From 897a316c9e6f7fea6f1d3759797b75c0ebaec479 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Tue, 18 Dec 2007 18:23:39 +0200 Subject: [PATCH] UBI: handle attach ioctl Actually implement the MTD device attach/detach handlers. Signed-off-by: Artem Bityutskiy --- drivers/mtd/ubi/build.c | 80 +++++++++++++++++++++++----------- drivers/mtd/ubi/cdev.c | 95 ++++++++++++++++++++++++++++++++++------- drivers/mtd/ubi/ubi.h | 2 +- 3 files changed, 135 insertions(+), 42 deletions(-) diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 403c10a668..70c0b9a9e6 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -621,18 +621,19 @@ static int io_init(struct ubi_device *ubi) /** * ubi_attach_mtd_dev - attach an MTD device. * @mtd_dev: MTD device description object + * @ubi_num: number to assign to the new UBI device * @vid_hdr_offset: VID header offset * - * This function attaches an MTD device to UBI. It first treats @mtd_dev as the - * MTD device name, and tries to open it by this name. If it is unable to open, - * it tries to convert @mtd_dev to an integer and open the MTD device by its - * number. Returns new UBI device's number in case of success and a negative - * error code in case of failure. + * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number + * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in + * which case this function finds a vacant device nubert and assings it + * automatically. Returns the new UBI device number in case of success and a + * negative error code in case of failure. * * Note, the invocations of this function has to be serialized by the * @ubi_devices_mutex. */ -int ubi_attach_mtd_dev(struct mtd_info *mtd, int vid_hdr_offset) +int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset) { struct ubi_device *ubi; int i, err; @@ -643,22 +644,47 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int vid_hdr_offset) * Note, this function assumes that UBI devices creations and deletions * are serialized, so it does not take the &ubi_devices_lock. */ - for (i = 0; i < UBI_MAX_DEVICES; i++) + for (i = 0; i < UBI_MAX_DEVICES; i++) { ubi = ubi_devices[i]; if (ubi && mtd->index == ubi->mtd->index) { - ubi_err("mtd%d is already attached to ubi%d", + dbg_err("mtd%d is already attached to ubi%d", mtd->index, i); - return -EINVAL; + return -EEXIST; } + } - /* Search for an empty slot in the @ubi_devices array */ - for (i = 0; i < UBI_MAX_DEVICES; i++) - if (!ubi_devices[i]) - break; + /* + * Make sure this MTD device is not emulated on top of an UBI volume + * already. Well, generally this recursion works fine, but there are + * different problems like the UBI module takes a reference to itself + * by attaching (and thus, opening) the emulated MTD device. This + * results in inability to unload the module. And in general it makes + * no sense to attach emulated MTD devices, so we prohibit this. + */ + if (mtd->type == MTD_UBIVOLUME) { + ubi_err("refuse attaching mtd%d - it is already emulated on " + "top of UBI", mtd->index); + return -EINVAL; + } + + if (ubi_num == UBI_DEV_NUM_AUTO) { + /* Search for an empty slot in the @ubi_devices array */ + for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++) + if (!ubi_devices[ubi_num]) + break; + if (ubi_num == UBI_MAX_DEVICES) { + dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES); + return -ENFILE; + } + } else { + if (ubi_num >= UBI_MAX_DEVICES) + return -EINVAL; - if (i == UBI_MAX_DEVICES) { - ubi_err("only %d UBI devices may be created", UBI_MAX_DEVICES); - return -ENFILE; + /* Make sure ubi_num is not busy */ + if (ubi_devices[ubi_num]) { + dbg_err("ubi%d already exists", ubi_num); + return -EEXIST; + } } ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL); @@ -666,11 +692,11 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int vid_hdr_offset) return -ENOMEM; ubi->mtd = mtd; - ubi->ubi_num = i; + ubi->ubi_num = ubi_num; ubi->vid_hdr_offset = vid_hdr_offset; dbg_msg("attaching mtd%d to ubi%d: VID header offset %d", - mtd->index, ubi->ubi_num, vid_hdr_offset); + mtd->index, ubi_num, vid_hdr_offset); err = io_init(ubi); if (err) @@ -710,7 +736,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int vid_hdr_offset) goto out_uif; } - ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi->ubi_num); + ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num); ubi_msg("MTD device name: \"%s\"", mtd->name); ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20); ubi_msg("physical eraseblock size: %d bytes (%d KiB)", @@ -739,8 +765,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int vid_hdr_offset) wake_up_process(ubi->bgt_thread); } - ubi_devices[ubi->ubi_num] = ubi; - return