diff options
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/ubi/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/mtd/ubi/Makefile | 2 | ||||
| -rw-r--r-- | drivers/mtd/ubi/gluebi.c | 378 |
3 files changed, 295 insertions, 98 deletions
diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig index 3f063108e95f..b1cd7a1a2191 100644 --- a/drivers/mtd/ubi/Kconfig +++ b/drivers/mtd/ubi/Kconfig @@ -49,15 +49,16 @@ config MTD_UBI_BEB_RESERVE reserved. Leave the default value if unsure. config MTD_UBI_GLUEBI - bool "Emulate MTD devices" + tristate "MTD devices emulation driver (gluebi)" default n depends on MTD_UBI help - This option enables MTD devices emulation on top of UBI volumes: for - each UBI volumes an MTD device is created, and all I/O to this MTD - device is redirected to the UBI volume. This is handy to make - MTD-oriented software (like JFFS2) work on top of UBI. Do not enable - this if no legacy software will be used. + This option enables gluebi - an additional driver which emulates MTD + devices on top of UBI volumes: for each UBI volumes an MTD device is + created, and all I/O to this MTD device is redirected to the UBI + volume. This is handy to make MTD-oriented software (like JFFS2) + work on top of UBI. Do not enable this unless you use legacy + software. source "drivers/mtd/ubi/Kconfig.debug" endmenu diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile index dd834e04151b..c9302a5452b0 100644 --- a/drivers/mtd/ubi/Makefile +++ b/drivers/mtd/ubi/Makefile @@ -4,4 +4,4 @@ ubi-y += vtbl.o vmt.o upd.o build.o cdev.o kapi.o eba.o io.o wl.o scan.o ubi-y += misc.o ubi-$(CONFIG_MTD_UBI_DEBUG) += debug.o -ubi-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o +obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o diff --git a/drivers/mtd/ubi/gluebi.c b/drivers/mtd/ubi/gluebi.c index 49cd55ade9c8..95aaac03f938 100644 --- a/drivers/mtd/ubi/gluebi.c +++ b/drivers/mtd/ubi/gluebi.c @@ -19,17 +19,71 @@ */ /* - * This file includes implementation of fake MTD devices for each UBI volume. - * This sounds strange, but it is in fact quite useful to make MTD-oriented - * software (including all the legacy software) to work on top of UBI. + * This is a small driver which implements fake MTD devices on top of UBI + * volumes. This sounds strange, but it is in fact quite useful to make + * MTD-oriented software (including all the legacy software) work on top of + * UBI. * * Gluebi emulates MTD devices of "MTD_UBIVOLUME" type. Their minimal I/O unit - * size (mtd->writesize) is equivalent to the UBI minimal I/O unit. The + * size (@mtd->writesize) is equivalent to the UBI minimal I/O unit. The * eraseblock size is equivalent to the logical eraseblock size of the volume. */ +#include <linux/err.h> +#include <linux/list.h> +#include <linux/sched.h> #include <linux/math64.h> -#include "ubi.h" +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/mtd/ubi.h> +#include <linux/mtd/mtd.h> +#include "ubi-media.h" + +#define err_msg(fmt, ...) \ + printk(KERN_DEBUG "gluebi (pid %d): %s: " fmt "\n", \ + current->pid, __func__, ##__VA_ARGS__) + +/** + * struct gluebi_device - a gluebi device description data structure. + * @mtd: emulated MTD device description object + * @refcnt: gluebi device reference count + * @desc: UBI volume descriptor + * @ubi_num: UBI device number this gluebi device works on + * @vol_id: ID of UBI volume this gluebi device works on + * @list: link in a list of gluebi devices + */ +struct gluebi_device { + struct mtd_info mtd; + int refcnt; + struct ubi_volume_desc *desc; + int ubi_num; + int vol_id; + struct