@@ -43,6 +43,7 @@ static char *sg_version_date = "20190606";
#include <linux/cred.h> /* for sg_check_file_access() */
#include <linux/proc_fs.h>
#include <linux/xarray.h>
+#include <linux/debugfs.h>
#include <scsi/scsi.h>
#include <scsi/scsi_eh.h>
@@ -67,6 +68,10 @@ static char *sg_version_date = "20190606";
#endif
#endif
+#if IS_ENABLED(CONFIG_SCSI_PROC_FS) || IS_ENABLED(CONFIG_DEBUG_FS)
+#define SG_PROC_OR_DEBUG_FS 1
+#endif
+
/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
* of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
* than 16 bytes are "variable length" whose length is a multiple of 4, so:
@@ -268,6 +273,8 @@ struct sg_comm_wr_t { /* arguments to sg_common_write() */
static void sg_rq_end_io(struct request *rq, blk_status_t status);
/* Declarations of other static functions used before they are defined */
static int sg_proc_init(void);
+static void sg_dfs_init(void);
+static void sg_dfs_exit(void);
static int sg_start_req(struct sg_request *srp, struct sg_comm_wr_t *cwrp,
int dxfer_dir);
static void sg_finish_scsi_blk_rq(struct sg_request *srp);
@@ -2732,22 +2739,6 @@ sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
kref_put(&sdp->d_ref, sg_device_destroy);
}
-module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
-module_param_named(def_reserved_size, def_reserved_size, int,
- S_IRUGO | S_IWUSR);
-module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
-
-MODULE_AUTHOR("Douglas Gilbert");
-MODULE_DESCRIPTION("SCSI generic (sg) driver");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(SG_VERSION_STR);
-MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
-
-MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
- "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
-MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
-MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
-
static int __init
init_sg(void)
{
@@ -2797,6 +2788,7 @@ init_sg(void)
rc = scsi_register_interface(&sg_interface);
if (rc == 0) {
sg_proc_init();
+ sg_dfs_init();
return 0;
}
class_destroy(sg_sysfs_class);
@@ -2810,17 +2802,10 @@ init_sg(void)
return rc;
}
-#if !IS_ENABLED(CONFIG_SCSI_PROC_FS)
-static int
-sg_proc_init(void)
-{
- return 0;
-}
-#endif
-
static void __exit
exit_sg(void)
{
+ sg_dfs_exit();
if (IS_ENABLED(CONFIG_SCSI_PROC_FS))
remove_proc_subtree("scsi/sg", NULL);
scsi_unregister_interface(&sg_interface);
@@ -3255,7 +3240,7 @@ sg_find_srp_by_id(struct sg_fd *sfp, int pack_id)
/* here if one of above loops does _not_ find a match */
if (IS_ENABLED(CONFIG_SCSI_PROC_FS)) {
if (search_for_1) {
- const char *cptp = "pack_id=";
+ __maybe_unused const char *cptp = "pack_id=";
if (is_bad_st)
SG_LOG(1, sfp, "%s: %s%d wrong state: %s\n",
@@ -3692,17 +3677,6 @@ sg_remove_sfp(struct kref *kref)
schedule_work(&sfp->ew_fd.work);
}
-static int
-sg_idr_max_id(int id, void *p, void *data)
- __must_hold(sg_index_lock)
-{
- int *k = data;
-
- if (*k < id)
- *k = id;
- return 0;
-}
-
/* must be called with sg_index_lock held */
static struct sg_device *
sg_lookup_dev(int dev)
@@ -3732,7 +3706,7 @@ sg_get_dev(int dev)
return sdp;
}
-#if IS_ENABLED(CONFIG_SCSI_PROC_FS)
+#if IS_ENABLED(SG_PROC_OR_DEBUG_FS)
static const char *
sg_rq_st_str(enum sg_rq_state rq_st, bool long_str)
{
@@ -3761,7 +3735,35 @@ sg_rq_st_str(enum sg_rq_state rq_st, bool long_str)
}
#endif
-#if IS_ENABLED(CONFIG_SCSI_PROC_FS) /* long, almost to end of file */
+#if IS_ENABLED(SG_PROC_OR_DEBUG_FS)
+
+#define SG_SNAPSHOT_DEV_MAX 4
+
+/*
+ * For snapshot_devs array, -1 or two adjacent the same is terminator.
+ * -1 in first element of first two elements the same implies all.
