litmus-rt.git - The LITMUS^RT kernel.

diff options

Diffstat (limited to 'drivers/spi/spi.c')

-rw-r--r--

1 files changed, 8 insertions, 9 deletions

         /* Lock queue and check for queue work */
         spin_lock_irqsave(&master->queue_lock, flags);
         if (list_empty(&master->queue) || !master->running) {
-                if (master->busy && master->unprepare_transfer_hardware) {
+                if (!master->busy) {
-                        ret = master->unprepare_transfer_hardware(master);
+                        spin_unlock_irqrestore(&master->queue_lock, flags);
-                        if (ret) {
+                        return;
-                                spin_unlock_irqrestore(&master->queue_lock, flags);
-                                dev_err(&master->dev,
-                                        "failed to unprepare transfer hardware\n");
-                                return;
-                        }
                 }
                 master->busy = false;
                 spin_unlock_irqrestore(&master->queue_lock, flags);
+                if (master->unprepare_transfer_hardware &&
+                    master->unprepare_transfer_hardware(master))
+                        dev_err(&master->dev,
+                                "failed to unprepare transfer hardware\n");
                 return;
         }
         acpi_status status;
         acpi_handle handle;
-        handle = ACPI_HANDLE(&master->dev);
+        handle = ACPI_HANDLE(master->dev.parent);
         if (!handle)
                 return;

/* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * 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., 51 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * Authors: Adrian Hunter * Artem Bityutskiy (Битюцкий Артём) */ /* * This file implements functions needed to recover from unclean un-mounts. * When UBIFS is mounted, it checks a flag on the master node to determine if * an un-mount was completed successfully. If not, the process of mounting * incorporates additional checking and fixing of on-flash data structures. * UBIFS always cleans away all remnants of an unclean un-mount, so that * errors do not accumulate. However UBIFS defers recovery if it is mounted * read-only, and the flash is not modified in that case. * * The general UBIFS approach to the recovery is that it recovers from * corruptions which could be caused by power cuts, but it refuses to recover * from corruption caused by other reasons. And UBIFS tries to distinguish * between these 2 reasons of corruptions and silently recover in the former * case and loudly complain in the latter case. * * UBIFS writes only to erased LEBs, so it writes only to the flash space * containing only 0xFFs. UBIFS also always writes strictly from the beginning * of the LEB to the end. And UBIFS assumes that the underlying flash media * writes in @c->max_write_size bytes at a time. * * Hence, if UBIFS finds a corrupted node at offset X, it expects only the min. * I/O unit corresponding to offset X to contain corrupted data, all the * following min. I/O units have to contain empty space (all 0xFFs). If this is * not true, the corruption cannot be the result of a power cut, and UBIFS * refuses to mount. */ #include <linux/crc32.h> #include <linux/slab.h> #include "ubifs.h" /** * is_empty - determine whether a buffer is empty (contains all 0xff). * @buf: buffer to clean * @len: length of buffer * * This function returns %1 if the buffer is empty (contains all 0xff) otherwise * %0 is returned. */ static int is_empty(void *buf, int len) { uint8_t *p = buf; int i; for (i = 0; i < len; i++) if (*p++ != 0xff) return 0; return 1; } /** * first_non_ff - find offset of the first non-0xff byte. * @buf: buffer to search in * @len: length of buffer * * This function returns offset of the first non-0xff byte in @buf or %-1 if * the buffer contains only 0xff bytes. */ static int first_non_ff(void *buf, int len) { uint8_t *p = buf; int i; for (i = 0; i < len; i++) if (*p++ != 0xff) return i; return -1; } /** * get_master_node - get the last valid master node allowing for corruption. * @c: UBIFS file-system description