/* * Copyright (c) International Business Machines Corp., 2006 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Author: Artem Bityutskiy (Битюцкий Артём) */ /* * The UBI Eraseblock Association (EBA) sub-system. * * 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 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 * stored in the volume identifier header. This means that each VID header has * a unique sequence number. The sequence number is only increased an we assume * 64 bits is enough to never overflow. */ #include <linux/slab.h> #include <linux/crc32.h> #include <linux/err.h> #include "ubi.h" /* Number of physical eraseblocks reserved for atomic LEB change operation */ #define EBA_RESERVED_PEBS 1 /** * next_sqnum - get next sequence number. * @ubi: UBI device description object * * This function returns next sequence number to use, which is just the current * global sequence counter value. It also increases the global sequence * counter. */ static unsigned long long next_sqnum(struct ubi_device *ubi) { unsigned long long sqnum; spin_lock(&ubi->ltree_lock); sqnum = ubi->global_sqnum++; spin_unlock(&ubi->ltree_lock); return sqnum; } /** * ubi_get_compat - get compatibility flags of a volume. * @ubi: UBI device description object * @vol_id: volume ID * * This function returns compatibility flags for an internal volume. User * volumes have no compatibility flags, so %0 is returned. */ static int ubi_get_compat(const struct ubi_device *ubi, int vol_id) { if (vol_id == UBI_LAYOUT_VOLUME_ID) return UBI_LAYOUT_VOLUME_COMPAT; return 0; } /** * ltree_lookup - look up the lock tree. * @ubi: UBI device description object * @vol_id: volume ID * @lnum: logical eraseblock number * * 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 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 ubi_ltree_entry *le; le = rb_entry(p, struct ubi_ltree_entry, rb); if (vol_id < le->vol_id) p = p->rb_left; else if (vol_id > le->vol_id) p = p->rb_right; else { if (lnum < le->lnum) p = p->rb_left; else if (lnum > le->lnum) p = p->rb_right; else return le; } } return NULL; } /** * ltree_add_entry - add new entry to the lock tree. * @ubi: UBI device description object * @vol_id: volume ID * @lnum: logical eraseblock number * * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the * lock tree. If such entry is already there, its usage counter is increased. * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation * failed. */ static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id, int lnum) { struct ubi_ltree_entry *le, *le1, *le_free; 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; spin_lock(&ubi->ltree_lock); le1 = ltree_lookup(ubi, vol_id, lnum); if (le1) { /* * This logical eraseblock is already locked. The newly * allocated lock entry is not needed. */ le_free = le; le = le1; } else { struct rb_node **p, *parent = NULL; /* * No lock entry, add the newly allocated one to the * @ubi->ltree RB-tree. */ le_free = NULL; p = &ubi->ltree.rb_node; while (*p) { parent = *p; le1 = rb_entry(parent, struct ubi_ltree_entry, rb); if (vol_id < le1->vol_id) p = &(*p)->rb_left; else if (vol_id > le1->vol_id) p = &(*p)->rb_right; else { ubi_assert(lnum != le1->lnum); if (lnum < le1->lnum) p = &(*p)->rb_left; else p = &(*p)->rb_right; } } rb_link_node(&le->rb, parent, p); rb_insert_color(&le->rb, &ubi->ltree); } le->users += 1; spin_unlock(&ubi->ltree_lock); kfree(le_free); return le; } /** * leb_read_lock - lock logical eraseblock for reading. * @ubi: UBI device description object * @vol_id: volume ID * @lnum: logical eraseblock number * * This function locks a logical eraseblock for reading. Returns zero in case * of success and a negative error code in case of failure. */ static int leb_read_lock(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); down_read(&le->mutex); return 0; } /** * leb_read_unlock - unlock logical eraseblock. * @ubi: UBI device description object * @vol_id: volume ID * @lnum: logical eraseblock number */ static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum) { 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); kfree(le); } spin_unlock(&ubi->ltree_lock); } /** * 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. Returns zero in case * of success and a negative error code in case of failure. */ static int leb_write_lock(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); down_write(&le->mutex); return 0; } /** * 