diff options
Diffstat (limited to 'drivers/mtd/ubi/eba.c')
| -rw-r--r-- | drivers/mtd/ubi/eba.c | 703 |
1 files changed, 441 insertions, 262 deletions
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 880fa369035..0e11671dadc 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -19,20 +19,20 @@ */ /* - * The UBI Eraseblock Association (EBA) unit. + * The UBI Eraseblock Association (EBA) sub-system. * - * This unit is responsible for I/O to/from logical eraseblock. + * This sub-system is responsible for I/O to/from logical eraseblock. * * Although in this implementation the EBA table is fully kept and managed in * RAM, which assumes poor scalability, it might be (partially) maintained on * flash in future implementations. * - * The EBA unit implements per-logical eraseblock locking. Before accessing a - * logical eraseblock it is locked for reading or writing. The per-logical - * eraseblock locking is implemented by means of the lock tree. The lock tree - * is an RB-tree which refers all the currently locked logical eraseblocks. The - * lock tree elements are &struct ltree_entry objects. They are indexed by - * (@vol_id, @lnum) pairs. + * The EBA sub-system implements per-logical eraseblock locking. Before + * accessing a logical eraseblock it is locked for reading or writing. The + * per-logical eraseblock locking is implemented by means of the lock tree. The + * lock tree is an RB-tree which refers all the currently locked logical + * eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects. + * They are indexed by (@vol_id, @lnum) pairs. * * EBA also maintains the global sequence counter which is incremented each * time a logical eraseblock is mapped to a physical eraseblock and it is @@ -50,29 +50,6 @@ #define EBA_RESERVED_PEBS 1 /** - * struct ltree_entry - an entry in the lock tree. - * @rb: links RB-tree nodes - * @vol_id: volume ID of the locked logical eraseblock - * @lnum: locked logical eraseblock number - * @users: how many tasks are using this logical eraseblock or wait for it - * @mutex: read/write mutex to implement read/write access serialization to - * the (@vol_id, @lnum) logical eraseblock - * - * When a logical eraseblock is being locked - corresponding &struct ltree_entry - * object is inserted to the lock tree (@ubi->ltree). - */ -struct ltree_entry { - struct rb_node rb; - int vol_id; - int lnum; - int users; - struct rw_semaphore mutex; -}; - -/* Slab cache for lock-tree entries */ -static struct kmem_cache *ltree_slab; - -/** * next_sqnum - get next sequence number. * @ubi: UBI device description object * @@ -80,7 +57,7 @@ static struct kmem_cache *ltree_slab; * global sequence counter value. It also increases the global sequence * counter. */ -static unsigned long long next_sqnum(struct ubi_device *ubi) +unsigned long long ubi_next_sqnum(struct ubi_device *ubi) { unsigned long long sqnum; @@ -101,7 +78,7 @@ static unsigned long long next_sqnum(struct ubi_device *ubi) */ static int ubi_get_compat(const struct ubi_device *ubi, int vol_id) { - if (vol_id == UBI_LAYOUT_VOL_ID) + if (vol_id == UBI_LAYOUT_VOLUME_ID) return UBI_LAYOUT_VOLUME_COMPAT; return 0; } @@ -112,20 +89,20 @@ static int ubi_get_compat(const struct ubi_device *ubi, int vol_id) * @vol_id: volume ID * @lnum: logical eraseblock number * - * This function returns a pointer to the corresponding &struct ltree_entry + * This function returns a pointer to the corresponding &struct ubi_ltree_entry * object if the logical eraseblock is locked and %NULL if it is not. * @ubi->ltree_lock has to be locked. */ -static struct ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id, - int lnum) +static struct ubi_ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id, + int lnum) { struct rb_node *p; p = ubi->ltree.rb_node; while (p) { - struct ltree_entry *le; + struct ubi_ltree_entry *le; - le = rb_entry(p, struct ltree_entry, rb); + le = rb_entry(p, struct ubi_ltree_entry, rb); if (vol_id < le->vol_id) p = p->rb_left; @@ -155,15 +132,17 @@ static struct ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id, * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation * failed. */ -static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id, - int lnum) +static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi, + int vol_id, int lnum) { - struct ltree_entry *le, *le1, *le_free; + struct ubi_ltree_entry *le, *le1, *le_free; - le = kmem_cache_alloc(ltree_slab, GFP_NOFS); + le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS); if (!le) return ERR_PTR(-ENOMEM); + le->users = 0; + init_rwsem(&le->mutex); le->vol_id = vol_id; le->lnum = lnum; @@ -189,7 +168,7 @@ static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id, p = &ubi->ltree.rb_node; while (*p) { parent = *p; - le1 = rb_entry(parent, struct ltree_entry, rb); + le1 = rb_entry(parent, struct ubi_ltree_entry, rb); if (vol_id < le1->vol_id) p = &(*p)->rb_left; @@ -210,9 +189,7 @@ static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id, le->users += 1; spin_unlock(&ubi->ltree_lock); - if (le_free) - kmem_cache_free(ltree_slab, le_free); - + kfree(le_free); return le; } @@ -227,7 +204,7 @@ static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id, */ static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum) { - struct ltree_entry *le; + struct ubi_ltree_entry *le; le = ltree_add_entry(ubi, vol_id, lnum); if (IS_ERR(le)) @@ -244,22 +221,18 @@ static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum) */ static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum) { - int free = 0; - struct ltree_entry *le; + struct ubi_ltree_entry *le; spin_lock(&ubi->ltree_lock); le = ltree_lookup(ubi, vol_id, lnum); le->users -= 1; ubi_assert(le->users >= 0); + up_read(&le->mutex); if (le->users == 0) { rb_erase(&le->rb, &ubi->ltree); - free = 1; + kfree(le); } spin_unlock(&ubi->ltree_lock); - - up_read(&le->mutex); - if (free) - kmem_cache_free(ltree_slab, le); } /** @@ -273,7 +246,7 @@ static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum) */ static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum) { - struct ltree_entry *le; + struct ubi_ltree_entry *le; le = ltree_add_entry(ubi, vol_id, lnum); if (IS_ERR(le)) @@ -283,6 +256,40 @@ static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum) } /** + * leb_write_lock - lock logical eraseblock for writing. + * @ubi: UBI device description object + * @vol_id: volume ID + * @lnum: logical eraseblock number + * + * This function locks a logical eraseblock for writing if there is no + * contention and does nothing if there is contention. Returns %0 in case of + * success, %1 in case of contention, and and a negative error code in case of + * failure. + */ +static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum) +{ + struct ubi_ltree_entry *le; + + le = ltree_add_entry(ubi, vol_id, lnum); + if (IS_ERR(le)) + return PTR_ERR(le); + if (down_write_trylock(&le->mutex)) + return 0; + + /* Contention, cancel */ + spin_lock(&ubi->ltree_lock); + le->users -= 1; + ubi_assert(le->users >= 0); + if (le->users == 0) { + rb_erase(&le->rb, &ubi->ltree); + kfree(le); + } + spin_unlock(&ubi->ltree_lock); + + return 1; +} + +/** * leb_write_unlock - unlock logical eraseblock. * @ubi: UBI device description object * @vol_id: volume ID @@ -290,39 +297,34 @@ static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum) */ static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum) { - int free; - struct ltree_entry *le; + struct ubi_ltree_entry *le; spin_lock(&ubi->ltree_lock); le = ltree_lookup(ubi, vol_id, lnum); le->users -= 1; ubi_assert(le->users >= 0); + up_write(&le->mutex); if (le->users == 0) { rb_erase(&le->rb, &ubi->ltree); - free = 1; - } else - free = 0; + kfree(le); + } spin_unlock(&ubi->ltree_lock); - - up_write(&le->mutex); - if (free) - kmem_cache_free(ltree_slab, le); } /** * ubi_eba_unmap_leb - un-map logical eraseblock. * @ubi: UBI device description object - * @vol_id: volume ID + * @vol: volume description object * @lnum: logical eraseblock number * * This function un-maps logical eraseblock @lnum and schedules corresponding * physical eraseblock for erasure. Returns zero in case of success and a * negative error code in case of failure. */ -int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum) +int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol, + int lnum) { - int idx = vol_id2idx(ubi, vol_id), err, pnum; - struct ubi_volume *vol = ubi->volumes[idx]; + int err, pnum, vol_id = vol->vol_id; if (ubi->ro_mode) return -EROFS; @@ -338,8 +340,10 @@ int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum) dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum); + down_read(&ubi->fm_sem); vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED; - err = ubi_wl_put_peb(ubi, pnum, 0); + up_read(&ubi->fm_sem); + err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0); out_unlock: leb_write_unlock(ubi, vol_id, lnum); @@ -349,7 +353,7 @@ out_unlock: /** * ubi_eba_read_leb - read data. * @ubi: UBI device description object - * @vol_id: volume ID + * @vol: volume description object * @lnum: logical eraseblock number * @buf: buffer to store the read data * @offset: offset from where to read @@ -365,12 +369,11 @@ out_unlock: * returned for any volume type if an ECC error was detected by the MTD device * driver. Other negative error cored may be returned in case of other errors. */ -int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf, - int offset, int len, int check) +int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + void *buf, int offset, int len, int check) { - int err, pnum, scrub = 0, idx = vol_id2idx(ubi, vol_id); + int err, pnum, scrub = 0, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; - struct ubi_volume *vol = ubi->volumes[idx]; uint32_t uninitialized_var(crc); err = leb_read_lock(ubi, vol_id, lnum); @@ -417,9 +420,10 @@ retry: * may try to recover data. FIXME: but this is * not implemented. */ - if (err == UBI_IO_BAD_VID_HDR) { - ubi_warn("bad VID header at PEB %d, LEB" - "%d:%d", pnum, vol_id, lnum); + if (err == UBI_IO_BAD_HDR_EBADMSG || + err == UBI_IO_BAD_HDR) { + ubi_warn("corrupted VID header at PEB %d, LEB %d:%d", + pnum, vol_id, lnum); err = -EBADMSG; } else ubi_ro_mode(ubi); @@ -440,7 +444,7 @@ retry: if (err == UBI_IO_BITFLIPS) { scrub = 1; err = 0; - } else if (err == -EBADMSG) { + } else if (mtd_is_eccerr(err)) { if (vol->vol_type == UBI_DYNAMIC_VOLUME) goto out_unlock; scrub = 1; @@ -500,16 +504,12 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum, struct ubi_vid_hdr *vid_hdr; vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); - if (!vid_hdr) { + if (!vid_hdr) return -ENOMEM; - } - - mutex_lock(&ubi->buf_mutex); retry: - new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN); + new_pnum = ubi_wl_get_peb(ubi); if (new_pnum < 0) { - mutex_unlock(&ubi->buf_mutex); ubi_free_vid_hdr(ubi, vid_hdr); return new_pnum; } @@ -523,39 +523,45 @@ retry: goto out_put; } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); if (err) goto write_error; data_size = offset + len; - memset(ubi->peb_buf1 + offset, 0xFF, len); + mutex_lock(&ubi->buf_mutex); + memset(ubi->peb_buf + offset, 0xFF, len); /* Read everything before the area where the write failure happened */ if (offset > 0) { - err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset); + err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, offset); if (err && err != UBI_IO_BITFLIPS) - goto out_put; + goto out_unlock; } - memcpy(ubi->peb_buf1 + offset, buf, len); + memcpy(ubi->peb_buf + offset, buf, len); - err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size); - if (err) + err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size); + if (err) { + mutex_unlock(&ubi->buf_mutex); goto write_error; + } mutex_unlock(&ubi->buf_mutex); ubi_free_vid_hdr(ubi, vid_hdr); + down_read(&ubi->fm_sem); vol->eba_tbl[lnum] = new_pnum; - ubi_wl_put_peb(ubi, pnum, 1); + up_read(&ubi->fm_sem); + ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); ubi_msg("data was successfully recovered"); return 0; -out_put: +out_unlock: mutex_unlock(&ubi->buf_mutex); - ubi_wl_put_peb(ubi, new_pnum, 1); +out_put: + ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1); ubi_free_vid_hdr(ubi, vid_hdr); return err; @@ -565,9 +571,8 @@ write_error: * get another one. */ ubi_warn("failed to write to PEB %d", new_pnum); - ubi_wl_put_peb(ubi, new_pnum, 1); + ubi_wl_put_peb(ubi, vol_id, lnum, new_pnum, 1); if (++tries > UBI_IO_RETRIES) { - mutex_unlock(&ubi->buf_mutex); ubi_free_vid_hdr(ubi, vid_hdr); return err; } @@ -578,23 +583,21 @@ write_error: /** * ubi_eba_write_leb - write data to dynamic volume. * @ubi: UBI device description object - * @vol_id: volume ID + * @vol: volume description object * @lnum: logical eraseblock number * @buf: the data to write * @offset: offset within the logical eraseblock where to write * @len: how many bytes to write - * @dtype: data type * * This function writes data to logical eraseblock @lnum of a dynamic volume - * @vol_id. Returns zero in case of success and a negative error code in case + * @vol. Returns zero in case of success and a negative error code in case * of failure. In case of error, it is possible that something was still * written to the flash media, but may be some garbage. */ -int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum, - const void *buf, int offset, int len, int dtype) +int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + const void *buf, int offset, int len) { - int idx = vol_id2idx(ubi, vol_id), err, pnum, tries = 0; - struct ubi_volume *vol = ubi->volumes[idx]; + int err, pnum, tries = 0, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; if (ubi->ro_mode) @@ -613,7 +616,8 @@ int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum, if (err) { ubi_warn("failed to write data to PEB %d", pnum); if (err == -EIO && ubi->bad_allowed) - err = recover_peb(ubi, pnum, vol_id, lnum, buf, offset, len); + err = recover_peb(ubi, pnum, vol_id, lnum, buf, + offset, len); if (err) ubi_ro_mode(ubi); } @@ -632,14 +636,14 @@ int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum, } vid_hdr->vol_type = UBI_VID_DYNAMIC; - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); vid_hdr->vol_id = cpu_to_be32(vol_id); vid_hdr->lnum = cpu_to_be32(lnum); vid_hdr->compat = ubi_get_compat(ubi, vol_id); vid_hdr->data_pad = cpu_to_be32(vol->data_pad); retry: - pnum = ubi_wl_get_peb(ubi, dtype); + pnum = ubi_wl_get_peb(ubi); if (pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); leb_write_unlock(ubi, vol_id, lnum); @@ -656,14 +660,18 @@ retry: goto write_error; } - err = ubi_io_write_data(ubi, buf, pnum, offset, len); - if (err) { - ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, " - "PEB %d", len, offset, vol_id, lnum, pnum); - goto write_error; + if (len) { + err = ubi_io_write_data(ubi, buf, pnum, offset, len); + if (err) { + ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, PEB %d", + len, offset, vol_id, lnum, pnum); + goto write_error; + } } + down_read(&ubi->fm_sem); vol->eba_tbl[lnum] = pnum; + up_read(&ubi->fm_sem); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); @@ -682,7 +690,7 @@ write_error: * eraseblock, so just put it and request a new one. We assume that if * this physical eraseblock went bad, the erase code will handle that. */ - err = ubi_wl_put_peb(ubi, pnum, 1); + err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); if (err || ++tries > UBI_IO_RETRIES) { ubi_ro_mode(ubi); leb_write_unlock(ubi, vol_id, lnum); @@ -690,7 +698,7 @@ write_error: return err; } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); ubi_msg("try another PEB"); goto retry; } @@ -698,15 +706,14 @@ write_error: /** * ubi_eba_write_leb_st - write data to static volume. * @ubi: UBI device description object - * @vol_id: volume ID + * @vol: volume description object * @lnum: logical eraseblock number * @buf: data to write * @len: how many bytes to write - * @dtype: data type * @used_ebs: how many logical eraseblocks will this volume contain * * This function writes data to logical eraseblock @lnum of static volume - * @vol_id. The @used_ebs argument should contain total number of logical + * @vol. The @used_ebs argument should contain total number of logical * eraseblock in this static volume. * * When writing to the last logical eraseblock, the @len argument doesn't have @@ -714,16 +721,14 @@ write_error: * to the real data size, although the @buf buffer has to contain the * alignment. In all other cases, @len has to be aligned. * - * It is prohibited to write more then once to logical eraseblocks of static + * It is prohibited to write more than once to logical eraseblocks of static * volumes. This function returns zero in case of success and a negative error * code in case of failure. */ -int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum, - const void *buf, int len, int dtype, int used_ebs) +int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol, + int lnum, const void *buf, int len, int used_ebs) { - int err, pnum, tries = 0, data_size = len; - int idx = vol_id2idx(ubi, vol_id); - struct ubi_volume *vol = ubi->volumes[idx]; + int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; uint32_t crc; @@ -734,7 +739,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum, /* If this is the last LEB @len may be unaligned */ len = ALIGN(data_size, ubi->min_io_size); else - ubi_assert(len % ubi->min_io_size == 0); + ubi_assert(!(len & (ubi->min_io_size - 1))); vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) @@ -746,7 +751,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum, return err; } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); vid_hdr->vol_id = cpu_to_be32(vol_id); vid_hdr->lnum = cpu_to_be32(lnum); vid_hdr->compat = ubi_get_compat(ubi, vol_id); @@ -759,7 +764,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum, vid_hdr->data_crc = cpu_to_be32(crc); retry: - pnum = ubi_wl_get_peb(ubi, dtype); + pnum = ubi_wl_get_peb(ubi); if (pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); leb_write_unlock(ubi, vol_id, lnum); @@ -784,7 +789,9 @@ retry: } ubi_assert(vol->eba_tbl[lnum] < 0); + down_read(&ubi->fm_sem); vol->eba_tbl[lnum] = pnum; + up_read(&ubi->fm_sem); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); @@ -803,7 +810,7 @@ write_error: return err; } - err = ubi_wl_put_peb(ubi, pnum, 1); + err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); if (err || ++tries > UBI_IO_RETRIES) { ubi_ro_mode(ubi); leb_write_unlock(ubi, vol_id, lnum); @@ -811,7 +818,7 @@ write_error: return err; } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); ubi_msg("try another PEB"); goto retry; } @@ -819,11 +826,10 @@ write_error: /* * ubi_eba_atomic_leb_change - change logical eraseblock atomically. * @ubi: UBI device description object - * @vol_id: volume ID + * @vol: volume description object * @lnum: logical eraseblock number * @buf: data to write * @len: how many bytes to write - * @dtype: data type * * This function changes the contents of a logical eraseblock atomically. @buf * has to contain new logical eraseblock data, and @len - the length of the @@ -834,17 +840,27 @@ write_error: * UBI reserves one LEB for the "atomic LEB change" operation, so only one * LEB change may be