object * @lnum: LEB number * @pbuf: buffer containing the LEB read, is returned here * @mst: master node, if found, is returned here * @cor: corruption, if found, is returned here * * This function allocates a buffer, reads the LEB into it, and finds and * returns the last valid master node allowing for one area of corruption. * The corrupt area, if there is one, must be consistent with the assumption * that it is the result of an unclean unmount while the master node was being * written. Under those circumstances, it is valid to use the previously written * master node. * * This function returns %0 on success and a negative error code on failure. */ static int get_master_node(const struct ubifs_info *c, int lnum, void **pbuf, struct ubifs_mst_node **mst, void **cor) { const int sz = c->mst_node_alsz; int err, offs, len; void *sbuf, *buf; sbuf = vmalloc(c->leb_size); if (!sbuf) return -ENOMEM; err = ubifs_leb_read(c, lnum, sbuf, 0, c->leb_size, 0); if (err && err != -EBADMSG) goto out_free; /* Find the first position that is definitely not a node */ offs = 0; buf = sbuf; len = c->leb_size; while (offs + UBIFS_MST_NODE_SZ <= c->leb_size) { struct ubifs_ch *ch = buf; if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) break; offs += sz; buf += sz; len -= sz; } /* See if there was a valid master node before that */ if (offs) { int ret; offs -= sz; buf -= sz; len += sz; ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); if (ret != SCANNED_A_NODE && offs) { /* Could have been corruption so check one place back */ offs -= sz; buf -= sz; len += sz; ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); if (ret != SCANNED_A_NODE) /* * We accept only one area of corruption because * we are assuming that it was caused while * trying to write a master node. */ goto out_err; } if (ret == SCANNED_A_NODE) { struct ubifs_ch *ch = buf; if (ch->node_type != UBIFS_MST_NODE) goto out_err; dbg_rcvry("found a master node at %d:%d", lnum, offs); *mst = buf; offs += sz; buf += sz; len -= sz; } } /* Check for corruption */ if (offs < c->leb_size) { if (!is_empty(buf, min_t(int, len, sz))) { *cor = buf; dbg_rcvry("found corruption at %d:%d", lnum, offs); } offs += sz; buf += sz; len -= sz; } /* Check remaining empty space */ if (offs < c->leb_size) if (!is_empty(buf, len)) goto out_err; *pbuf = sbuf; return 0; out_err: err = -EINVAL; out_free: vfree(sbuf); *mst = NULL; *cor = NULL; return err; } /** * write_rcvrd_mst_node - write recovered master node. * @c: UBIFS file-system description object * @mst: master node * * This function returns %0 on success and a negative error code on failure. */ static int write_rcvrd_mst_node(struct ubifs_info *c, struct ubifs_mst_node *mst) { int err = 0, lnum = UBIFS_MST_LNUM, sz = c->mst_node_alsz; __le32 save_flags; dbg_rcvry("recovery"); save_flags = mst->flags; mst->flags |= cpu_to_le32(UBIFS_MST_RCVRY); ubifs_prepare_node(c, mst, UBIFS_MST_NODE_SZ, 1); err = ubifs_leb_change(c, lnum, mst, sz); if (err) goto out; err = ubifs_leb_change(c, lnum + 1, mst, sz); if (err) goto out; out: mst->flags = save_flags; return err; } /** * ubifs_recover_master_node - recover the master node. * @c: UBIFS file-system description object * * This function recovers the master node from corruption that may occur due to * an unclean unmount. * * This function returns %0 on success and a negative error code on failure. */ int ubifs_recover_master_node(struct ubifs_info *c) { void *buf1 = NULL, *buf2 = NULL, *cor1 = NULL, *cor2 = NULL; struct ubifs_mst_node *mst1 = NULL, *mst2 = NULL, *mst; const int sz = c->mst_node_alsz; int err, offs1, offs2; dbg_rcvry("recovery"); err = get_master_node(c, UBIFS_MST_LNUM, &buf1, &mst1, &cor1); if (err) goto out_free; err = get_master_node(c, UBIFS_MST_LNUM + 1, &buf2, &mst2, &cor2); if (err) goto out_free; if (mst1) { offs1 = (void *)mst1 - buf1; if ((le32_to_cpu(mst1->flags) & UBIFS_MST_RCVRY) && (offs1 == 0 && !cor1)) { /* * mst1 was written by recovery at offset 0 with no * corruption. */ dbg_rcvry("recovery recovery"); mst = mst1; } else if (mst2) { offs2 = (void *)mst2 - buf2; if (offs1 == offs2) { /* Same offset, so must be the same */ if (memcmp((void *)mst1 + UBIFS_CH_SZ, (void *)mst2 + UBIFS_CH_SZ, UBIFS_MST_NODE_SZ - UBIFS_CH_SZ)) goto out_err; mst = mst1; } else if (offs2 + sz == offs1) { /* 1st LEB was written, 2nd was not */ if (cor1) goto out_err; mst = mst1; } else if (offs1 == 0 && c->leb_size - offs2 - sz < sz) { /* 1st LEB was unmapped and written, 2nd not */ if (cor1) goto out_err; mst = mst1; } else goto out_err; } else { /* * 2nd LEB was unmapped and about to be written, so * there must be only one master node in the first LEB * and no corruption. */ if (offs1 != 0 || cor1) goto out_err; mst = mst1; } } else { if (!mst2) goto out_err; /* * 1st LEB was unmapped and about to be written, so there must * be no room left in 2nd LEB. */ offs2 = (void *)mst2 - buf2; if (offs2 + sz + sz <= c->leb_size) goto out_err; mst = mst2; } ubifs_msg("recovered master node from LEB %d", (mst == mst1 ? UBIFS_MST_LNUM : UBIFS_MST_LNUM + 1)); memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ); if (c->ro_mount) { /* Read-only mode. Keep a copy for switching to rw mode */ c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL); if (!c->rcvrd_mst_node) { err = -ENOMEM; goto out_free; } memcpy(c->rcvrd_mst_node, c->mst_node, UBIFS_MST_NODE_SZ); /* * We had to recover the master node, which means there was an * unclean reboot. However, it is possible that the master node * is clean at this point, i.e., %UBIFS_MST_DIRTY is not set. * E.g., consider the following chain of events: * * 1. UBIFS was cleanly unmounted, so the master node is clean * 2. UBIFS is being mounted R/W and starts changing the master * node in the first (%UBIFS_MST_LNUM). A power cut happens, * so this LEB ends up with some amount of garbage at the * end. * 3. UBIFS is being mounted R/O. We reach this place and * recover the master node from the second LEB * (%UBIFS_MST_LNUM + 1). But we cannot update the media * because we are being mounted R/O. We have to defer the * operation. * 4. However, this master node (@c->mst_node) is marked as * clean (since the step 1). And if we just return, the * mount code will be confused and won't recover the master * node when it is re-mounter R/W later. * * Thus, to force the recovery by marking the master node as * dirty. */ c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); } else { /* Write the recovered master node */ c->max_sqnum = le64_to_cpu(mst->ch.sqnum) - 1; err = write_rcvrd_mst_node(c, c->mst_node); if (err) goto out_free; } vfree(buf2); vfree(buf1); return 0; out_err: err = -EINVAL; out_free: ubifs_err("failed to recover master node"); if (mst1) { ubifs_err("dumping first master node"); ubifs_dump_node(c, mst1); } if (mst2) { ubifs_err("dumping second master node"); ubifs_dump_node(c, mst2); } vfree(buf2); vfree(buf1); return err; } /** * ubifs_write_rcvrd_mst_node - write the recovered master node. * @c: UBIFS file-system description object * * This function writes the master node that was recovered during mounting in * read-only mode and must now be written because we are remounting rw. * * This function returns %0 on success and a negative error code on failure. */ int ubifs_write_rcvrd_mst_node(struct ubifs_info *c) { int err; if (!c->rcvrd_mst_node) return 0; c->rcvrd_mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); err = write_rcvrd_mst_node(c, c->rcvrd_mst_node); if (err) return err; kfree(c->rcvrd_mst_node); c->rcvrd_mst_node = NULL; return 0; } /** * is_last_write - determine if an offset was in the last write to a LEB. * @c: UBIFS file-system description object * @buf: buffer to check * @offs: offset to check * * This function returns %1 if @offs was in the last write to the LEB whose data * is in @buf, otherwise %0 is returned. The determination is made by checking * for subsequent empty space starting from the next @c->max_write_size * boundary. */ static int is_last_write(const struct ubifs_info *c, void *buf, int offs) { int empty_offs, check_len; uint8_t *p; /* * Round up to the next @c->max_write_size boundary i.e. @offs is in * the last wbuf written. After that should be empty space. */ empty_offs = ALIGN(offs + 1, c->max_write_size); check_len = c->leb_size - empty_offs; p = buf + empty_offs - offs; return