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 * @lnum: logical eraseblock number */ static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum) { 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); kfree(le); } spin_unlock(&ubi->ltree_lock); } /** * ubi_eba_unmap_leb - un-map logical eraseblock. * @ubi: UBI device description object * @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, struct ubi_volume *vol, int lnum) { int err, pnum, vol_id = vol->vol_id; if (ubi->ro_mode) return -EROFS; err = leb_write_lock(ubi, vol_id, lnum); if (err) return err; pnum = vol->eba_tbl[lnum]; if (pnum < 0) /* This logical eraseblock is already unmapped */ goto out_unlock; dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum); vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED; err = ubi_wl_put_peb(ubi, pnum, 0); out_unlock: leb_write_unlock(ubi, vol_id, lnum); return err; } /** * ubi_eba_read_leb - read data. * @ubi: UBI device description object * @vol: volume description object * @lnum: logical eraseblock number * @buf: buffer to store the read data * @offset: offset from where to read * @len: how many bytes to read * @check: data CRC check flag * * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF * bytes. The @check flag only makes sense for static volumes and forces * eraseblock data CRC checking. * * In case of success this function returns zero. In case of a static volume, * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be * 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, struct ubi_volume *vol, int lnum, void *buf, int offset, int len, int check) { int err, pnum, scrub = 0, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; uint32_t uninitialized_var(crc); err = leb_read_lock(ubi, vol_id, lnum); if (err) return err; pnum = vol->eba_tbl[lnum]; if (pnum < 0) { /* * The logical eraseblock is not mapped, fill the whole buffer * with 0xFF bytes. The exception is static volumes for which * it is an error to read unmapped logical eraseblocks. */ dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)", len, offset, vol_id, lnum); leb_read_unlock(ubi, vol_id, lnum); ubi_assert(vol->vol_type != UBI_STATIC_VOLUME); memset(buf, 0xFF, len); return 0; } dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d", len, offset, vol_id, lnum, pnum); if (vol->vol_type == UBI_DYNAMIC_VOLUME) check = 0; retry: if (check) { vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) { err = -ENOMEM; goto out_unlock; } err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1); if (err && err != UBI_IO_BITFLIPS) { if (err > 0) { /* * The header is either absent or corrupted. * The former case means there is a bug - * switch to read-only mode just in case. * The latter case means a real corruption - we * 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); err = -EBADMSG; } else ubi_ro_mode(ubi); } goto out_free; } else if (err == UBI_IO_BITFLIPS) scrub = 1; ubi_assert(lnum < be32_to_cpu(vid_hdr->used_ebs)); ubi_assert(len == be32_to_cpu(vid_hdr->data_size)); crc = be32_to_cpu(vid_hdr->data_crc); ubi_free_vid_hdr(ubi, vid_hdr); } err = ubi_io_read_data(ubi, buf, pnum, offset, len); if (err) { if (err == UBI_IO_BITFLIPS) { scrub = 1; err = 0; } else if (err == -EBADMSG) { if (vol->vol_type == UBI_DYNAMIC_VOLUME) goto out_unlock; scrub = 1; if (!check) { ubi_msg("force data checking"); check = 1; goto retry; } } else goto out_unlock; } if (check) { uint32_t crc1 = crc32(UBI_CRC32_INIT, buf, len); if (crc1 != crc) { ubi_warn("CRC error: calculated %#08x, must be %#08x", crc1, crc); err = -EBADMSG; goto out_unlock; } } if (scrub) err = ubi_wl_scrub_peb(ubi, pnum); leb_read_unlock(ubi, vol_id, lnum); return err; out_free: ubi_free_vid_hdr(ubi, vid_hdr); out_unlock: leb_read_unlock(ubi, vol_id, lnum); return err; } /** * recover_peb - recover from write failure. * @ubi: UBI device description object * @pnum: the physical eraseblock to recover * @vol_id: volume ID * @lnum: logical eraseblock number * @buf: data which was not written because of the write failure * @offset: offset of the failed write * @len: how many bytes should have been written * * This function is called in case of a write failure and moves all good data * from the potentially bad physical eraseblock to a good physical eraseblock. * This function also writes the data which was not written due to the failure. * Returns new physical eraseblock number in case of success, and a negative * error code in case of