| Message ID | 1243874925.5847.3.camel@localhost.localdomain |
|---|---|
| State | New, archived |
| Headers | show |
Hello Artem, Thanks for paying attention on this; the patch looks ok for me. > I've re-worked your patch. I make it release resources when the module > is unloaded, made it do proper module referencing, made it really > independent on UBI, tested it with the UBI test-suite which can be > found in ubi-2.6.git/tests/ubi-tests, re-named most of the > funcs/variables to get rid of the "ubi" word and make names consistent. > > Patch is below as well as at the same "experimental" branch. If you > are OK with this, I'll push it forward. > > >From 855ef5c35df22a056fd6f76f0785726a64a664fa Mon Sep 17 00:00:00 2001 > From: Dmitry Pervushin <dpervushin@embeddedalley.com> > Date: Sun, 31 May 2009 18:32:59 +0400 > Subject: [PATCH] UBI: make gluebi a separate module > > Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com> > Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> > --- > drivers/mtd/ubi/Kconfig | 13 +- > drivers/mtd/ubi/Makefile | 2 +- > drivers/mtd/ubi/gluebi.c | 375 +++++++++++++++++++++++++++++++++++----------- > 3 files changed, 292 insertions(+), 98 deletions(-) > > diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig > index 3f06310..b1cd7a1 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 dd834e0..c9302a5 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 49cd55a..fa61a3a 100644 > --- a/drivers/mtd/ubi/gluebi.c > +++ b/drivers/mtd/ubi/gluebi.c > @@ -19,17 +19,68 @@ > */ > > /* > - * 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/sched.h> > #include <linux/math64.h> > -#include "ubi.h" > +#include <linux/module.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 +92,18 @@ > */ > 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 +112,8 @@ 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 +121,15 @@ 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 +142,15 @@ 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 +168,12 @@ 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 +183,7 @@ 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 +209,17 @@ 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 +234,7 @@ 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 +259,36 @@ 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 +303,38 @@ 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 +342,196 @@ 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"); > -- > 1.6.0.6 >
On Mon, 2009-06-01 at 21:07 +0400, dmitry pervushin wrote:
> Thanks for paying attention on this; the patch looks ok for me.
OK, thanks. Pushed the patches to ubi-2.6.git/master.
diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig index 3f06310..b1cd7a1 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 dd834e0..c9302a5 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 49cd55a..fa61a3a 100644 --- a/drivers/mtd/ubi/gluebi.c +++ b/drivers/mtd/ubi/gluebi.c @@ -19,17 +19,68 @@ */ /* - * 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/sched.h> #include <linux/math64.h> -#include "ubi.h" +#include <linux/module.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 +92,18 @@ */ 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 +112,8 @@ 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 +121,15 @@ 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 +142,15 @@ 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 +168,12 @@ 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 +183,7 @@ 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 +209,17 @@ 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 +234,7 @@ 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 +259,36 @@ 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 +303,38 @@ 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 +342,196 @@ 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");