is_empty(p, check_len); } /** * clean_buf - clean the data from an LEB sitting in a buffer. * @c: UBIFS file-system description object * @buf: buffer to clean * @lnum: LEB number to clean * @offs: offset from which to clean * @len: length of buffer * * This function pads up to the next min_io_size boundary (if there is one) and * sets empty space to all 0xff. @buf, @offs and @len are updated to the next * @c->min_io_size boundary. */ static void clean_buf(const struct ubifs_info *c, void **buf, int lnum, int *offs, int *len) { int empty_offs, pad_len; lnum = lnum; dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs); ubifs_assert(!(*offs & 7)); empty_offs = ALIGN(*offs, c->min_io_size); pad_len = empty_offs - *offs; ubifs_pad(c, *buf, pad_len); *offs += pad_len; *buf += pad_len; *len -= pad_len; memset(*buf, 0xff, c->leb_size - empty_offs); } /** * no_more_nodes - determine if there are no more nodes in a buffer. * @c: UBIFS file-system description object * @buf: buffer to check * @len: length of buffer * @lnum: LEB number of the LEB from which @buf was read * @offs: offset from which @buf was read * * This function ensures that the corrupted node at @offs is the last thing * written to a LEB. This function returns %1 if more data is not found and * %0 if more data is found. */ static int no_more_nodes(const struct ubifs_info *c, void *buf, int len, int lnum, int offs) { struct ubifs_ch *ch = buf; int skip, dlen = le32_to_cpu(ch->len); /* Check for empty space after the corrupt node's common header */ skip = ALIGN(offs + UBIFS_CH_SZ, c->max_write_size) - offs; if (is_empty(buf + skip, len - skip)) return 1; /* * The area after the common header size is not empty, so the common * header must be intact. Check it. */ if (ubifs_check_node(c, buf, lnum, offs, 1, 0) != -EUCLEAN) { dbg_rcvry("unexpected bad common header at %d:%d", lnum, offs); return 0; } /* Now we know the corrupt node's length we can skip over it */ skip = ALIGN(offs + dlen, c->max_write_size) - offs; /* After which there should be empty space */ if (is_empty(buf + skip, len - skip)) return 1; dbg_rcvry("unexpected data at %d:%d", lnum, offs + skip); return 0; } /** * fix_unclean_leb - fix an unclean LEB. * @c: UBIFS file-system description object * @sleb: scanned LEB information * @start: offset where scan started */ static int fix_unclean_leb(struct ubifs_info *c, struct ubifs_scan_leb *sleb, int start) { int lnum = sleb->lnum, endpt = start; /* Get the end offset of the last node we are keeping */ if (!list_empty(&sleb->nodes)) { struct ubifs_scan_node *snod; snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); endpt = snod->offs + snod->len; } if (c->ro_mount && !c->remounting_rw) { /* Add to recovery list */ struct ubifs_unclean_leb *ucleb; dbg_rcvry("need to fix LEB %d start %d endpt %d", lnum, start, sleb->endpt); ucleb = kzalloc(sizeof(struct ubifs_unclean_leb), GFP_NOFS); if (!ucleb) return -ENOMEM; ucleb->lnum = lnum; ucleb->endpt = endpt; list_add_tail(&ucleb->list, &c->unclean_leb_list); } else { /* Write the fixed LEB back to flash */ int err; dbg_rcvry("fixing LEB %d start %d endpt %d", lnum, start, sleb->endpt); if (endpt == 0) { err = ubifs_leb_unmap(c, lnum); if (err) return err; } else { int len = ALIGN(endpt, c->min_io_size); if (start) { err = ubifs_leb_read(c, lnum, sleb->buf, 0, start, 1); if (err) return err; } /* Pad to min_io_size */ if (len > endpt) { int pad_len = len - ALIGN(endpt, 8); if (pad_len > 0) { void *buf = sleb->buf + len - pad_len; ubifs_pad(c, buf, pad_len); } } err = ubifs_leb_change(c, lnum, sleb->buf, len); if (err) return err; } } return 0; } /** * drop_last_group - drop the last group of nodes. * @sleb: scanned LEB information * @offs: offset of dropped nodes is returned here * * This is a helper function for 'ubifs_recover_leb()' which drops the last * group of nodes of the scanned LEB. */ static void drop_last_group(struct ubifs_scan_leb *sleb, int *offs) { while (!list_empty(&sleb->nodes)) { struct ubifs_scan_node *snod; struct ubifs_ch *ch; snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); ch = snod->node; if (ch->group_type != UBIFS_IN_NODE_GROUP) break; dbg_rcvry("dropping