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path: root/drivers/scsi/sg.c
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Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r--drivers/scsi/sg.c280
1 files changed, 142 insertions, 138 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 909ed9ed24c..53268aaba55 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -35,6 +35,7 @@ static int sg_version_num = 30534; /* 2 digits for each component */
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
+#include <linux/aio.h>
#include <linux/errno.h>
#include <linux/mtio.h>
#include <linux/ioctl.h>
@@ -50,6 +51,7 @@ static int sg_version_num = 30534; /* 2 digits for each component */
#include <linux/delay.h>
#include <linux/blktrace_api.h>
#include <linux/mutex.h>
+#include <linux/ratelimit.h>
#include "scsi.h"
#include <scsi/scsi_dbg.h>
@@ -103,7 +105,7 @@ static int scatter_elem_sz_prev = SG_SCATTER_SZ;
static int sg_add(struct device *, struct class_interface *);
static void sg_remove(struct device *, struct class_interface *);
-static DEFINE_MUTEX(sg_mutex);
+static DEFINE_SPINLOCK(sg_open_exclusive_lock);
static DEFINE_IDR(sg_index_idr);
static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
@@ -136,13 +138,15 @@ typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
- volatile char done; /* 0->before bh, 1->before read, 2->read */
+ /* done protected by rq_list_lock */
+ char done; /* 0->before bh, 1->before read, 2->read */
struct request *rq;
struct bio *bio;
struct execute_work ew;
} Sg_request;
typedef struct sg_fd { /* holds the state of a file descriptor */
+ /* sfd_siblings is protected by sg_index_lock */
struct list_head sfd_siblings;
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
@@ -156,7 +160,6 @@ typedef struct sg_fd { /* holds the state of a file descriptor */
Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
char low_dma; /* as in parent but possibly overridden to 1 */
char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
- volatile char closed; /* 1 -> fd closed but request(s) outstanding */
char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
char next_cmd_len; /* 0 -> automatic (def), >0 -> use on next write() */
char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
@@ -170,9 +173,11 @@ 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 */
+ /* sfds is protected by sg_index_lock */
struct list_head sfds;
volatile char detached; /* 0->attached, 1->detached pending removal */
- volatile char exclude; /* opened for exclusive access */
+ /* exclude protected by sg_open_exclusive_lock */
+ char exclude; /* opened for exclusive access */
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<n>] */
@@ -220,6 +225,38 @@ static int sg_allow_access(struct file *filp, unsigned char *cmd)
return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
}
+static int get_exclude(Sg_device *sdp)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&sg_open_exclusive_lock, flags);
+ ret = sdp->exclude;
+ spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
+ return ret;
+}
+
+static int set_exclude(Sg_device *sdp, char val)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sg_open_exclusive_lock, flags);
+ sdp->exclude = val;
+ spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
+ return val;
+}
+
+static int sfds_list_empty(Sg_device *sdp)
+{
+ unsigned long flags;
+ int ret;
+
+ read_lock_irqsave(&sg_index_lock, flags);
+ ret = list_empty(&sdp->sfds);
+ read_unlock_irqrestore(&sg_index_lock, flags);
+ return ret;
+}
+
static int
sg_open(struct inode *inode, struct file *filp)
{
@@ -231,7 +268,6 @@ sg_open(struct inode *inode, struct file *filp)
int res;
int retval;
- mutex_lock(&sg_mutex);
nonseekable_open(inode, filp);
SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