done at a time. This is ensured by @ubi->alc_mutex. */ -int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum, - const void *buf, int len, int dtype) +int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, + int lnum, const void *buf, int len) { - int err, pnum, tries = 0, idx = vol_id2idx(ubi, vol_id); - struct ubi_volume *vol = ubi->volumes[idx]; + int err, pnum, tries = 0, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; uint32_t crc; if (ubi->ro_mode) return -EROFS; + if (len == 0) { + /* + * Special case when data length is zero. In this case the LEB + * has to be unmapped and mapped somewhere else. + */ + err = ubi_eba_unmap_leb(ubi, vol, lnum); + if (err) + return err; + return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0); + } + vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) return -ENOMEM; @@ -854,7 +870,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum, if (err) goto out_mutex; - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); vid_hdr->vol_id = cpu_to_be32(vol_id); vid_hdr->lnum = cpu_to_be32(lnum); vid_hdr->compat = ubi_get_compat(ubi, vol_id); @@ -867,7 +883,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum, vid_hdr->data_crc = cpu_to_be32(crc); retry: - pnum = ubi_wl_get_peb(ubi, dtype); + pnum = ubi_wl_get_peb(ubi); if (pnum < 0) { err = pnum; goto out_leb_unlock; @@ -891,12 +907,14 @@ retry: } if (vol->eba_tbl[lnum] >= 0) { - err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1); + err = ubi_wl_put_peb(ubi, vol_id, lnum, vol->eba_tbl[lnum], 0); if (err) goto out_leb_unlock; } + down_read(&ubi->fm_sem); vol->eba_tbl[lnum] = pnum; + up_read(&ubi->fm_sem); out_leb_unlock: leb_write_unlock(ubi, vol_id, lnum); @@ -916,29 +934,42 @@ write_error: goto out_leb_unlock; } - err = ubi_wl_put_peb(ubi, pnum, 1); + err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); if (err || ++tries > UBI_IO_RETRIES) { ubi_ro_mode(ubi); goto out_leb_unlock; } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); ubi_msg("try another PEB"); goto retry; } /** - * ltree_entry_ctor - lock tree entries slab cache constructor. - * @obj: the lock-tree entry to construct - * @cache: the lock tree entry slab cache - * @flags: constructor flags + * is_error_sane - check whether a read error is sane. + * @err: code of the error happened during reading + * + * This is a helper function for 'ubi_eba_copy_leb()' which is called when we + * cannot read data from the target PEB (an error @err happened). If the error + * code is sane, then we treat this error as non-fatal. Otherwise the error is + * fatal and UBI will be switched to R/O mode later. + * + * The idea is that we try not to switch to R/O mode if the read error is + * something which suggests there was a real read problem. E.g., %-EIO. Or a + * memory allocation failed (-%ENOMEM). Otherwise, it is safer to switch to R/O + * mode, simply because we do not know what happened at the MTD level, and we + * cannot handle this. E.g., the underlying driver may have become crazy, and + * it is safer to switch to R/O mode to preserve the data. + * + * And bear in mind, this is about reading from the target PEB, i.e. the PEB + * which we have just written. */ -static void ltree_entry_ctor(struct kmem_cache *cache, void *obj) +static int is_error_sane(int err) { - struct ltree_entry *le = obj; - - le->users = 0; - init_rwsem(&le->mutex); + if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR || + err == UBI_IO_BAD_HDR_EBADMSG || err == -ETIMEDOUT) + return 0; + return 1; } /** @@ -950,21 +981,22 @@ static void ltree_entry_ctor(struct kmem_cache *cache, void *obj) * * This function copies logical eraseblock from physical eraseblock @from to * physical eraseblock @to. The @vid_hdr buffer may be changed by this - * function. Returns zero in case of success, %UBI_IO_BITFLIPS if the operation - * was canceled because bit-flips were detected at the target PEB, and a - * negative error code in case of failure. + * function. Returns: + * o %0 in case of success; + * o %MOVE_CANCEL_RACE, %MOVE_TARGET_WR_ERR, %MOVE_TARGET_BITFLIPS, etc; + * o a negative error code in case of failure. */ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, struct ubi_vid_hdr *vid_hdr) { - int err, vol_id, lnum, data_size, aldata_size, pnum, idx; + int err, vol_id, lnum, data_size, aldata_size, idx; struct ubi_volume *vol; uint32_t crc; vol_id = be32_to_cpu(vid_hdr->vol_id); lnum = be32_to_cpu(vid_hdr->lnum); - dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to); + dbg_wl("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to); if (vid_hdr->vol_type == UBI_VID_STATIC) { data_size = be32_to_cpu(vid_hdr->data_size); @@ -973,55 +1005,73 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, data_size = aldata_size = ubi->leb_size - be32_to_cpu(vid_hdr->data_pad); - /* - * We