grouped node at %d:%d", sleb->lnum, snod->offs); *offs = snod->offs; list_del(&snod->list); kfree(snod); sleb->nodes_cnt -= 1; } } /** * drop_last_node - drop the last node. * @sleb: scanned LEB information * @offs: offset of dropped nodes is returned here * @grouped: non-zero if whole group of nodes have to be dropped * * This is a helper function for 'ubifs_recover_leb()' which drops the last * node of the scanned LEB. */ static void drop_last_node(struct ubifs_scan_leb *sleb, int *offs) { struct ubifs_scan_node *snod; if (!list_empty(&sleb->nodes)) { snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); dbg_rcvry("dropping last node at %d:%d", sleb->lnum, snod->offs); *offs = snod->offs; list_del(&snod->list); kfree(snod); sleb->nodes_cnt -= 1; } } /** * ubifs_recover_leb - scan and recover a LEB. * @c: UBIFS file-system description object * @lnum: LEB number * @offs: offset * @sbuf: LEB-sized buffer to use * @jhead: journal head number this LEB belongs to (%-1 if the LEB does not * belong to any journal head) * * This function does a scan of a LEB, but caters for errors that might have * been caused by the unclean unmount from which we are attempting to recover. * Returns %0 in case of success, %-EUCLEAN if an unrecoverable corruption is * found, and a negative error code in case of failure. */ struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf, int jhead) { int ret = 0, err, len = c->leb_size - offs, start = offs, min_io_unit; int grouped = jhead == -1 ? 0 : c->jheads[jhead].grouped; struct ubifs_scan_leb *sleb; void *buf = sbuf + offs; dbg_rcvry("%d:%d, jhead %d, grouped %d", lnum, offs, jhead, grouped); sleb = ubifs_start_scan(c, lnum, offs, sbuf); if (IS_ERR(sleb)) return sleb; ubifs_assert(len >= 8); while (len >= 8) { dbg_scan("look at LEB %d:%d (%d bytes left)", lnum, offs, len); cond_resched(); /* * Scan quietly until there is an error from which we cannot * recover */ ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); if (ret == SCANNED_A_NODE) { /* A valid node, and not a padding node */ struct ubifs_ch *ch = buf; int node_len; err = ubifs_add_snod(c, sleb, buf, offs); if (err) goto error; node_len = ALIGN(le32_to_cpu(ch->len), 8); offs += node_len; buf += node_len; len -= node_len; } else if (ret > 0) { /* Padding bytes or a valid padding node */ offs += ret; buf += ret; len -= ret; } else if (ret == SCANNED_EMPTY_SPACE || ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE || ret == SCANNED_A_CORRUPT_NODE) { dbg_rcvry("found corruption (%d) at %d:%d", ret, lnum, offs); break; } else { ubifs_err("unexpected return value %d", ret); err = -EINVAL; goto error; } } if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE) { if (!is_last_write(c, buf, offs)) goto corrupted_rescan; } else if (ret == SCANNED_A_CORRUPT_NODE) { if (!no_more_nodes(c, buf, len, lnum, offs)) goto corrupted_rescan; } else if (!is_empty(buf, len)) { if (!is_last_write(c, buf, offs)) { int corruption = first_non_ff(buf, len); /* * See header comment for this file for more * explanations about the reasons we have this check. */ ubifs_err("corrupt empty space LEB %d:%d, corruption " "starts at %d", lnum, offs, corruption); /* Make sure we dump interesting non-0xFF data */ offs += corruption; buf += corruption; goto corrupted; } } min_io_unit = round_down(offs, c->min_io_size); if (grouped) /* * If nodes are grouped, always drop the incomplete group at * the end. */ drop_last_group(sleb, &offs); if (jhead == GCHD) { /* * If this LEB belongs to the GC head then while we are in the * middle of the same min. I/O unit keep dropping nodes. So * basically, what we want is to make sure that the last min. * I/O unit where we saw the corruption is dropped completely * with all the uncorrupted nodes which may possibly sit there. * * In other words, let's name the min. I/O unit where the * corruption starts B, and the previous min. I/O unit A. The * below code tries to deal with a situation when half of B * contains valid nodes or the end of a valid node, and the * second half of B contains corrupted data or garbage. This * means that UBIFS had been writing to B just before the power * cut happened. I