+ */
+static struct sg_dfs_context_t {
+ struct dentry *dfs_rootdir;
+ int snapshot_devs[SG_SNAPSHOT_DEV_MAX];
+} sg_dfs_cxt;
+
+struct sg_proc_deviter {
+ loff_t index;
+ size_t max;
+ int fd_index;
+};
+
+static int
+sg_idr_max_id(int id, void *p, void *data)
+ __must_hold(sg_index_lock)
+{
+ int *k = data;
+
+ if (*k < id)
+ *k = id;
+ return 0;
+}
static int
sg_last_dev(void)
@@ -3775,6 +3777,41 @@ sg_last_dev(void)
return k + 1; /* origin 1 */
}
+static void *
+dev_seq_start(struct seq_file *s, loff_t *pos)
+{
+ struct sg_proc_deviter *it = kzalloc(sizeof(*it), GFP_KERNEL);
+
+ s->private = it;
+ if (!it)
+ return NULL;
+
+ it->index = *pos;
+ it->max = sg_last_dev();
+ if (it->index >= it->max)
+ return NULL;
+ return it;
+}
+
+static void *
+dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ struct sg_proc_deviter *it = s->private;
+
+ *pos = ++it->index;
+ return (it->index < it->max) ? it : NULL;
+}
+
+static void
+dev_seq_stop(struct seq_file *s, void *v)
+{
+ kfree(s->private);
+}
+
+#endif /* SG_PROC_OR_DEBUG_FS */
+
+#if IS_ENABLED(CONFIG_SCSI_PROC_FS) /* around 100 lines */
+
static int
sg_proc_seq_show_int(struct seq_file *s, void *v)
{
@@ -3788,7 +3825,7 @@ sg_proc_single_open_adio(struct inode *inode, struct file *filp)
return single_open(filp, sg_proc_seq_show_int, &sg_allow_dio);
}
-static ssize_t
+static ssize_t
sg_proc_write_adio(struct file *filp, const char __user *buffer,
size_t count, loff_t *off)
{
@@ -3810,7 +3847,7 @@ sg_proc_single_open_dressz(struct inode *inode, struct file *filp)
return single_open(filp, sg_proc_seq_show_int, &sg_big_buff);
}
-static ssize_t
+static ssize_t
sg_proc_write_dressz(struct file *filp, const char __user *buffer,
size_t count, loff_t *off)
{
@@ -3845,43 +3882,6 @@ sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
return 0;
}
-struct sg_proc_deviter {
- loff_t index;
- size_t max;
- int fd_index;
-};
-
-static void *
-dev_seq_start(struct seq_file *s, loff_t *pos)
-{
- struct sg_proc_deviter *it = kzalloc(sizeof(*it), GFP_KERNEL);
-
- s->private = it;
- if (! it)
- return NULL;
-
- it->index = *pos;
- it->max = sg_last_dev();
- if (it->index >= it->max)
- return NULL;
- return it;
-}
-
-static void *
-dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
-{
- struct sg_proc_deviter *it = s->private;
-
- *pos = ++it->index;
- return (it->index < it->max) ? it : NULL;
-}
-
-static void
-dev_seq_stop(struct seq_file *s, void *v)
-{
- kfree(s->private);
-}
-
static int
sg_proc_seq_show_dev(struct seq_file *s, void *v)
{
@@ -3928,6 +3928,10 @@ sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
return 0;
}
+#endif /* CONFIG_SCSI_PROC_FS (~100 lines back) */
+
+#if IS_ENABLED(SG_PROC_OR_DEBUG_FS)
+
/* Writes debug info for one sg_request in obp buffer */
static int
sg_proc_debug_sreq(struct sg_request *srp, int to, char *obp, int len)
@@ -4070,18 +4074,20 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
bool found = false;
bool trunc = false;
const int bp_len = SG_PROC_DEBUG_SZ;
+ int j, sd_n;
int n = 0;
int k = 0;
unsigned long iflags;
struct sg_proc_deviter *it = (struct sg_proc_deviter *)v;
struct sg_device *sdp;
int *fdi_p;
+ const int *dev_arr = sg_dfs_cxt.snapshot_devs;
char *bp;
char *disk_name;
char b1[128];
b1[0] = '\0';
- if (it && (0 == it->index))
+ if (it && it->index == 0)
seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
(int)it->max, def_reserved_size);
fdi_p = it ? &it->fd_index : &k;
@@ -4093,8 +4099,31 @@ 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 (NULL == sdp)