list_head list; +}; + +/* List of all gluebi devices */ +static LIST_HEAD(gluebi_devices); +static DEFINE_MUTEX(devices_mutex); + +/** + * find_gluebi_nolock - find a gluebi device. + * @ubi_num: UBI device number + * @vol_id: volume ID + * + * This function seraches for gluebi device corresponding to UBI device + * @ubi_num and UBI volume @vol_id. Returns the gluebi device description + * object in case of success and %NULL in case of failure. The caller has to + * have the &devices_mutex locked. + */ +static struct gluebi_device *find_gluebi_nolock(int ubi_num, int vol_id) +{ + struct gluebi_device *gluebi; + + list_for_each_entry(gluebi, &gluebi_devices, list) + if (gluebi->ubi_num == ubi_num && gluebi->vol_id == vol_id) + return gluebi; + return NULL; +} /** * gluebi_get_device - get MTD device reference. @@ -41,15 +95,18 @@ */ static int gluebi_get_device(struct mtd_info *mtd) { - struct ubi_volume *vol; + struct gluebi_device *gluebi; + int ubi_mode = UBI_READONLY; - vol = container_of(mtd, struct ubi_volume, gluebi_mtd); + if (!try_module_get(THIS_MODULE)) + return -ENODEV; - /* - * We do not introduce locks for gluebi reference count because the - * get_device()/put_device() calls are already serialized at MTD. - */ - if (vol->gluebi_refcount > 0) { + if (mtd->flags & MTD_WRITEABLE) + ubi_mode = UBI_READWRITE; + + gluebi = container_of(mtd, struct gluebi_device, mtd); + mutex_lock(&devices_mutex); + if (gluebi->refcnt > 0) { /* * The MTD device is already referenced and this is just one * more reference. MTD allows many users to open the same @@ -58,7 +115,8 @@ static int gluebi_get_device(struct mtd_info *mtd) * open the UBI volume again - just increase the reference * counter and return. */ - vol->gluebi_refcount += 1; + gluebi->refcnt += 1; + mutex_unlock(&devices_mutex); return 0; } @@ -66,11 +124,15 @@ static int gluebi_get_device(struct mtd_info *mtd) * This is the first reference to this UBI volume via the MTD device * interface. Open the corresponding volume in read-write mode. */ - vol->gluebi_desc = ubi_open_volume(vol->ubi->ubi_num, vol->vol_id, - UBI_READWRITE); - if (IS_ERR(vol->gluebi_desc)) - return PTR_ERR(vol->gluebi_desc); - vol->gluebi_refcount += 1; + gluebi->desc = ubi_open_volume(gluebi->ubi_num, gluebi->vol_id, + ubi_mode); + if (IS_ERR(gluebi->desc)) { + mutex_unlock(&devices_mutex); + module_put(THIS_MODULE); + return PTR_ERR(gluebi->desc); + } + gluebi->refcnt += 1; + mutex_unlock(&devices_mutex); return 0; } @@ -83,13 +145,15 @@ static int gluebi_get_device(struct mtd_info *mtd) */ static void gluebi_put_device(struct mtd_info *mtd) { - struct ubi_volume *vol; - - vol = container_of(mtd, struct ubi_volume, gluebi_mtd); - vol->gluebi_refcount -= 1; - ubi_assert(vol->gluebi_refcount >= 0); - if (vol->gluebi_refcount == 0) - ubi_close_volume(vol->gluebi_desc); + struct gluebi_device *gluebi; + + gluebi = container_of(mtd, struct gluebi_device, mtd); + mutex_lock(&devices_mutex); + gluebi->refcnt -= 1; + if (gluebi->refcnt == 0) + ubi_close_volume(gluebi->desc); + module_put(THIS_MODULE); + mutex_unlock(&devices_mutex); } /** @@ -107,16 +171,12 @@ static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, unsigned char *buf) { int err = 0, lnum, offs, total_read; - struct ubi_volume *vol; - struct ubi_device *ubi; - - dbg_gen("read %zd bytes from offset %lld", len, from); + struct gluebi_device *gluebi; if (len < 0 || from < 0 || from + len > mtd->size) return -EINVAL; - vol = container_of(mtd, struct ubi_volume, gluebi_mtd); - ubi = vol->ubi; + gluebi = container_of(mtd, struct gluebi_device, mtd); lnum = div_u64_rem(from, mtd->erasesize, &offs); total_read = len; @@ -126,7 +186,7 @@ static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len, if (to_read > total_read) to_read = total_read; - err = ubi_eba_read_leb(ubi, vol, lnum, buf, offs, to_read, 0); + err = ubi_read(gluebi->desc, lnum, buf, offs, to_read); if (err) break; @@ -152,21 +212,17 @@ static int gluebi_read(struct mtd_info *mtd, loff_t from, size_t len, * case of failure. */ static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len, - size_t *retlen, const u_char *buf) + size_t *retlen, const u_char *buf) { int err = 0, lnum, offs, total_written; - struct ubi_volume *vol; - struct ubi_device *ubi; - - dbg_gen("write %zd bytes to offset %lld", len, to); + struct gluebi_device *gluebi; if (len < 0 || to < 0 || len + to > mtd->size) return -EINVAL; - vol = container_of(mtd, struct ubi_volume, gluebi_mtd); - ubi = vol->ubi; + gluebi = container_of(mtd, struct gluebi_device, mtd); - if (ubi->ro_mode) + if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; lnum = div_u64_rem(to, mtd->erasesize, &offs); @@ -181,8 +237,7 @@ static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len, if (to_write > total_written) to_write = total_written; - err = ubi_eba_write_leb(ubi, vol, lnum, buf, offs, to_write, - UBI_UNKNOWN); + err = ubi_write(gluebi->desc, lnum, buf, offs, to_write); if (err) break; @@ -207,41 +262,36 @@ static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len, static int gluebi_erase(struct mtd_info *mtd, struct erase_info *instr) { int err, i, lnum, count; - struct ubi_volume *vol; - struct ubi_device *ubi; - - dbg_gen("erase %llu bytes at offset %llu", (unsigned long long)instr->len, - (unsigned long long)instr->addr); + struct gluebi_device *gluebi; if (instr->addr < 0 || instr->addr > mtd->size - mtd->erasesize) return -EINVAL; - if (instr->len < 0 || instr->addr + instr->len > mtd->size) return -EINVAL; - if (mtd_mod_by_ws(instr->addr, mtd) || mtd_mod_by_ws(instr->len, mtd)) return -EINVAL; lnum = mtd_div_by_eb(instr->addr, mtd); count = mtd_div_by_eb(instr->len, mtd); - vol = container_of(mtd, struct ubi_volume, gluebi_mtd); - ubi = vol->ubi; + gluebi = container_of(mtd, struct gluebi_device, mtd); - if (ubi->ro_mode) + if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; - for (i = 0; i < count; i++) { - err = ubi_eba_unmap_leb(ubi, vol, lnum + i); + for (i = 0; i < count - 1; i++) { + err = ubi_leb_unmap(gluebi->desc, lnum + i); if (err) goto out_err; } - /* * MTD erase operations are synchronous, so we have to make sure the * physical eraseblock is wiped out. + * + * Thus, perform leb_erase instead of leb_unmap operation - leb_erase + * will wait for the end of operations */ - err = ubi_wl_flush(ubi); + err = ubi_leb_erase(gluebi->desc, lnum + i); if (err) goto out_err; @@ -256,28 +306,38 @@ out_err: } /** - * ubi_create_gluebi - initialize gluebi for an UBI volume. - * @ubi: UBI device description object - * @vol: volume description object + * gluebi_create - create a gluebi device for an UBI volume. + * @di: UBI device description object + * @vi: UBI volume description object * - * This function is called when an UBI volume is created in order to create + * This function is called when a new UBI volume is created in order to create * corresponding fake MTD device. Returns zero in case of success and a * negative error code in case of failure. */ -int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol) +static int gluebi_create(struct ubi_device_info *di, + struct ubi_volume_info *vi) { - struct mtd_info *mtd = &vol->gluebi_mtd; + struct