do not want anybody to write to this logical eraseblock while we - * are moving it, so we lock it. - */ - err = leb_write_lock(ubi, vol_id, lnum); - if (err) - return err; - - mutex_lock(&ubi->buf_mutex); - - /* - * But the logical eraseblock might have been put by this time. - * Cancel if it is true. - */ idx = vol_id2idx(ubi, vol_id); - + spin_lock(&ubi->volumes_lock); /* - * We may race with volume deletion/re-size, so we have to hold - * @ubi->volumes_lock. + * Note, we may race with volume deletion, which means that the volume + * this logical eraseblock belongs to might be being deleted. Since the + * volume deletion un-maps all the volume's logical eraseblocks, it will + * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish. */ - spin_lock(&ubi->volumes_lock); vol = ubi->volumes[idx]; + spin_unlock(&ubi->volumes_lock); if (!vol) { - dbg_eba("volume %d was removed meanwhile", vol_id); - spin_unlock(&ubi->volumes_lock); - goto out_unlock; + /* No need to do further work, cancel */ + dbg_wl("volume %d is being removed, cancel", vol_id); + return MOVE_CANCEL_RACE; } - pnum = vol->eba_tbl[lnum]; - if (pnum != from) { - dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to " - "PEB %d, cancel", vol_id, lnum, from, pnum); - spin_unlock(&ubi->volumes_lock); - goto out_unlock; + /* + * We do not want anybody to write to this logical eraseblock while we + * are moving it, so lock it. + * + * Note, we are using non-waiting locking here, because we cannot sleep + * on the LEB, since it may cause deadlocks. Indeed, imagine a task is + * unmapping the LEB which is mapped to the PEB we are going to move + * (@from). This task locks the LEB and goes sleep in the + * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are + * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the + * LEB is already locked, we just do not move it and return + * %MOVE_RETRY. Note, we do not return %MOVE_CANCEL_RACE here because + * we do not know the reasons of the contention - it may be just a + * normal I/O on this LEB, so we want to re-try. + */ + err = leb_write_trylock(ubi, vol_id, lnum); + if (err) { + dbg_wl("contention on LEB %d:%d, cancel", vol_id, lnum); + return MOVE_RETRY; } - spin_unlock(&ubi->volumes_lock); - /* OK, now the LEB is locked and we can safely start moving it */ + /* + * The LEB might have been put meanwhile, and the task which put it is + * probably waiting on @ubi->move_mutex. No need to continue the work, + * cancel it. + */ + if (vol->eba_tbl[lnum] != from) { + dbg_wl("LEB %d:%d is no longer mapped to PEB %d, mapped to PEB %d, cancel", + vol_id, lnum, from, vol->eba_tbl[lnum]); + err = MOVE_CANCEL_RACE; + goto out_unlock_leb; + } - dbg_eba("read %d bytes of data", aldata_size); - err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size); + /* + * OK, now the LEB is locked and we can safely start moving it. Since + * this function utilizes the @ubi->peb_buf buffer which is shared + * with some other functions - we lock the buffer by taking the + * @ubi->buf_mutex. + */ + mutex_lock(&ubi->buf_mutex); + dbg_wl("read %d bytes of data", aldata_size); + err = ubi_io_read_data(ubi, ubi->peb_buf, from, 0, aldata_size); if (err && err != UBI_IO_BITFLIPS) { ubi_warn("error %d while reading data from PEB %d", err, from); - goto out_unlock; + err = MOVE_SOURCE_RD_ERR; + goto out_unlock_buf; } /* - * Now we have got to calculate how much data we have to to copy. In + * Now we have got to calculate how much data we have to copy. In * case of a static volume it is fairly easy - the VID header contains * the data size. In case of a dynamic volume it is more difficult - we * have to read the contents, cut 0xFF bytes from the end and copy only @@ -1032,14 +1082,14 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, */ if (vid_hdr->vol_type == UBI_VID_DYNAMIC) aldata_size = data_size = - ubi_calc_data_len(ubi, ubi->peb_buf1, data_size); + ubi_calc_data_len(ubi, ubi->peb_buf, data_size); cond_resched(); - crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size); + crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size); cond_resched(); /* - * It may turn out to me that the whole @from physical eraseblock + * It may turn out to be that the whole @from physical eraseblock * contains only 0xFF bytes. Then we have to only write the VID header * and do not write any data. This also means we should not set * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc. @@ -1049,26 +1099,37 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, vid_hdr->data_size = cpu_to_be32(data_size); vid_hdr->data_crc = cpu_to_be32(crc); } - vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); + vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); err = ubi_io_write_vid_hdr(ubi, to, vid_hdr); - if (err) - goto out_unlock; + if (err) { + if (err == -EIO) + err = MOVE_TARGET_WR_ERR; + goto out_unlock_buf; + } cond_resched(); /* Read the VID header back and check if it was written correctly */ err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1); if (err) { - if (err != UBI_IO_BITFLIPS) - ubi_warn("cannot read VID header back from PEB %d", to); - goto out_unlock; + if (err != UBI_IO_BITFLIPS) { + ubi_warn("error %d while reading VID header back from PEB %d", + err, to); + if (is_error_sane(err)) + err = MOVE_TARGET_RD_ERR; + } else + err = MOVE_TARGET_BITFLIPS; + goto out_unlock_buf; } if (data_size > 0) { - err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size); - if (err) - goto out_unlock; + err = ubi_io_write_data(ubi, ubi->peb_buf, to, 0, aldata_size); + if (err) { + if (err == -EIO) + err = MOVE_TARGET_WR_ERR; + goto out_unlock_buf; + } cond_resched(); @@ -1076,64 +1137,201 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, * We've written the data and are going to read it back to make * sure it was written correctly. */ - - err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size); + memset(ubi->peb_buf, 0xFF, aldata_size); + err = ubi_io_read_data(ubi, ubi->peb_buf, to, 0, aldata_size); if (err) { - if (err != UBI_IO_BITFLIPS) - ubi_warn("cannot read data back from PEB %d", - to); - goto out_unlock; + if (err != UBI_IO_BITFLIPS) { + ubi_warn("error %d while reading data back from PEB %d", + err, to); + if (is_error_sane(err)) + err = MOVE_TARGET_RD_ERR; + } else + err = MOVE_TARGET_BITFLIPS; + goto out_unlock_buf; } cond_resched(); - if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) { - ubi_warn("read data back from PEB %d - it is different", + if (crc != crc32(UBI_CRC32_INIT, ubi->peb_buf, data_size)) { + ubi_warn("read data back from PEB %d and it is different", to); - goto out_unlock; + err = -EINVAL; + goto out_unlock_buf; } } ubi_assert(vol->eba_tbl[lnum] == from); + down_read(&ubi->fm_sem); vol->eba_tbl[lnum] = to; + up_read(&ubi->fm_sem); -out_unlock: +out_unlock_buf: mutex_unlock(&ubi->buf_mutex); +out_unlock_leb: leb_write_unlock(ubi, vol_id, lnum); return err; } /** - * ubi_eba_init_scan - initialize the EBA unit using scanning information. + * print_rsvd_warning - warn about not having enough reserved PEBs. + * @ubi: UBI device description object + * + * This is a helper function for 'ubi_eba_init()' which is called when UBI + * cannot reserve enough PEBs for bad block handling. This function makes a + * decision whether we have to print a warning or not. The algorithm is as + * follows: + * o if this is a new UBI image, then just print the warning + * o if this is an UBI image which has already been used for some time, print + * a warning only if we can reserve less than 10% of the expected amount of + * the reserved PEB. + * + * The idea is that when UBI is used, PEBs become bad, and the reserved pool + * of PEBs becomes smaller, which is normal and we do not want to scare users + * with a warning every time they attach the MTD device. This was an issue + * reported by real users. + */ +static void print_rsvd_warning(struct ubi_device *ubi, + struct ubi_attach_info *ai) +{ + /* + * The 1 << 18 (256KiB) number is picked randomly, just a reasonably + * large number to distinguish between newly flashed and used images. + */ + if (ai->max_sqnum > (1 << 18)) { + int min = ubi->beb_rsvd_level / 10; + + if (!min) + min = 1; + if (ubi->beb_rsvd_pebs > min) + return; + } + + ubi_warn("cannot reserve enough PEBs for bad PEB handling, reserved %d, need %d", + ubi->beb_rsvd_pebs, ubi->beb_rsvd_level); + if (ubi->corr_peb_count) + ubi_warn("%d PEBs are corrupted and not used", + ubi->corr_peb_count); +} + +/** + * self_check_eba - run a self check on the EBA table constructed by fastmap. * @ubi: UBI device description object - * @si: scanning information + * @ai_fastmap: UBI attach info object created by fastmap + * @ai_scan: UBI attach info object created by scanning + * + * Returns < 0 in case of an internal error, 0 otherwise. + * If a bad EBA table entry was found it will be printed out and + * ubi_assert() triggers. + */ +int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap, + struct ubi_attach_info *ai_scan) +{ + int i, j, num_volumes, ret = 0; + int **scan_eba, **fm_eba; + struct ubi_ainf_volume *av; + struct ubi_volume *vol; + struct ubi_ainf_peb *aeb; + struct rb_node *rb; + + num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT; + + scan_eba = kmalloc(sizeof(*scan_eba) * num_volumes, GFP_KERNEL); + if (!scan_eba) + return -ENOMEM; + + fm_eba = kmalloc(sizeof(*fm_eba) * num_volumes, GFP_KERNEL); + if (!fm_eba) { + kfree(scan_eba); + return -ENOMEM; + } + + for (i = 0; i < num_volumes; i++) { + vol = ubi->volumes[i]; + if (!vol) + continue; + + scan_eba[i] = kmalloc(vol->reserved_pebs * sizeof(**scan_eba), + GFP_KERNEL); + if (!scan_eba[i]) { + ret = -ENOMEM; + goto out_free; + } + + fm_eba[i] = kmalloc(vol->reserved_pebs * sizeof(**fm_eba), + GFP_KERNEL); + if (!fm_eba[i]) { + ret = -ENOMEM; + goto out_free; + } + + for (j = 0; j < vol->reserved_pebs; j++) + scan_eba[i][j] = fm_eba[i][j] = UBI_LEB_UNMAPPED; + + av = ubi_find_av(ai_scan, idx2vol_id(ubi, i)); + if (!av) + continue; + + ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) + scan_eba[i][aeb->lnum] = aeb->pnum; + + av = ubi_find_av(ai_fastmap, idx2vol_id(ubi, i)); + if (!av) + continue; + + ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) + fm_eba[i][aeb->lnum] = aeb->pnum; + + for (j = 0; j < vol->reserved_pebs; j++) { + if (scan_eba[i][j] != fm_eba[i][j]) { + if (scan_eba[i][j] == UBI_LEB_UNMAPPED || + fm_eba[i][j] == UBI_LEB_UNMAPPED) + continue; + + ubi_err("LEB:%i:%i is PEB:%i instead of %i!", + vol->vol_id, i, fm_eba[i][j], + scan_eba[i][j]); + ubi_assert(0); + } + } + } + +out_free: + for (i = 0; i < num_volumes; i++) { + if (!ubi->volumes[i]) + continue; + + kfree(scan_eba[i]); + kfree(fm_eba[i]); + } + + kfree(scan_eba); + kfree(fm_eba); + return ret; +} + +/** + * ubi_eba_init - initialize the EBA sub-system using attaching information. + * @ubi: UBI device description object + * @ai: attaching information * * This function returns zero in case of success and a negative error code in * case of failure. */ -int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) +int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai) { int i, j, err, num_volumes; - struct ubi_scan_volume *sv; + struct ubi_ainf_volume *av; struct ubi_volume *vol; - struct ubi_scan_leb *seb; + struct ubi_ainf_peb *aeb; struct rb_node *rb; - dbg_eba("initialize EBA unit"); + dbg_eba("initialize EBA sub-system"); spin_lock_init(&ubi->ltree_lock); mutex_init(&ubi->alc_mutex); ubi->ltree = RB_ROOT; - if (ubi_devices_cnt == 0) { - ltree_slab = kmem_cache_create("ubi_ltree_slab", - sizeof(struct ltree_entry), 0, - 0, <ree_entry_ctor); - if (!ltree_slab) - return -ENOMEM; - } - - ubi->global_sqnum = si->max_sqnum + 1; + ubi->global_sqnum = ai->max_sqnum + 1; num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT; for (i = 0; i < num_volumes; i++) { @@ -1153,30 +1351,40 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) for (j = 0; j < vol->reserved_pebs; j++) vol->eba_tbl[j] = UBI_LEB_UNMAPPED; - sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i)); - if (!sv) + av = ubi_find_av(ai, idx2vol_id(ubi, i)); + if (!av) continue; - ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { - if (seb->lnum >= vol->reserved_pebs) + ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) { + if (aeb->lnum >= vol->reserved_pebs) /* * This may happen in case of an unclean reboot * during re-size. */ - ubi_scan_move_to_list(sv, seb, &si->erase); - vol->eba_tbl[seb->lnum] = seb->pnum; + ubi_move_aeb_to_list(av, aeb, &ai->erase); + vol->eba_tbl[aeb->lnum] = aeb->pnum; } } + if (ubi->avail_pebs < EBA_RESERVED_PEBS) { + ubi_err("no enough physical eraseblocks (%d, need %d)", + ubi->avail_pebs, EBA_RESERVED_PEBS); + if (ubi->corr_peb_count) + ubi_err("%d PEBs are corrupted and not used", + ubi->corr_peb_count); + err = -ENOSPC; + goto out_free; + } + ubi->avail_pebs -= EBA_RESERVED_PEBS; + ubi->rsvd_pebs += EBA_RESERVED_PEBS; + if (ubi->bad_allowed) { ubi_calculate_reserved(ubi); if (ubi->avail_pebs < ubi->beb_rsvd_level) { /* No enough free physical eraseblocks */ ubi->beb_rsvd_pebs = ubi->avail_pebs; - ubi_warn("cannot reserve enough PEBs for bad PEB " - "handling, reserved %d, need %d", - ubi->beb_rsvd_pebs, ubi->beb_rsvd_level); + print_rsvd_warning(ubi, ai); } else ubi->beb_rsvd_pebs = ubi->beb_rsvd_level; @@ -1184,16 +1392,7 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) ubi->rsvd_pebs += ubi->beb_rsvd_pebs; } - if (ubi->avail_pebs < EBA_RESERVED_PEBS) { - ubi_err("no enough physical eraseblocks (%d, need %d)", - ubi->avail_pebs, EBA_RESERVED_PEBS); - err = -ENOSPC; - goto out_free; - } - ubi->avail_pebs -= EBA_RESERVED_PEBS; - ubi->rsvd_pebs += EBA_RESERVED_PEBS; - - dbg_eba("EBA unit is initialized"); + dbg_eba("EBA sub-system is initialized"); return 0; out_free: @@ -1201,27 +1400,7 @@ out_free: if (!ubi->volumes[i]) continue; kfree(ubi->volumes[i]->eba_tbl); + ubi->volumes[i]->eba_tbl = NULL; } - if (ubi_devices_cnt == 0) - kmem_cache_destroy(ltree_slab); return err; } - -/** - * ubi_eba_close - close EBA unit. - * @ubi: UBI device description object - */ -void ubi_eba_close(const struct ubi_device *ubi) -{ - int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT; - - dbg_eba("close EBA unit"); - - for (i = 0; i < num_volumes; i++) { - if (!ubi->volumes[i]) - continue; - kfree(ubi->volumes[i]->eba_tbl); - } - if (ubi_devices_cnt == 1) - kmem_cache_destroy(ltree_slab); -} |