failure. */ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum, const void *buf, int offset, int len) { int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0; struct ubi_volume *vol = ubi->volumes[idx]; struct ubi_vid_hdr *vid_hdr; vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) return -ENOMEM; retry: new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN); if (new_pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); return new_pnum; } ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum); err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1); if (err && err != UBI_IO_BITFLIPS) { if (err > 0) err = -EIO; goto out_put; } vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); if (err) goto write_error; data_size = offset + len; mutex_lock(&ubi->buf_mutex); memset(ubi->peb_buf1 + 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); if (err && err != UBI_IO_BITFLIPS) goto out_unlock; } memcpy(ubi->peb_buf1 + offset, buf, len); err = ubi_io_write_data(ubi, ubi->peb_buf1, 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); vol->eba_tbl[lnum] = new_pnum; ubi_wl_put_peb(ubi, pnum, 1); ubi_msg("data was successfully recovered"); return 0; out_unlock: mutex_unlock(&ubi->buf_mutex); out_put: ubi_wl_put_peb(ubi, new_pnum, 1); ubi_free_vid_hdr(ubi, vid_hdr); return err; write_error: /* * Bad luck? This physical eraseblock is bad too? Crud. Let's try to * get another one. */ ubi_warn("failed to write to PEB %d", new_pnum); ubi_wl_put_peb(ubi, new_pnum, 1); if (++tries > UBI_IO_RETRIES) { ubi_free_vid_hdr(ubi, vid_hdr); return err; } ubi_msg("try again"); goto retry; } /** * ubi_eba_write_leb - write data to dynamic volume. * @ubi: UBI device description object * @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. 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, struct ubi_volume *vol, int lnum, const void *buf, int offset, int len, int dtype) { int err, pnum, tries = 0, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; if (ubi->ro_mode) return -EROFS; err = leb_write_lock(ubi, vol_id, lnum); if (err) return err; pnum = vol->eba_tbl[lnum]; if (pnum >= 0) { dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d", len, offset, vol_id, lnum, pnum); err = ubi_io_write_data(ubi, buf, pnum, offset, len); 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); if (err) ubi_ro_mode(ubi); } leb_write_unlock(ubi, vol_id, lnum); return err; } /* * The logical eraseblock is not mapped. We have to get a free physical * eraseblock and write the volume identifier header there first. */ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) { leb_write_unlock(ubi, vol_id, lnum); return -ENOMEM; } vid_hdr->vol_type = UBI_VID_DYNAMIC; vid_hdr->sqnum = cpu_to_be64(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); if (pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); leb_write_unlock(ubi, vol_id, lnum); return pnum; } dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d", len, offset, vol_id, lnum, pnum); err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr); if (err) { ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", 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; } } vol->eba_tbl[lnum] = pnum; leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); return 0; write_error: if (err != -EIO || !ubi->bad_allowed) { ubi_ro_mode(ubi); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); return err; } /* * Fortunately, this is the first write operation to this physical * 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); if (err || ++tries > UBI_IO_RETRIES) { ubi_ro_mode(ubi); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); return err; } vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); ubi_msg("try another PEB"); goto retry; } /** * ubi_eba_write_leb_st - write data to static volume. * @ubi: UBI device description object * @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. 