Commit 766fb95b authored by Sidney Amani's avatar Sidney Amani Committed by Artem Bityutskiy

UBI: allow direct user-space I/O

Introduce a new ioctl UBI_IOCSETPROP to set properties
on a volume. Also add the first property:
UBI_PROP_DIRECT_WRITE, this property is used to set the
ability to use direct writes in userspace
Signed-off-by: default avatarSidney Amani <seed@uffs.org>
Signed-off-by: default avatarCorentin Chary <corentincj@iksaif.net>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 36b477d0
......@@ -33,16 +33,6 @@ config MTD_UBI_DEBUG_DISABLE_BGT
This option switches the background thread off by default. The thread
may be also be enabled/disabled via UBI sysfs.
config MTD_UBI_DEBUG_USERSPACE_IO
bool "Direct user-space write/erase support"
default n
depends on MTD_UBI_DEBUG
help
By default, users cannot directly write and erase individual
eraseblocks of dynamic volumes, and have to use update operation
instead. This option enables this capability - it is very useful for
debugging and testing.
config MTD_UBI_DEBUG_EMULATE_BITFLIPS
bool "Emulate flash bit-flips"
depends on MTD_UBI_DEBUG
......
......@@ -259,12 +259,9 @@ static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
return err ? err : count_save - count;
}
#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
/*
* This function allows to directly write to dynamic UBI volumes, without
* issuing the volume update operation. Available only as a debugging feature.
* Very useful for testing UBI.
* issuing the volume update operation.
*/
static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
......@@ -276,6 +273,9 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
size_t count_save = count;
char *tbuf;
if (!vol->direct_writes)
return -EPERM;
dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
count, *offp, vol->vol_id);
......@@ -339,10 +339,6 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
return err ? err : count_save - count;
}
#else
#define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
#endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
{
......@@ -552,6 +548,30 @@ static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
break;
}
/* Set volume property command*/
case UBI_IOCSETPROP:
{
struct ubi_set_prop_req req;
err = copy_from_user(&req, argp,
sizeof(struct ubi_set_prop_req));
if (err) {
err = -EFAULT;
break;
}
switch (req.property) {
case UBI_PROP_DIRECT_WRITE:
mutex_lock(&ubi->volumes_mutex);
desc->vol->direct_writes = !!req.value;
mutex_unlock(&ubi->volumes_mutex);
break;
default:
err = -EINVAL;
break;
}
break;
}
default:
err = -ENOTTY;
break;
......
......@@ -206,6 +206,7 @@ struct ubi_volume_desc;
* @upd_marker: %1 if the update marker is set for this volume
* @updating: %1 if the volume is being updated
* @changing_leb: %1 if the atomic LEB change ioctl command is in progress
* @direct_writes: %1 if direct writes are enabled for this volume
*
* @gluebi_desc: gluebi UBI volume descriptor
* @gluebi_refcount: reference count of the gluebi MTD device
......@@ -253,6 +254,7 @@ struct ubi_volume {
unsigned int upd_marker:1;
unsigned int updating:1;
unsigned int changing_leb:1;
unsigned int direct_writes:1;
#ifdef CONFIG_MTD_UBI_GLUEBI
/*
......@@ -304,7 +306,8 @@ struct ubi_wl_entry;
* @vtbl_size: size of the volume table in bytes
* @vtbl: in-RAM volume table copy
* @volumes_mutex: protects on-flash volume table and serializes volume
* changes, like creation, deletion, update, re-size and re-name
* changes, like creation, deletion, update, re-size,
* re-name and set property
*
* @max_ec: current highest erase counter value
* @mean_ec: current mean erase counter value
......
......@@ -124,6 +124,14 @@
* To check if a logical eraseblock is mapped to a physical eraseblock, the
* %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is
* not mapped, and %1 if it is mapped.
*
* Set an UBI volume property
* ~~~~~~~~~~~~~~~~~~~~~~~~~
*
* To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be
* used. A pointer to a &struct ubi_set_prop_req object is expected to be
* passed. The object describes which property should be set, and to which value
* it should be set.
*/
/*
......@@ -175,6 +183,8 @@
#define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, int32_t)
/* Check if LEB is mapped command */
#define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, int32_t)
/* Set an UBI volume property */
#define UBI_IOCSETPROP _IOW(UBI_VOL_IOC_MAGIC, 6, struct ubi_set_prop_req)
/* Maximum MTD device name length supported by UBI */
#define MAX_UBI_MTD_NAME_LEN 127
......@@ -210,6 +220,16 @@ enum {
UBI_STATIC_VOLUME = 4,
};
/*
* UBI set property ioctl constants
*
* @UBI_PROP_DIRECT_WRITE: allow / disallow user to directly write and
* erase individual eraseblocks on dynamic volumes
*/
enum {
UBI_PROP_DIRECT_WRITE = 1,
};
/**
* struct ubi_attach_req - attach MTD device request.
* @ubi_num: UBI device number to create
......@@ -373,4 +393,18 @@ struct ubi_map_req {
int8_t padding[3];
} __attribute__ ((packed));
/**
* struct ubi_set_prop_req - a data structure used to set an ubi volume
* property.
* @property: property to set (%UBI_PROP_DIRECT_WRITE)
* @padding: reserved for future, not used, has to be zeroed
* @value: value to set
*/
struct ubi_set_prop_req {
uint8_t property;
uint8_t padding[7];
uint64_t value;
} __attribute__ ((packed));
#endif /* __UBI_USER_H__ */
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