sdp = sg_get_dev(dev);
@@ -263,25 +299,22 @@ sg_open(struct inode *inode, struct file *filp)
retval = -EPERM; /* Can't lock it with read only access */
goto error_out;
}
- if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
+ if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) {
retval = -EBUSY;
goto error_out;
}
- res = 0;
- __wait_event_interruptible(sdp->o_excl_wait,
- ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
+ res = wait_event_interruptible(sdp->o_excl_wait,
+ ((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1)));
if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out;
}
- } else if (sdp->exclude) { /* some other fd has an exclusive lock on dev */
+ } else if (get_exclude(sdp)) { /* some other fd has an exclusive lock on dev */
if (flags & O_NONBLOCK) {
retval = -EBUSY;
goto error_out;
}
- res = 0;
- __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
- res);
+ res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp));
if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out;
@@ -291,7 +324,7 @@ sg_open(struct inode *inode, struct file *filp)
retval = -ENODEV;
goto error_out;
}
- if (list_empty(&sdp->sfds)) { /* no existing opens on this device */
+ if (sfds_list_empty(sdp)) { /* no existing opens on this device */
sdp->sgdebug = 0;
q = sdp->device->request_queue;
sdp->sg_tablesize = queue_max_segments(q);
@@ -300,7 +333,7 @@ sg_open(struct inode *inode, struct file *filp)
filp->private_data = sfp;
else {
if (flags & O_EXCL) {
- sdp->exclude = 0; /* undo if error */
+ set_exclude(sdp, 0); /* undo if error */
wake_up_interruptible(&sdp->o_excl_wait);
}
retval = -ENOMEM;
@@ -316,7 +349,6 @@ sdp_put:
sg_put:
if (sdp)
sg_put_dev(sdp);
- mutex_unlock(&sg_mutex);
return retval;
}
@@ -331,9 +363,7 @@ sg_release(struct inode *inode, struct file *filp)
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
- sfp->closed = 1;
-
- sdp->exclude = 0;
+ set_exclude(sdp, 0);
wake_up_interruptible(&sdp->o_excl_wait);
scsi_autopm_put_device(sdp->device);
@@ -397,19 +427,14 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
retval = -EAGAIN;
goto free_old_hdr;
}
- while (1) {
- retval = 0; /* following macro beats race condition */
- __wait_event_interruptible(sfp->read_wait,
- (sdp->detached ||
- (srp = sg_get_rq_mark(sfp, req_pack_id))),
- retval);
- if (sdp->detached) {
- retval = -ENODEV;
- goto free_old_hdr;
- }
- if (0 == retval)
- break;
-
+ retval = wait_event_interruptible(sfp->read_wait,
+ (sdp->detached ||
+ (srp = sg_get_rq_mark(sfp, req_pack_id))));
+ if (sdp->detached) {
+ retval = -ENODEV;
+ goto free_old_hdr;
+ }
+ if (retval) {
/* -ERESTARTSYS as signal hit process */
goto free_old_hdr;
}
@@ -626,14 +651,15 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
*/
if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
static char cmd[TASK_COMM_LEN];
- if (strcmp(current->comm, cmd) && printk_ratelimit()) {
- printk(KERN_WARNING
- "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
- "guessing data in;\n "
- "program %s not setting count and/or reply_len properly\n",
- old_hdr.reply_len - (int)SZ_SG_HEADER,
- input_size, (unsigned int) cmnd[0],
- current->comm);
+ if (strcmp(current->comm, cmd)) {
+ printk_ratelimited(KERN_WARNING
+ "sg_write: data in/out %d/%d bytes "
+ "for SCSI command 0x%x-- guessing "
+ "data in;\n program %s not setting "
+ "count and/or reply_len properly\n",
+ old_hdr.reply_len - (int)SZ_SG_HEADER,
+ input_size, (unsigned int) cmnd[0],
+ current->comm);
strcpy(cmd, current->comm);
}
}
@@ -769,7 +795,18 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
return 0;
}
-static int
+static int srp_done(Sg_fd *sfp, Sg_request *srp)
+{
+ unsigned long flags;
+ int ret;
+
+ read_lock_irqsave(&sfp->rq_list_lock, flags);
+ ret = srp->done;