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 * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent * 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 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, struct ubi_volume *vol, int lnum, const void *buf, int len, int dtype, int used_ebs) { int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; uint32_t crc; if (ubi->ro_mode) return -EROFS; if (lnum == used_ebs - 1) /* 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 - 1))); vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) return -ENOMEM; err = leb_write_lock(ubi, vol_id, lnum); if (err) { ubi_free_vid_hdr(ubi, vid_hdr); return err; } vid_hdr->sqnum = cpu_to_be64(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); crc = crc32(UBI_CRC32_INIT, buf, data_size); vid_hdr->vol_type = UBI_VID_STATIC; vid_hdr->data_size = cpu_to_be32(data_size); vid_hdr->used_ebs = cpu_to_be32(used_ebs); vid_hdr->data_crc = cpu_to_be32(crc); retry: pnum = ubi_wl_get_peb(ubi, dtype); if (pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); leb_write_unlock(ubi, vol_id, lnum); return pnum; } dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d", len, vol_id, lnum, pnum, used_ebs); err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr); if (err) { ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", vol_id, lnum, pnum); goto write_error; } err = ubi_io_write_data(ubi, buf, pnum, 0, len); if (err) { ubi_warn("failed to write %d bytes of data to PEB %d", len, pnum); goto write_error; } ubi_assert(vol->eba_tbl[lnum] < 0); vol->eba_tbl[lnum] = pnum; leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); return 0; write_error: if (err != -EIO || !ubi->bad_allowed) { /* * This flash device does not admit of bad eraseblocks or * something nasty and unexpected happened. Switch to read-only * mode just in case. */ ubi_ro_mode(ubi); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); return err; } err = ubi_wl_put_peb(ubi, pnum, 1); if (err || ++tries > UBI_IO_RETRIES) { ubi_ro_mode(ubi); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); return err; } vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi)); ubi_msg("try another PEB"); goto retry; } /* * ubi_eba_atomic_leb_change - change logical eraseblock atomically. * @ubi: UBI device description object * @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 * data, which has to be aligned. This function guarantees that in case of an * unclean reboot the old contents is preserved. Returns zero in case of * success and a negative error code in case of failure. * * 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, struct ubi_volume *vol, int lnum, const void *buf, int len, int dtype) { 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, dtype); } vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); if (!vid_hdr) return -ENOMEM; mutex_lock(&ubi->alc_mutex); err = leb_write_lock(ubi, vol_id, lnum); if (err) goto out_mutex; vid_hdr->sqnum = cpu_to_be64(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); crc = crc32(UBI_CRC32_INIT, buf, len); vid_hdr->vol_type = UBI_VID_DYNAMIC; vid_hdr->data_size = cpu_to_be32(len); vid_hdr->copy_flag = 1; vid_hdr->data_crc = cpu_to_be32(crc); retry: pnum = ubi_wl_get_peb(ubi, dtype); if (pnum < 0) { err = pnum; goto out_leb_unlock; } dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d", vol_id, lnum, vol->eba_tbl[lnum], pnum); err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr); if (err) { ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", vol_id, lnum, pnum); goto write_error; } err = ubi_io_write_data(ubi, buf, pnum, 0, len); if (err) { ubi_warn("failed to write %d bytes of data to PEB %d", len, pnum); goto write_error; } if (vol->eba_tbl[lnum] >= 0) { err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 0); if (err) goto out_leb_unlock; } vol->eba_tbl[lnum] = pnum; out_leb_unlock: leb_write_unlock(ubi, vol_id, lnum); out_mutex: mutex_unlock(&ubi->alc_mutex); ubi_free_vid_hdr(ubi, vid_hdr); return err; write_error: if (err != -EIO || !ubi->bad_allowed) { /* * This flash device does not admit of bad eraseblocks or * something nasty and unexpected happened. Switch to read-only * mode just in case. */ ubi_ro_mode(ubi); goto out_leb_unlock; } err = ubi_wl_put_peb(ubi, 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)); ubi_msg("try another PEB"); goto retry; } /** * ubi_eba_copy_leb - copy logical eraseblock. * @ubi: UBI device description object * @from: physical eraseblock number from where to copy * @to: physical eraseblock number where to copy * @vid_hdr: VID header of the @from physical eraseblock * * This function copies logical eraseblock from physical eraseblock @from to * physical eraseblock @to. The @vid_hdr buffer may be changed by this * function. Returns: * o %0 in case of success; * o %1 if the operation was canceled because the volume is being deleted * or because the PEB was put meanwhile; * o %2 if the operation was canceled because there