+ if (!sdp)
goto skip;
+ sd_n = dev_arr[0];
+ if (sd_n != -1 && sd_n != sdp->index && sd_n != dev_arr[1]) {
+ for (j = 1; j < SG_SNAPSHOT_DEV_MAX; ) {
+ sd_n = dev_arr[j];
+ if (sd_n < 0)
+ goto skip;
+ ++j;
+ if (j >= SG_SNAPSHOT_DEV_MAX) {
+ if (sd_n == sdp->index) {
+ found = true;
+ break;
+ }
+ } else if (sd_n == dev_arr[j]) {
+ goto skip;
+ } else if (sd_n == sdp->index) {
+ found = true;
+ break;
+ }
+ }
+ if (!found)
+ goto skip;
+ found = false;
+ }
if (!xa_empty(&sdp->sfp_arr)) {
found = true;
disk_name = (sdp->disk ? sdp->disk->disk_name : "?_?");
@@ -4134,6 +4163,10 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
return 0;
}
+#endif /* SG_PROC_OR_DEBUG_FS */
+
+#if IS_ENABLED(CONFIG_SCSI_PROC_FS)
+
static const struct proc_ops adio_proc_ops = {
.proc_open = sg_proc_single_open_adio,
.proc_read = seq_read,
@@ -4192,7 +4225,226 @@ sg_proc_init(void)
/* remove_proc_subtree("scsi/sg", NULL) in exit_sg() does cleanup */
-#endif /* CONFIG_SCSI_PROC_FS (~400 lines back) */
+#else
+
+static int
+sg_proc_init(void)
+{
+ return 0;
+}
+
+#endif /* CONFIG_SCSI_PROC_FS */
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+
+struct sg_dfs_attr {
+ const char *name;
+ umode_t mode;
+ int (*show)(void *d, struct seq_file *m);
+ ssize_t (*write)(void *d, const char __user *b, size_t s, loff_t *o);
+ /* Set either .show or .seq_ops. */
+ const struct seq_operations *seq_ops;
+};
+static int
+sg_dfs_snapshot_devs_show(void *data, struct seq_file *m)
+{
+ bool last;
+ int k, d;
+ struct sg_dfs_context_t *ctxp = data;
+
+ for (k = 0; k < SG_SNAPSHOT_DEV_MAX; ++k) {
+ d = ctxp->snapshot_devs[k];
+ last = (k + 1 == SG_SNAPSHOT_DEV_MAX);
+ if (d < 0) {
+ if (k == 0)
+ seq_puts(m, "-1");
+ break;
+ }
+ if (!last && d == ctxp->snapshot_devs[k + 1]) {
+ if (k == 0)
+ seq_puts(m, "-1");
+ break;
+ }
+ if (k != 0)
+ seq_puts(m, ",");
+ seq_printf(m, "%d", d);
+ }
+ seq_puts(m, "\n");
+ return 0;
+}
+
+static ssize_t
+sg_dfs_snapshot_devs_write(void *data, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ bool trailing_comma;
+ int k, n;
+ struct sg_dfs_context_t *cxtp = data;
+ char lbuf[64] = { }, *cp, *c2p;
+
+ if (count >= sizeof(lbuf)) {
+ pr_err("%s: operation too long\n", __func__);
+ return -EINVAL;
+ }
+ if (copy_from_user(lbuf, buf, count))
+ return -EFAULT;
+ for (k = 0, n = 0, cp = lbuf; k < SG_SNAPSHOT_DEV_MAX;
+ ++k, cp = c2p + 1) {
+ c2p = strchr(cp, ',');
+ if (c2p)
+ *c2p = '\0';
+ trailing_comma = !!c2p;
+ /* sscanf is easier to use that this ... */
+ if (kstrtoint(cp, 10, cxtp->snapshot_devs + k))
+ break;
+ ++n;
+ if (!trailing_comma)
+ break;
+ }
+ if (n == 0) {
+ return -EINVAL;
+ } else if (k >= SG_SNAPSHOT_DEV_MAX && trailing_comma) {
+ pr_err("%s: only %d elements in snapshot array\n", __func__,
+ SG_SNAPSHOT_DEV_MAX);
+ return -EINVAL;
+ }
+ if (n < SG_SNAPSHOT_DEV_MAX)
+ cxtp->snapshot_devs[n] = -1;
+ return count;
+}
+
+static int
+sg_dfs_show(struct seq_file *m, void *v)
+{
+ const struct sg_dfs_attr *attr = m->private;
+ void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
+
+ return attr->show(data, m);
+}
+
+static ssize_t
+sg_dfs_write(struct file *file, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct seq_file *m = file->private_data;
+ const struct sg_dfs_attr *attr = m->private;
+ void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
+
+ /*
+ * Attributes that only implement .seq_ops are read-only and 'attr' is
+ * the same with 'data' in this case.