+ read_unlock_irqrestore(&sfp->rq_list_lock, flags);
+ return ret;
+}
+
+static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
void __user *p = (void __user *)arg;
@@ -789,40 +826,30 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
switch (cmd_in) {
case SG_IO:
- {
- int blocking = 1; /* ignore O_NONBLOCK flag */
-
- if (sdp->detached)
- return -ENODEV;
- if (!scsi_block_when_processing_errors(sdp->device))
- return -ENXIO;
- if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
- return -EFAULT;
- result =
- sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
- blocking, read_only, 1, &srp);
- if (result < 0)
- return result;
- while (1) {
- result = 0; /* following macro to beat race condition */
- __wait_event_interruptible(sfp->read_wait,
- (srp->done || sdp->detached),
- result);
- if (sdp->detached)
- return -ENODEV;
- write_lock_irq(&sfp->rq_list_lock);
- if (srp->done) {
- srp->done = 2;
- write_unlock_irq(&sfp->rq_list_lock);
- break;
- }
- srp->orphan = 1;
- write_unlock_irq(&sfp->rq_list_lock);
- return result; /* -ERESTARTSYS because signal hit process */
- }
+ if (sdp->detached)
+ return -ENODEV;
+ if (!scsi_block_when_processing_errors(sdp->device))
+ return -ENXIO;
+ if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
+ return -EFAULT;
+ result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
+ 1, read_only, 1, &srp);
+ if (result < 0)
+ return result;
+ result = wait_event_interruptible(sfp->read_wait,
+ (srp_done(sfp, srp) || sdp->detached));
+ if (sdp->detached)
+ return -ENODEV;
+ write_lock_irq(&sfp->rq_list_lock);
+ if (srp->done) {
+ srp->done = 2;
+ write_unlock_irq(&sfp->rq_list_lock);
result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
return (result < 0) ? result : 0;
}
+ srp->orphan = 1;
+ write_unlock_irq(&sfp->rq_list_lock);
+ return result; /* -ERESTARTSYS because signal hit process */
case SG_SET_TIMEOUT:
result = get_user(val, ip);
if (result)
@@ -1089,18 +1116,6 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
}
}
-static long
-sg_unlocked_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
-{
- int ret;
-
- mutex_lock(&sg_mutex);
- ret = sg_ioctl(filp, cmd_in, arg);
- mutex_unlock(&sg_mutex);
-
- return ret;
-}
-
#ifdef CONFIG_COMPAT
static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
@@ -1134,8 +1149,11 @@ sg_poll(struct file *filp, poll_table * wait)
int count = 0;
unsigned long iflags;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
- || sfp->closed)
+ sfp = filp->private_data;
+ if (!sfp)
+ return POLLERR;
+ sdp = sfp->parentdp;
+ if (!sdp)
return POLLERR;
poll_wait(filp, &sfp->read_wait, wait);
read_lock_irqsave(&sfp->rq_list_lock, iflags);
@@ -1240,7 +1258,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
}
sfp->mmap_called = 1;
- vma->vm_flags |= VM_RESERVED;
+ vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_private_data = sfp;
vma->vm_ops = &sg_mmap_vm_ops;
return 0;
@@ -1345,7 +1363,7 @@ static const struct file_operations sg_fops = {
.read = sg_read,
.write = sg_write,
.poll = sg_poll,
- .unlocked_ioctl = sg_unlocked_ioctl,
+ .unlocked_ioctl = sg_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = sg_compat_ioctl,
#endif
@@ -1374,24 +1392,23 @@ static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
return ERR_PTR(-ENOMEM);
}
- if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
- printk(KERN_WARNING "idr expansion Sg_device failure\n");
- error = -ENOMEM;
- goto out;
- }
-
+ idr_preload(GFP_KERNEL);
write_lock_irqsave(&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;
+ error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
+ if (error < 0) {
+ if (error == -ENOSPC) {
+ sdev_printk(KERN_WARNING, scsidp,
+ "Unable to attach sg device type=%d, minor number exceeds %d\n",
+ scsidp->type, SG_MAX_DEVS - 1);
+ error = -ENODEV;