was a write error to the * target PEB; * o %-EAGAIN if the operation was canceled because a bit-flip was detected * in the target PEB; * 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, 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); if (vid_hdr->vol_type == UBI_VID_STATIC) { data_size = be32_to_cpu(vid_hdr->data_size); aldata_size = ALIGN(data_size, ubi->min_io_size); } else data_size = aldata_size = ubi->leb_size - be32_to_cpu(vid_hdr->data_pad); idx = vol_id2idx(ubi, vol_id); spin_lock(&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. */ vol = ubi->volumes[idx]; if (!vol) { /* No need to do further work, cancel */ dbg_eba("volume %d is being removed, cancel", vol_id); spin_unlock(&ubi->volumes_lock); return 1; } spin_unlock(&ubi->volumes_lock); /* * 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 %1. */ err = leb_write_trylock(ubi, vol_id, lnum); if (err) { dbg_eba("contention on LEB %d:%d, cancel", vol_id, lnum); return err; } /* * 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_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to " "PEB %d, cancel", vol_id, lnum, from, vol->eba_tbl[lnum]); err = 1; goto out_unlock_leb; } /* * OK, now the LEB is locked and we can safely start moving it. Since * this function utilizes the @ubi->peb1_buf buffer which is shared * with some other functions, so lock the buffer by taking the * @ubi->buf_mutex. */ mutex_lock(&ubi->buf_mutex); dbg_eba("read %d bytes of data", aldata_size); err = ubi_io_read_data(ubi, ubi->peb_buf1, 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_buf; } /* * Now we have got to calculate how much data we have to 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 * the first part. We must do this to avoid writing 0xFF bytes as it * may have some side-effects. And not only this. It is important not * to include those 0xFFs to CRC because later the they may be filled * by data. */ if (vid_hdr->vol_type == UBI_VID_DYNAMIC) aldata_size = data_size = ubi_calc_data_len(ubi, ubi->peb_buf1, data_size); cond_resched(); crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size); cond_resched(); /* * It may turn out to me 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. */ if (data_size > 0) { vid_hdr->copy_flag = 1; 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)); err = ubi_io_write_vid_hdr(ubi, to, vid_hdr); if (err) { if (err == -EIO) err = 2; 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); else err = -EAGAIN; goto out_unlock_buf; } if (data_size > 0) { err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size); if (err) { if (err == -EIO) err = 2; goto out_unlock_buf; } cond_resched(); /* * 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); if (err) { if (err != UBI_IO_BITFLIPS) ubi_warn("cannot read data back from PEB %d", to); else err = -EAGAIN; goto out_unlock_buf; } cond_resched(); if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) { ubi_warn("read data back from PEB %d and it is " "different", to); err = -EINVAL; goto out_unlock_buf; } } ubi_assert(vol->eba_tbl[lnum] == from); vol->eba_tbl[lnum] = to; 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 sub-system using scanning information. * @ubi: UBI device description object * @si: scanning 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 i, j, err, num_volumes; struct ubi_scan_volume *sv; struct ubi_volume *vol; struct ubi_scan_leb *seb; struct rb_node *rb; dbg_eba("initialize EBA sub-system"); spin_lock_init(&ubi->ltree_lock); mutex_init(&ubi->alc_mutex); ubi->ltree = RB_ROOT; ubi->global_sqnum = si->max_sqnum + 1; num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT; for (i = 0; i < num_volumes; i++) { vol = ubi->volumes[i]; if (!vol) continue; cond_resched(); vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL); if (!vol->eba_tbl) { err = -ENOMEM; goto out_free; } 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) continue; ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { if (seb->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; } } 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; 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); } else ubi->beb_rsvd_pebs = ubi->beb_rsvd_level; ubi->avail_pebs -= ubi->beb_rsvd_pebs; ubi->rsvd_pebs += ubi->beb_rsvd_pebs; } dbg_eba("EBA sub-system is initialized"); return 0; out_free: for (i = 0; i < num_volumes; i++) { if (!ubi->volumes[i]) continue; kfree(ubi->volumes[i]->eba_tbl); } return err; }