @@ -158,6 +159,8 @@ typedef struct sg_fd { /* holds the sta char next_cmd_len; /* 0 -> automatic (def), >0 -> use on next write() */ char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */ char mmap_called; /* 0 -> mmap() never called on this fd */ + struct kref f_ref; + struct execute_work ew; } Sg_fd; typedef struct sg_device { /* holds the state of each scsi generic device */ @@ -171,6 +174,7 @@ typedef struct sg_device { /* holds the char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */ struct gendisk *disk; struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg] */ + struct kref d_ref; } Sg_device; static int sg_fasync(int fd, struct file *filp, int mode); @@ -194,13 +198,14 @@ static void sg_build_reserve(Sg_fd * sfp static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size); static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp); static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev); -static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp); -static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp); +static void sg_remove_sfp(struct kref *); static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id); static Sg_request *sg_add_request(Sg_fd * sfp); static int sg_remove_request(Sg_fd * sfp, Sg_request * srp); static int sg_res_in_use(Sg_fd * sfp); +static Sg_device *sg_lookup_dev(int dev); static Sg_device *sg_get_dev(int dev); +static void sg_put_dev(Sg_device *sdp); #ifdef CONFIG_SCSI_PROC_FS static int sg_last_dev(void); #endif @@ -237,22 +242,17 @@ sg_open(struct inode *inode, struct file nonseekable_open(inode, filp); SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags)); sdp = sg_get_dev(dev); - if ((!sdp) || (!sdp->device)) { - unlock_kernel(); - return -ENXIO; - } - if (sdp->detached) { - unlock_kernel(); - return -ENODEV; + if (IS_ERR(sdp)) { + retval = PTR_ERR(sdp); + sdp = NULL; + goto sg_put; } /* This driver's module count bumped by fops_get in */ /* Prevent the device driver from vanishing while we sleep */ retval = scsi_device_get(sdp->device); - if (retval) { - unlock_kernel(); - return retval; - } + if (retval) + goto sg_put; if (!((flags & O_NONBLOCK) || scsi_block_when_processing_errors(sdp->device))) { @@ -303,16 +303,20 @@ sg_open(struct inode *inode, struct file if ((sfp = sg_add_sfp(sdp, dev))) filp->private_data = sfp; else { - if (flags & O_EXCL) + if (flags & O_EXCL) { sdp->exclude = 0; /* undo if error */ + wake_up_interruptible(&sdp->o_excl_wait); + } retval = -ENOMEM; goto error_out; } - unlock_kernel(); - return 0; - - error_out: - scsi_device_put(sdp->device); + retval = 0; +error_out: + if (retval) + scsi_device_put(sdp->device); +sg_put: + if (sdp) + sg_put_dev(sdp); unlock_kernel(); return retval; } @@ -327,13 +331,13 @@ sg_release(struct inode *inode, struct f if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name)); - if (0 == sg_remove_sfp(sdp, sfp)) { /* Returns 1 when sdp gone */ - if (!sdp->detached) { - scsi_device_put(sdp->device); - } - sdp->exclude = 0; - wake_up_interruptible(&sdp->o_excl_wait); - } + + sfp->closed = 1; + + sdp->exclude = 0; + wake_up_interruptible(&sdp->o_excl_wait); + + kref_put(&sfp->f_ref, sg_remove_sfp); return 0; } @@ -755,6 +759,7 @@ sg_common_write(Sg_fd * sfp, Sg_request hp->duration = jiffies_to_msecs(jiffies); srp->rq->timeout = timeout; + kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */ blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk, srp->rq, 1, sg_rq_end_io); return 0; @@ -1247,24 +1252,23 @@ sg_mmap(struct file *filp, struct vm_are static void sg_rq_end_io(struct request *rq, int uptodate) { struct sg_request *srp = rq->end_io_data; - Sg_device *sdp = NULL; + Sg_device *sdp; Sg_fd *sfp; unsigned long iflags; unsigned int ms; char *sense; - int result, resid; + int result, resid, done = 1; - if (NULL == srp) { - printk(KERN_ERR "sg_cmd_done: NULL request\n"); + if (WARN_ON(srp->done != 0)) return; - } + sfp = srp->parentfp; - if (sfp) - sdp = sfp->parentdp; - if ((NULL == sdp) || sdp->detached) { - printk(KERN_INFO "sg_cmd_done: device detached\n"); + if (WARN_ON(sfp == NULL)) return; - } + + sdp = sfp->parentdp; + if (unlikely(sdp->detached)) + printk(KERN_INFO "sg_rq_end_io: device detached\n"); sense = rq->sense; result = rq->errors; @@ -1303,33 +1307,26 @@ static void sg_rq_end_io(struct request } /* Rely on write phase to clean out srp status values, so no "else" */ - if (sfp->closed) { /* whoops this fd already released, cleanup */ - SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n")); - sg_finish_rem_req(srp); - srp = NULL; - if (NULL == sfp->headrp) { - SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n")); - if (0 == sg_remove_sfp(sdp, sfp)) { /* device still present */ - scsi_device_put(sdp->device); - } - sfp = NULL; - } - } else if (srp && srp->orphan) { + write_lock_irqsave(&sfp->rq_list_lock, iflags); + if (unlikely(srp->orphan)) { if (sfp->keep_orphan) srp->sg_io_owned = 0; - else { - sg_finish_rem_req(srp); - srp = NULL; - } + else + done = 0; } - if (sfp && srp) { - /* Now wake up any sg_read() that is waiting for this packet. */ - kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN); - write_lock_irqsave(&sfp->rq_list_lock, iflags); - srp->done = 1; + srp->done = done; + write_unlock_irqrestore(&sfp->rq_list_lock, iflags); + + if (likely(done)) { + /* Now wake up any sg_read() that is waiting for this + * packet. + */ wake_up_interruptible(&sfp->read_wait); - write_unlock_irqrestore(&sfp->rq_list_lock, iflags); - } + kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN); + } else + sg_finish_rem_req(srp); /* call with srp->done == 0 */ + + kref_put(&sfp->f_ref, sg_remove_sfp); } static struct file_operations sg_fops = { @@ -1364,17 +1361,18 @@ static Sg_device *sg_alloc(struct gendis printk(KERN_WARNING "kmalloc Sg_device failure\n"); return ERR_PTR(-ENOMEM); } - error = -ENOMEM; + if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) { printk(KERN_WARNING "idr expansion Sg_device failure\n"); + error = -ENOMEM; goto out; } write_lock_irqsave(&sg_index_lock, iflags); - error = idr_get_new(&sg_index_idr, sdp, &k); - write_unlock_irqrestore(&sg_index_lock, iflags); + error = idr_get_new(&sg_index_idr, sdp, &k); if (error) { + write_unlock_irqrestore(&sg_index_lock, iflags); printk(KERN_WARNING "idr allocation Sg_device failure: %d\n", error); goto out; @@ -1391,6 +1389,9 @@ static Sg_device *sg_alloc(struct gendis init_waitqueue_head(&sdp->o_excl_wait); sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments); sdp->index = k; + kref_init(&sdp->d_ref); + + write_unlock_irqrestore(&sg_index_lock, iflags); error = 0; out: @@ -1401,6 +1402,8 @@ static Sg_device *sg_alloc(struct gendis return sdp; overflow: + idr_remove(&sg_index_idr, k); + write_unlock_irqrestore(&sg_index_lock, iflags); sdev_printk(KERN_WARNING, scsidp, "Unable to attach sg device type=%d, minor " "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1); @@ -1488,49 +1491,46 @@ out: return error; } -static void -sg_remove(struct device *cl_dev, struct class_interface *cl_intf) +static void sg_device_destroy(struct kref *kref) +{ + struct sg_device *sdp = container_of(kref, struct sg_device, d_ref); + unsigned long flags; + + /* CAUTION! Note that the device can still be found via idr_find() + * even though the refcount is 0. Therefore, do idr_remove() BEFORE + * any other cleanup. + */ + + write_lock_irqsave(&sg_index_lock, flags); + idr_remove(&sg_index_idr, sdp->index); + write_unlock_irqrestore(&sg_index_lock, flags); + + SCSI_LOG_TIMEOUT(3, + printk("sg_device_destroy: %s\n", + sdp->disk->disk_name)); + + put_disk(sdp->disk); + kfree(sdp); +} + +static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf) { struct scsi_device *scsidp = to_scsi_device(cl_dev->parent); Sg_device *sdp = dev_get_drvdata(cl_dev); unsigned long iflags; Sg_fd *sfp; - Sg_fd *tsfp; - Sg_request *srp; - Sg_request *tsrp; - int delay; - if (!sdp) + if (!sdp || sdp->detached) return; - delay = 0; + SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name)); + + /* Need a write lock to set sdp->detached. */ write_lock_irqsave(&sg_index_lock, iflags); - if (sdp->headfp) { - sdp->detached = 1; - for (sfp = sdp->headfp; sfp; sfp = tsfp) { - tsfp = sfp->nextfp; - for (srp = sfp->headrp; srp; srp = tsrp) { - tsrp = srp->nextrp; - if (sfp->closed || (0 == sg_srp_done(srp, sfp))) - sg_finish_rem_req(srp); - } - if (sfp->closed) { - scsi_device_put(sdp->device); - __sg_remove_sfp(sdp, sfp); - } else { - delay = 1; - wake_up_interruptible(&sfp->read_wait); - kill_fasync(&sfp->async_qp, SIGPOLL, - POLL_HUP); - } - } - SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index)); - if (NULL == sdp->headfp) { - idr_remove(&sg_index_idr, sdp->index); - } - } else { /* nothing active, simple case */ - SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index)); - idr_remove(&sg_index_idr, sdp->index); + sdp->detached = 1; + for (sfp = sdp->headfp; sfp; sfp = sfp->nextfp) { + wake_up_interruptible(&sfp->read_wait); + kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP); } write_unlock_irqrestore(&sg_index_lock, iflags); @@ -1538,13 +1538,8 @@ sg_remove(struct device *cl_dev, struct device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index)); cdev_del(sdp->cdev); sdp->cdev = NULL; - put_disk(sdp->disk); - sdp->disk = NULL; - if (NULL == sdp->headfp) - kfree(sdp); - if (delay) - msleep(10); /* dirty detach so delay device destruction */ + sg_put_dev(sdp); } module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR); @@ -1941,22 +1936,6 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id) return resp; } -#ifdef CONFIG_SCSI_PROC_FS -static Sg_request * -sg_get_nth_request(Sg_fd * sfp, int nth) -{ - Sg_request *resp; - unsigned long iflags; - int k; - - read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (k = 0, resp = sfp->headrp; resp && (k < nth); - ++k, resp = resp->nextrp) ; - read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - return resp; -} -#endif - /* always adds to end of list */ static Sg_request * sg_add_request(Sg_fd * sfp) @@ -2032,22 +2011,6 @@ sg_remove_request(Sg_fd * sfp, Sg_reques return res; } -#ifdef CONFIG_SCSI_PROC_FS -static Sg_fd * -sg_get_nth_sfp(Sg_device * sdp, int nth) -{ - Sg_fd *resp; - unsigned long iflags; - int k; - - read_lock_irqsave(&sg_index_lock, iflags); - for (k = 0, resp = sdp->headfp; resp && (k < nth); - ++k, resp = resp->nextfp) ; - read_unlock_irqrestore(&sg_index_lock, iflags); - return resp; -} -#endif - static Sg_fd * sg_add_sfp(Sg_device * sdp, int dev) { @@ -2062,6 +2025,7 @@ sg_add_sfp(Sg_device * sdp, int dev) init_waitqueue_head(&sfp->read_wait); rwlock_init(&sfp->rq_list_lock); + kref_init(&sfp->f_ref); sfp->timeout = SG_DEFAULT_TIMEOUT; sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER; sfp->force_packid = SG_DEF_FORCE_PACK_ID; @@ -2089,15 +2053,54 @@ sg_add_sfp(Sg_device * sdp, int dev) sg_build_reserve(sfp, bufflen); SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: bufflen=%d, k_use_sg=%d\n", sfp->reserve.bufflen, sfp->reserve.k_use_sg)); + + kref_get(&sdp->d_ref); + __module_get(THIS_MODULE); return sfp; } -static void -__sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp) +static void sg_remove_sfp_usercontext(struct work_struct *work) +{ + struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work); + struct sg_device *sdp = sfp->parentdp; + + /* Cleanup any responses which were never read(). */ + while (sfp->headrp) + sg_finish_rem_req(sfp->headrp); + + if (sfp->reserve.bufflen > 0) { + SCSI_LOG_TIMEOUT(6, + printk("sg_remove_sfp: bufflen=%d, k_use_sg=%d\n", + (int) sfp->reserve.bufflen, + (int) sfp->reserve.k_use_sg)); + sg_remove_scat(&sfp->reserve); + } + + SCSI_LOG_TIMEOUT(6, + printk("sg_remove_sfp: %s, sfp=0x%p\n", + sdp->disk->disk_name, + sfp)); + kfree(sfp); + + scsi_device_put(sdp->device); + sg_put_dev(sdp); + module_put(THIS_MODULE); +} + +static void sg_remove_sfp(struct kref *kref) { + struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref); + struct sg_device *sdp = sfp->parentdp; Sg_fd *fp; Sg_fd *prev_fp; + unsigned long iflags; + + /* CAUTION! Note that sfp can still be found by walking sdp->headfp + * even though the refcount is now 0. Therefore, unlink sfp from + * sdp->headfp BEFORE doing any other cleanup. + */ + write_lock_irqsave(&sg_index_lock, iflags); prev_fp = sdp->headfp; if (sfp == prev_fp) sdp->headfp = prev_fp->nextfp; @@ -2110,54 +2113,10 @@ __sg_remove_sfp(Sg_device * sdp, Sg_fd * prev_fp = fp; } } - if (sfp->reserve.bufflen > 0) { - SCSI_LOG_TIMEOUT(6, - printk("__sg_remove_sfp: bufflen=%d, k_use_sg=%d\n", - (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg)); - sg_remove_scat(&sfp->reserve); - } - sfp->parentdp = NULL; - SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp: sfp=0x%p\n", sfp)); - kfree(sfp); -} - -/* Returns 0 in normal case, 1 when detached and sdp object removed */ -static int -sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp) -{ - Sg_request *srp; - Sg_request *tsrp; - int dirty = 0; - int res = 0; - - for (srp = sfp->headrp; srp; srp = tsrp) { - tsrp = srp->nextrp; - if (sg_srp_done(srp, sfp)) - sg_finish_rem_req(srp); - else - ++dirty; - } - if (0 == dirty) { - unsigned long iflags; + write_unlock_irqrestore(&sg_index_lock, iflags); + wake_up_interruptible(&sdp->o_excl_wait); - write_lock_irqsave(&sg_index_lock, iflags); - __sg_remove_sfp(sdp, sfp); - if (sdp->detached && (NULL == sdp->headfp)) { - idr_remove(&sg_index_idr, sdp->index); - kfree(sdp); - res = 1; - } - write_unlock_irqrestore(&sg_index_lock, iflags); - } else { - /* MOD_INC's to inhibit unloading sg and associated adapter driver */ - /* only bump the access_count if we actually succeeded in - * throwing another counter on the host module */ - scsi_device_get(sdp->device); /* XXX: retval ignored? */ - sfp->closed = 1; /* flag dirty state on this fd */ - SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n", - dirty)); - } - return res; + execute_in_process_context(sg_remove_sfp_usercontext, &sfp->ew); } static int @@ -2199,19 +2158,38 @@ sg_last_dev(void) } #endif -static Sg_device * -sg_get_dev(int dev) +/* must be called with sg_index_lock held */ +static Sg_device *sg_lookup_dev(int dev) { - Sg_device *sdp; - unsigned long iflags; + return idr_find(&sg_index_idr, dev); +} - read_lock_irqsave(&sg_index_lock, iflags); - sdp = idr_find(&sg_index_idr, dev); - read_unlock_irqrestore(&sg_index_lock, iflags); +static Sg_device *sg_get_dev(int dev) +{ + struct sg_device *sdp; + unsigned long flags; + + read_lock_irqsave(&sg_index_lock, flags); + sdp = sg_lookup_dev(dev); + if (!sdp) + sdp = ERR_PTR(-ENXIO); + else if (sdp->detached) { + /* If sdp->detached, then the refcount may already be 0, in + * which case it would be a bug to do kref_get(). + */ + sdp = ERR_PTR(-ENODEV); + } else + kref_get(&sdp->d_ref); + read_unlock_irqrestore(&sg_index_lock, flags); return sdp; } +static void sg_put_dev(struct sg_device *sdp) +{ + kref_put(&sdp->d_ref, sg_device_destroy); +} + #ifdef CONFIG_SCSI_PROC_FS static struct proc_dir_entry *sg_proc_sgp = NULL; @@ -2468,8 +2446,10 @@ static int sg_proc_seq_show_dev(struct s struct sg_proc_deviter * it = (struct sg_proc_deviter *) v; Sg_device *sdp; struct scsi_device *scsidp; + unsigned long iflags; - sdp = it ? sg_get_dev(it->index) : NULL; + read_lock_irqsave(&sg_index_lock, iflags); + sdp = it ? sg_lookup_dev(it->index) : NULL; if (sdp && (scsidp = sdp->device) && (!sdp->detached)) seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n", scsidp->host->host_no, scsidp->channel, @@ -2480,6 +2460,7 @@ static int sg_proc_seq_show_dev(struct s (int) scsi_device_online(scsidp)); else seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n"); + read_unlock_irqrestore(&sg_index_lock, iflags); return 0; } @@ -2493,16 +2474,20 @@ static int sg_proc_seq_show_devstrs(stru struct sg_proc_deviter * it = (struct sg_proc_deviter *) v; Sg_device *sdp; struct scsi_device *scsidp; + unsigned long iflags; - sdp = it ? sg_get_dev(it->index) : NULL; + read_lock_irqsave(&sg_index_lock, iflags); + sdp = it ? sg_lookup_dev(it->index) : NULL; if (sdp && (scsidp = sdp->device) && (!sdp->detached)) seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n", scsidp->vendor, scsidp->model, scsidp->rev); else seq_printf(s, "\n"); + read_unlock_irqrestore(&sg_index_lock, iflags); return 0; } +/* must be called while holding sg_index_lock */ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) { int k, m, new_interface, blen, usg; @@ -2512,7 +2497,8 @@ static void sg_proc_debug_helper(struct const char * cp; unsigned int ms; - for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) { + for (k = 0, fp = sdp->headfp; fp != NULL; ++k, fp = fp->nextfp) { + read_lock(&fp->rq_list_lock); /* irqs already disabled */ seq_printf(s, " FD(%d): timeout=%dms bufflen=%d " "(res)sgat=%d low_dma=%d\n", k + 1, jiffies_to_msecs(fp->timeout), @@ -2522,7 +2508,9 @@ static void sg_proc_debug_helper(struct seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n", (int) fp->cmd_q, (int) fp->force_packid, (int) fp->keep_orphan, (int) fp->closed); - for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) { + for (m = 0, srp = fp->headrp; + srp != NULL; + ++m, srp = srp->nextrp) { hp = &srp->header; new_interface = (hp->interface_id == '\0') ? 0 : 1; if (srp->res_used) { @@ -2559,6 +2547,7 @@ static void sg_proc_debug_helper(struct } if (0 == m) seq_printf(s, " No requests active\n"); + read_unlock(&fp->rq_list_lock); } } @@ -2571,39 +2560,34 @@ static int sg_proc_seq_show_debug(struct { struct sg_proc_deviter * it = (struct sg_proc_deviter *) v; Sg_device *sdp; + unsigned long iflags; if (it && (0 == it->index)) { seq_printf(s, "max_active_device=%d(origin 1)\n", (int)it->max); seq_printf(s, " def_reserved_size=%d\n", sg_big_buff); } - sdp = it ? sg_get_dev(it->index) : NULL; - if (sdp) { - struct scsi_device *scsidp = sdp->device; - if (NULL == scsidp) { - seq_printf(s, "device %d detached ??\n", - (int)it->index); - return 0; - } + read_lock_irqsave(&sg_index_lock, iflags); + sdp = it ? sg_lookup_dev(it->index) : NULL; + if (sdp && sdp->headfp) { + struct scsi_device *scsidp = sdp->device; - if (sg_get_nth_sfp(sdp, 0)) { - seq_printf(s, " >>> device=%s ", - sdp->disk->disk_name); - if (sdp->detached) - seq_printf(s, "detached pending close "); - else - seq_printf - (s, "scsi%d chan=%d id=%d lun=%d em=%d", - scsidp->host->host_no, - scsidp->channel, scsidp->id, - scsidp->lun, - scsidp->host->hostt->emulated); - seq_printf(s, " sg_tablesize=%d excl=%d\n", - sdp->sg_tablesize, sdp->exclude); - } + seq_printf(s, " >>> device=%s ", sdp->disk->disk_name); + if (sdp->detached) + seq_printf(s, "detached pending close "); + else + seq_printf + (s, "scsi%d chan=%d id=%d lun=%d em=%d", + scsidp->host->host_no, + scsidp->channel, scsidp->id, + scsidp->lun, + scsidp->host->hostt->emulated); + seq_printf(s, " sg_tablesize=%d excl=%d\n", + sdp->sg_tablesize, sdp->exclude); sg_proc_debug_helper(s, sdp); } + read_unlock_irqrestore(&sg_index_lock, iflags); return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/