+ */
+ if (attr == data || !attr->write)
+ return -EPERM;
+ return attr->write(data, buf, count, ppos);
+}
+
+static int
+sg_dfs_open(struct inode *inode, struct file *file)
+{
+ const struct sg_dfs_attr *attr = inode->i_private;
+ void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
+ struct seq_file *m;
+ int ret;
+
+ if (attr->seq_ops) {
+ ret = seq_open(file, attr->seq_ops);
+ if (!ret) {
+ m = file->private_data;
+ m->private = data;
+ }
+ return ret;
+ }
+ if (WARN_ON_ONCE(!attr->show))
+ return -EPERM;
+ return single_open(file, sg_dfs_show, inode->i_private);
+}
+
+static int
+sg_dfs_release(struct inode *inode, struct file *file)
+{
+ const struct sg_dfs_attr *attr = inode->i_private;
+
+ if (attr->show)
+ return single_release(inode, file);
+ return seq_release(inode, file);
+}
+
+static const struct file_operations sg_dfs_fops = {
+ .owner = THIS_MODULE,
+ .open = sg_dfs_open,
+ .read = seq_read,
+ .write = sg_dfs_write,
+ .llseek = seq_lseek,
+ .release = sg_dfs_release,
+};
+
+static void sg_dfs_mk_files(struct dentry *parent, void *data,
+ const struct sg_dfs_attr *attr)
+{
+ if (IS_ERR_OR_NULL(parent))
+ return;
+
+ d_inode(parent)->i_private = data;
+ for (; attr->name; ++attr)
+ debugfs_create_file(attr->name, attr->mode, parent,
+ (void *)attr, &sg_dfs_fops);
+}
+
+static const struct seq_operations sg_snapshot_seq_ops = {
+ .start = dev_seq_start,
+ .next = dev_seq_next,
+ .stop = dev_seq_stop,
+ .show = sg_proc_seq_show_debug,
+};
+
+static const struct sg_dfs_attr sg_dfs_attrs[] = {
+ {"snapshot", 0400, .seq_ops = &sg_snapshot_seq_ops},
+ {"snapshot_devs", 0600, sg_dfs_snapshot_devs_show,
+ sg_dfs_snapshot_devs_write},
+ { },
+};
+
+static void
+sg_dfs_init(void)
+{
+ /* create and populate /sys/kernel/debug/scsi_generic directory */
+ if (!sg_dfs_cxt.dfs_rootdir) {
+ sg_dfs_cxt.dfs_rootdir = debugfs_create_dir("scsi_generic",
+ NULL);
+ sg_dfs_mk_files(sg_dfs_cxt.dfs_rootdir, &sg_dfs_cxt,
+ sg_dfs_attrs);
+ }
+ sg_dfs_cxt.snapshot_devs[0] = -1; /* show all sg devices */
+}
+
+static void
+sg_dfs_exit(void)
+{
+ debugfs_remove_recursive(sg_dfs_cxt.dfs_rootdir);
+ sg_dfs_cxt.dfs_rootdir = NULL;
+}
+
+#else /* not defined: CONFIG_DEBUG_FS */
+
+static void sg_dfs_init(void) {}
+static void sg_dfs_exit(void) {}
+
+#endif /* CONFIG_DEBUG_FS */
+
+module_param_named(scatter_elem_sz, scatter_elem_sz, int, 0644);
+module_param_named(def_reserved_size, def_reserved_size, int, 0644);
+module_param_named(allow_dio, sg_allow_dio, int, 0644);
+
+MODULE_AUTHOR("Douglas Gilbert");
+MODULE_DESCRIPTION("SCSI generic (sg) driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(SG_VERSION_STR);
+MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
+
+MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
+MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
+MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
module_init(init_sg);
module_exit(exit_sg);