+ } else {
+ printk(KERN_WARNING
+ "idr allocation Sg_device failure: %d\n", error);
+ }
+ goto out_unlock;
}
-
- if (unlikely(k >= SG_MAX_DEVS))
- goto overflow;
+ k = error;
SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
sprintf(disk->disk_name, "sg%d", k);
@@ -1403,25 +1420,17 @@ static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
sdp->sg_tablesize = queue_max_segments(q);
sdp->index = k;
kref_init(&sdp->d_ref);
+ error = 0;
+out_unlock:
write_unlock_irqrestore(&sg_index_lock, iflags);
+ idr_preload_end();
- error = 0;
- out:
if (error) {
kfree(sdp);
return ERR_PTR(error);
}
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);
- error = -ENODEV;
- goto out;
}
static int
@@ -1644,10 +1653,9 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
if (!rq)
return -ENOMEM;
+ blk_rq_set_block_pc(rq);
memcpy(rq->cmd, cmd, hp->cmd_len);
-
rq->cmd_len = hp->cmd_len;
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
srp->rq = rq;
rq->end_io_data = srp;
@@ -2310,7 +2318,7 @@ struct sg_proc_leaf {
const struct file_operations * fops;
};
-static struct sg_proc_leaf sg_proc_leaf_arr[] = {
+static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
{"allow_dio", &adio_fops},
{"debug", &debug_fops},
{"def_reserved_size", &dressz_fops},
@@ -2323,16 +2331,15 @@ static struct sg_proc_leaf sg_proc_leaf_arr[] = {
static int
sg_proc_init(void)
{
- int k, mask;
int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
- struct sg_proc_leaf * leaf;
+ int k;
sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
if (!sg_proc_sgp)
return 1;
for (k = 0; k < num_leaves; ++k) {
- leaf = &sg_proc_leaf_arr[k];
- mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
+ const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
+ umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
}
return 0;
@@ -2367,16 +2374,15 @@ static ssize_t
sg_proc_write_adio(struct file *filp, const char __user *buffer,
size_t count, loff_t *off)
{
- int num;
- char buff[11];
+ int err;
+ unsigned long num;
if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
return -EACCES;
- num = (count < 10) ? count : 10;
- if (copy_from_user(buff, buffer, num))
- return -EFAULT;
- buff[num] = '\0';
- sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
+ err = kstrtoul_from_user(buffer, count, 0, &num);
+ if (err)
+ return err;
+ sg_allow_dio = num ? 1 : 0;
return count;
}
@@ -2389,17 +2395,15 @@ static ssize_t
sg_proc_write_dressz(struct file *filp, const char __user *buffer,
size_t count, loff_t *off)
{
- int num;
+ int err;
unsigned long k = ULONG_MAX;
- char buff[11];
if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
return -EACCES;
- num = (count < 10) ? count : 10;
- if (copy_from_user(buff, buffer, num))
- return -EFAULT;
- buff[num] = '\0';
- k = simple_strtoul(buff, NULL, 10);
+
+ err = kstrtoul_from_user(buffer, count, 0, &k);
+ if (err)
+ return err;
if (k <= 1048576) { /* limit "big buff" to 1 MB */
sg_big_buff = k;
return count;
@@ -2535,9 +2539,9 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
fp->reserve.bufflen,
(int) fp->reserve.k_use_sg,
(int) fp->low_dma);
- seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
+ seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
(int) fp->cmd_q, (int) fp->force_packid,
- (int) fp->keep_orphan, (int) fp->closed);
+ (int) fp->keep_orphan);
for (m = 0, srp = fp->headrp;
srp != NULL;
++m, srp = srp->nextrp) {
@@ -2614,7 +2618,7 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
scsidp->lun,
scsidp->host->hostt->emulated);
seq_printf(s, " sg_tablesize=%d excl=%d\n",
- sdp->sg_tablesize, sdp->exclude);
+ sdp->sg_tablesize, get_exclude(sdp));
sg_proc_debug_helper(s, sdp);
}
read_unlock_irqrestore(&sg_index_lock, iflags);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-03 18:26:09 +0000