gluebi_device *gluebi, *g; + struct mtd_info *mtd; - mtd->name = kmemdup(vol->name, vol->name_len + 1, GFP_KERNEL); - if (!mtd->name) + gluebi = kzalloc(sizeof(struct gluebi_device), GFP_KERNEL); + if (!gluebi) return -ENOMEM; + mtd = &gluebi->mtd; + mtd->name = kmemdup(vi->name, vi->name_len + 1, GFP_KERNEL); + if (!mtd->name) { + kfree(gluebi); + return -ENOMEM; + } + + gluebi->vol_id = vi->vol_id; mtd->type = MTD_UBIVOLUME; - if (!ubi->ro_mode) + if (!di->ro_mode) mtd->flags = MTD_WRITEABLE; - mtd->writesize = ubi->min_io_size; mtd->owner = THIS_MODULE; - mtd->erasesize = vol->usable_leb_size; + mtd->writesize = di->min_io_size; + mtd->erasesize = vi->usable_leb_size; mtd->read = gluebi_read; mtd->write = gluebi_write; mtd->erase = gluebi_erase; @@ -285,60 +345,196 @@ int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol) mtd->put_device = gluebi_put_device; /* - * In case of dynamic volume, MTD device size is just volume size. In + * In case of dynamic a volume, MTD device size is just volume size. In * case of a static volume the size is equivalent to the amount of data * bytes. */ - if (vol->vol_type == UBI_DYNAMIC_VOLUME) - mtd->size = (long long)vol->usable_leb_size * vol->reserved_pebs; + if (vi->vol_type == UBI_DYNAMIC_VOLUME) + mtd->size = (unsigned long long)vi->usable_leb_size * vi->size; else - mtd->size = vol->used_bytes; + mtd->size = vi->used_bytes; + + /* Just a sanity check - make sure this gluebi device does not exist */ + mutex_lock(&devices_mutex); + g = find_gluebi_nolock(vi->ubi_num, vi->vol_id); + if (g) + err_msg("gluebi MTD device %d form UBI device %d volume %d " + "already exists", g->mtd.index, vi->ubi_num, + vi->vol_id); + mutex_unlock(&devices_mutex); if (add_mtd_device(mtd)) { - ubi_err("cannot not add MTD device"); + err_msg("cannot add MTD device"); kfree(mtd->name); + kfree(gluebi); return -ENFILE; } - dbg_gen("added mtd%d (\"%s\"), size %llu, EB size %u", - mtd->index, mtd->name, (unsigned long long)mtd->size, mtd->erasesize); + mutex_lock(&devices_mutex); + list_add_tail(&gluebi->list, &gluebi_devices); + mutex_unlock(&devices_mutex); return 0; } /** - * ubi_destroy_gluebi - close gluebi for an UBI volume. - * @vol: volume description object + * gluebi_remove - remove a gluebi device. + * @vi: UBI volume description object * - * This function is called when an UBI volume is removed in order to remove + * This function is called when an UBI volume is removed and it removes * corresponding fake MTD device. Returns zero in case of success and a * negative error code in case of failure. */ -int ubi_destroy_gluebi(struct ubi_volume *vol) +static int gluebi_remove(struct ubi_volume_info *vi) { - int err; - struct mtd_info *mtd = &vol->gluebi_mtd; + int err = 0; + struct mtd_info *mtd; + struct gluebi_device *gluebi; + + mutex_lock(&devices_mutex); + gluebi = find_gluebi_nolock(vi->ubi_num, vi->vol_id); + if (!gluebi) { + err_msg("got remove notification for unknown UBI device %d " + "volume %d", vi->ubi_num, vi->vol_id); + err = -ENOENT; + } else if (gluebi->refcnt) + err = -EBUSY; + else + list_del(&gluebi->list); + mutex_unlock(&devices_mutex); + if (err) + return err; - dbg_gen("remove mtd%d", mtd->index); + mtd = &gluebi->mtd; err = del_mtd_device(mtd); - if (err) + if (err) { + err_msg("cannot remove fake MTD device %d, UBI device %d, " + "volume %d, error %d", mtd->index, gluebi->ubi_num, + gluebi->vol_id, err); + mutex_lock(&devices_mutex); + list_add_tail(&gluebi->list, &gluebi_devices); + mutex_unlock(&devices_mutex); return err; + } + kfree(mtd->name); + kfree(gluebi); return 0; } /** - * ubi_gluebi_updated - UBI volume was updated notifier. - * @vol: volume description object + * gluebi_updated - UBI volume was updated notifier. + * @vi: volume info structure * - * This function is called every time an UBI volume is updated. This function - * does nothing if volume @vol is dynamic, and changes MTD device size if the + * This function is called every time an UBI volume is updated. It does nothing + * if te volume @vol is dynamic, and changes MTD device size if the * volume is static. This is needed because static volumes cannot be read past - * data they contain. + * data they contain. This function returns zero in case of success and a + * negative error code in case of error. + */ +static int gluebi_updated(struct ubi_volume_info *vi) +{ + struct gluebi_device *gluebi; + + mutex_lock(&devices_mutex); + gluebi = find_gluebi_nolock(vi->ubi_num, vi->vol_id); + if (!gluebi) { + mutex_unlock(&devices_mutex); + err_msg("got update notification for unknown UBI device %d " + "volume %d", vi->ubi_num, vi->vol_id); + return -ENOENT; + } + + if (vi->vol_type == UBI_STATIC_VOLUME) + gluebi->mtd.size = vi->used_bytes; + mutex_unlock(&devices_mutex); + return 0; +} + +/** + * gluebi_resized - UBI volume was re-sized notifier. + * @vi: volume info structure + * + * This function is called every time an UBI volume is re-size. It changes the + * corresponding fake MTD device size. This function returns zero in case of + * success and a negative error code in case of error. + */ +static int gluebi_resized(struct ubi_volume_info *vi) +{ + struct gluebi_device *gluebi; + + mutex_lock(&devices_mutex); + gluebi = find_gluebi_nolock(vi->ubi_num, vi->vol_id); + if (!gluebi) { + mutex_unlock(&devices_mutex); + err_msg("got update notification for unknown UBI device %d " + "volume %d", vi->ubi_num, vi->vol_id); + return -ENOENT; + } + gluebi->mtd.size = vi->used_bytes; + mutex_unlock(&devices_mutex); + return 0; +} + +/** + * gluebi_notify - UBI notification handler. + * @nb: registered notifier block + * @l: notification type + * @ptr: pointer to the &struct ubi_notification object */ -void ubi_gluebi_updated(struct ubi_volume *vol) +static int gluebi_notify(struct notifier_block *nb, unsigned long l, + void *ns_ptr) { - struct mtd_info *mtd = &vol->gluebi_mtd; + struct ubi_notification *nt = ns_ptr; + + switch (l) { + case UBI_VOLUME_ADDED: + gluebi_create(&nt->di, &nt->vi); + break; + case UBI_VOLUME_REMOVED: + gluebi_remove(&nt->vi); + break; + case UBI_VOLUME_RESIZED: + gluebi_resized(&nt->vi); + break; + case UBI_VOLUME_UPDATED: + gluebi_updated(&nt->vi); + break; + default: + break; + } + return NOTIFY_OK; +} - if (vol->vol_type == UBI_STATIC_VOLUME) - mtd->size = vol->used_bytes; +static struct notifier_block gluebi_notifier = { + .notifier_call = gluebi_notify, +}; + +static int __init ubi_gluebi_init(void) +{ + return ubi_register_volume_notifier(&gluebi_notifier, 0); } + +static void __exit ubi_gluebi_exit(void) +{ + struct gluebi_device *gluebi, *g; + + list_for_each_entry_safe(gluebi, g, &gluebi_devices, list) { + int err; + struct mtd_info *mtd = &gluebi->mtd; + + err = del_mtd_device(mtd); + if (err) + err_msg("error %d while removing gluebi MTD device %d, " + "UBI device %d, volume %d - ignoring", err, + mtd->index, gluebi->ubi_num, gluebi->vol_id); + kfree(mtd->name); + kfree(gluebi); + } + ubi_unregister_volume_notifier(&gluebi_notifier); +} + +module_init(ubi_gluebi_init); +module_exit(ubi_gluebi_exit); +MODULE_DESCRIPTION("MTD emulation layer over UBI volumes"); +MODULE_AUTHOR("Artem Bityutskiy, Joern Engel"); +MODULE_LICENSE("GPL"); |