From 3442f802a8169a0c18d411d95f0e71b9205ed607 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 16 Feb 2009 13:26:53 +0900 Subject: [PATCH] [SCSI] sg: remove the own list management for struct sg_fd This replaces the own list management for struct sg_fd with the standard list_head structure. Signed-off-by: FUJITA Tomonori Acked-by: Douglas Gilbert Signed-off-by: James Bottomley --- drivers/scsi/sg.c | 50 +++++++++++++---------------------------------- 1 file changed, 14 insertions(+), 36 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index d45ac4aab92f..7bf54c9a33bb 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -140,7 +140,7 @@ typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */ } Sg_request; typedef struct sg_fd { /* holds the state of a file descriptor */ - struct sg_fd *nextfp; /* NULL when last opened fd on this device */ + struct list_head sfd_siblings; struct sg_device *parentdp; /* owning device */ wait_queue_head_t read_wait; /* queue read until command done */ rwlock_t rq_list_lock; /* protect access to list in req_arr */ @@ -167,7 +167,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */ wait_queue_head_t o_excl_wait; /* queue open() when O_EXCL in use */ int sg_tablesize; /* adapter's max scatter-gather table size */ u32 index; /* device index number */ - Sg_fd *headfp; /* first open fd belonging to this device */ + struct list_head sfds; volatile char detached; /* 0->attached, 1->detached pending removal */ volatile char exclude; /* opened for exclusive access */ char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */ @@ -258,13 +258,13 @@ sg_open(struct inode *inode, struct file *filp) retval = -EPERM; /* Can't lock it with read only access */ goto error_out; } - if (sdp->headfp && (flags & O_NONBLOCK)) { + if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) { retval = -EBUSY; goto error_out; } res = 0; __wait_event_interruptible(sdp->o_excl_wait, - ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res); + ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res); if (res) { retval = res; /* -ERESTARTSYS because signal hit process */ goto error_out; @@ -286,7 +286,7 @@ sg_open(struct inode *inode, struct file *filp) retval = -ENODEV; goto error_out; } - if (!sdp->headfp) { /* no existing opens on this device */ + if (list_empty(&sdp->sfds)) { /* no existing opens on this device */ sdp->sgdebug = 0; q = sdp->device->request_queue; sdp->sg_tablesize = min(q->max_hw_segments, @@ -1375,6 +1375,7 @@ static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp) disk->first_minor = k; sdp->disk = disk; sdp->device = scsidp; + INIT_LIST_HEAD(&sdp->sfds); init_waitqueue_head(&sdp->o_excl_wait); sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments); sdp->index = k; @@ -1517,7 +1518,7 @@ static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf) /* Need a write lock to set sdp->detached. */ write_lock_irqsave(&sg_index_lock, iflags); sdp->detached = 1; - for (sfp = sdp->headfp; sfp; sfp = sfp->nextfp) { + list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) { wake_up_interruptible(&sfp->read_wait); kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP); } @@ -2024,14 +2025,7 @@ sg_add_sfp(Sg_device * sdp, int dev) sfp->keep_orphan = SG_DEF_KEEP_ORPHAN; sfp->parentdp = sdp; write_lock_irqsave(&sg_index_lock, iflags); - if (!sdp->headfp) - sdp->headfp = sfp; - else { /* add to tail of existing list */ - Sg_fd *pfp = sdp->headfp; - while (pfp->nextfp) - pfp = pfp->nextfp; - pfp->nextfp = sfp; - } + list_add_tail(&sfp->sfd_siblings, &sdp->sfds); write_unlock_irqrestore(&sg_index_lock, iflags); SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp)); if (unlikely(sg_big_buff != def_reserved_size)) @@ -2080,28 +2074,10 @@ 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; - else { - while ((fp = prev_fp->nextfp)) { - if (sfp == fp) { - prev_fp->nextfp = fp->nextfp; - break; - } - prev_fp = fp; - } - } + list_del(&sfp->sfd_siblings); write_unlock_irqrestore(&sg_index_lock, iflags); wake_up_interruptible(&sdp->o_excl_wait); @@ -2486,10 +2462,12 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) const char * cp; unsigned int ms; - for (k = 0, fp = sdp->headfp; fp != NULL; ++k, fp = fp->nextfp) { + k = 0; + list_for_each_entry(fp, &sdp->sfds, sfd_siblings) { + k++; 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, + "(res)sgat=%d low_dma=%d\n", k, jiffies_to_msecs(fp->timeout), fp->reserve.bufflen, (int) fp->reserve.k_use_sg, @@ -2559,7 +2537,7 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v) read_lock_irqsave(&sg_index_lock, iflags); sdp = it ? sg_lookup_dev(it->index) : NULL; - if (sdp && sdp->headfp) { + if (sdp && !list_empty(&sdp->sfds)) { struct scsi_device *scsidp = sdp->device; seq_printf(s, " >>> device=%s ", sdp->disk->disk_name); -- 2.34.1