From: Sidney Amani Date: Tue, 27 Jan 2009 09:11:46 +0000 (+0100) Subject: UBI: allow direct user-space I/O X-Git-Tag: v2.6.29-rc4~102^2 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=766fb95ba06e1bbf531d30dc05e21b2d4a0e8dd2 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: Sidney Amani Signed-off-by: Corentin Chary Signed-off-by: Artem Bityutskiy --- diff --git a/drivers/mtd/ubi/Kconfig.debug b/drivers/mtd/ubi/Kconfig.debug index 1e2ee22..2246f15 100644 --- a/drivers/mtd/ubi/Kconfig.debug +++ b/drivers/mtd/ubi/Kconfig.debug @@ -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 diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index f9631eb..e63c8fc 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -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; diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 381f0e1..c055511 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -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 diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index 82113e1..296efae 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -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__ */