ubi->ubi_num; + ubi_devices[ubi_num] = ubi; + return ubi_num; out_uif: uif_close(ubi); @@ -781,23 +807,24 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway) spin_lock(&ubi_devices_lock); ubi = ubi_devices[ubi_num]; if (!ubi) { - spin_lock(&ubi_devices_lock); + spin_unlock(&ubi_devices_lock); return -EINVAL; } if (ubi->ref_count) { if (!anyway) { - spin_lock(&ubi_devices_lock); + spin_unlock(&ubi_devices_lock); return -EBUSY; } /* This may only happen if there is a bug */ ubi_err("%s reference count %d, destroy anyway", ubi->ubi_name, ubi->ref_count); } - ubi_devices[ubi->ubi_num] = NULL; + ubi_devices[ubi_num] = NULL; spin_unlock(&ubi_devices_lock); - dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi->ubi_num); + ubi_assert(ubi_num == ubi->ubi_num); + dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num); /* * Before freeing anything, we have to stop the background thread to @@ -935,7 +962,8 @@ static int __init ubi_init(void) } mutex_lock(&ubi_devices_mutex); - err = ubi_attach_mtd_dev(mtd, p->vid_hdr_offs); + err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, + p->vid_hdr_offs); mutex_unlock(&ubi_devices_mutex); if (err < 0) { put_mtd_device(mtd); diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index 01978b57e9..a60a3a24c2 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -44,17 +44,6 @@ #include #include "ubi.h" -/* - * Maximum sequence numbers of UBI and volume character device IOCTLs (direct - * logical eraseblock erase is a debug-only feature). - */ -#define UBI_CDEV_IOC_MAX_SEQ 2 -#ifndef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO -#define VOL_CDEV_IOC_MAX_SEQ 1 -#else -#define VOL_CDEV_IOC_MAX_SEQ 2 -#endif - /** * get_exclusive - get exclusive access to an UBI volume. * @desc: volume descriptor @@ -582,8 +571,7 @@ static int ubi_cdev_ioctl(struct inode *inode, struct file *file, struct ubi_mkvol_req req; dbg_msg("create volume"); - err = copy_from_user(&req, argp, - sizeof(struct ubi_mkvol_req)); + err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req)); if (err) { err = -EFAULT; break; @@ -647,8 +635,7 @@ static int ubi_cdev_ioctl(struct inode *inode, struct file *file, struct ubi_rsvol_req req; dbg_msg("re-size volume"); - err = copy_from_user(&req, argp, - sizeof(struct ubi_rsvol_req)); + err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req)); if (err) { err = -EFAULT; break; @@ -684,8 +671,86 @@ static int ubi_cdev_ioctl(struct inode *inode, struct file *file, return err; } +static int ctrl_cdev_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int err = 0; + void __user *argp = (void __user *)arg; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + switch (cmd) { + /* Attach an MTD device command */ + case UBI_IOCATT: + { + struct ubi_attach_req req; + struct mtd_info *mtd; + + dbg_msg("attach MTD device"); + err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req)); + if (err) { + err = -EFAULT; + break; + } + + if (req.mtd_num < 0 || + (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) { + err = -EINVAL; + break; + } + + mtd = get_mtd_device(NULL, req.mtd_num); + if (IS_ERR(mtd)) { + err = PTR_ERR(mtd); + break; + } + + /* + * Note, further request verification is done by + * 'ubi_attach_mtd_dev()'. + */ + mutex_lock(&ubi_devices_mutex); + err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset); + mutex_unlock(&ubi_devices_mutex); + if (err < 0) + put_mtd_device(mtd); + else + /* @err contains UBI device number */ + err = put_user(err, (__user int32_t *)argp); + + break; + } + + /* Detach an MTD device command */ + case UBI_IOCDET: + { + int ubi_num; + + dbg_msg("dettach MTD device"); + err = get_user(ubi_num, (__user int32_t *)argp); + if (err) { + err = -EFAULT; + break; + } + + mutex_lock(&ubi_devices_mutex); + err = ubi_detach_mtd_dev(ubi_num, 0); + mutex_unlock(&ubi_devices_mutex); + break; + } + + default: + err = -ENOTTY; + break; + } + + return err; +} + /* UBI control character device operations */ struct file_operations ubi_ctrl_cdev_operations = { + .ioctl = ctrl_cdev_ioctl, .owner = THIS_MODULE, }; diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 4c3607e574..2a6171226f 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -483,7 +483,7 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum, struct ubi_vid_hdr *vid_hdr); /* build.c */ -int ubi_attach_mtd_dev(struct mtd_info *mtd, int vid_hdr_offset); +int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset); int ubi_detach_mtd_dev(int ubi_num, int anyway); struct ubi_device *ubi_get_device(int ubi_num); void ubi_put_device(struct ubi_device *ubi); -- 2.39.5