do not know how realistic is this scenario * that half of the min. I/O unit had been written successfully * and the other half not, but this is possible in our 'failure * mode emulation' infrastructure at least. * * So what is the problem, why we need to drop those nodes? Why * can't we just clean-up the second half of B by putting a * padding node there? We can, and this works fine with one * exception which was reproduced with power cut emulation * testing and happens extremely rarely. * * Imagine the file-system is full, we run GC which starts * moving valid nodes from LEB X to LEB Y (obviously, LEB Y is * the current GC head LEB). The @c->gc_lnum is -1, which means * that GC will retain LEB X and will try to continue. Imagine * that LEB X is currently the dirtiest LEB, and the amount of * used space in LEB Y is exactly the same as amount of free * space in LEB X. * * And a power cut happens when nodes are moved from LEB X to * LEB Y. We are here trying to recover LEB Y which is the GC * head LEB. We find the min. I/O unit B as described above. * Then we clean-up LEB Y by padding min. I/O unit. And later * 'ubifs_rcvry_gc_commit()' function fails, because it cannot * find a dirty LEB which could be GC'd into LEB Y! Even LEB X * does not match because the amount of valid nodes there does * not fit the free space in LEB Y any more! And this is * because of the padding node which we added to LEB Y. The * user-visible effect of this which I once observed and * analysed is that we cannot mount the file-system with * -ENOSPC error. * * So obviously, to make sure that situation does not happen we * should free min. I/O unit B in LEB Y completely and the last * used min. I/O unit in LEB Y should be A. This is basically * what the below code tries to do. */ while (offs > min_io_unit) drop_last_node(sleb, &offs); } buf = sbuf + offs; len = c->leb_size - offs; clean_buf(c, &buf, lnum, &offs, &len); ubifs_end_scan(c, sleb, lnum, offs); err = fix_unclean_leb(c, sleb, start); if (err) goto error; return sleb; corrupted_rescan: /* Re-scan the corrupted data with verbose messages */ ubifs_err("corruptio %d", ret); ubifs_scan_a_node(c, buf, len, lnum, offs, 1); corrupted: ubifs_scanned_corruption(c, lnum, offs, buf); err = -EUCLEAN; error: ubifs_err("LEB %d scanning failed", lnum); ubifs_scan_destroy(sleb); return ERR_PTR(err); } /** * get_cs_sqnum - get commit start sequence number. * @c: UBIFS file-system description object * @lnum: LEB number of commit start node * @offs: offset of commit start node * @cs_sqnum: commit start sequence number is returned here * * This function returns %0 on success and a negative error code on failure. */ static int get_cs_sqnum(struct ubifs_info *c, int lnum, int offs, unsigned long long *cs_sqnum) { struct ubifs_cs_node *cs_node = NULL; int err, ret; dbg_rcvry("at %d:%d", lnum, offs); cs_node = kmalloc(UBIFS_CS_NODE_SZ, GFP_KERNEL); if (!cs_node) return -ENOMEM; if (c->leb_size - offs < UBIFS_CS_NODE_SZ) goto out_err; err = ubifs_leb_read(c, lnum, (void *)cs_node, offs, UBIFS_CS_NODE_SZ, 0); if (err && err != -EBADMSG) goto out_free; ret = ubifs_scan_a_node(c, cs_node, UBIFS_CS_NODE_SZ, lnum, offs, 0); if (ret != SCANNED_A_NODE) { ubifs_err("Not a valid node"); goto out_err; } if (cs_node->ch.node_type != UBIFS_CS_NODE) { ubifs_err("Node a CS node, type is %d", cs_node->ch.node_type); goto out_err; } if (le64_to_cpu(cs_node->cmt_no) != c->cmt_no) { ubifs_err("CS node cmt_no %llu != current cmt_no %llu", (unsigned long long)le64_to_cpu(cs_node->cmt_no), c->cmt_no); goto out_err; } *cs_sqnum = le64_to_cpu(cs_node->ch.sqnum); dbg_rcvry("commit start sqnum %llu", *cs_sqnum); kfree(cs_node); return 0; out_err: err = -EINVAL; out_free: ubifs_err("failed to get CS sqnum"); kfree(cs_node); return err; } /** * ubifs_recover_log_leb - scan and recover a log LEB. * @c: UBIFS file-system description object * @lnum: LEB number * @offs: offset * @sbuf: LEB-sized buffer to use * * This function does a scan of a LEB, but caters for errors that might have * been caused by unclean reboots from which we are attempting to recover * (assume that only the last log LEB can be corrupted by an unclean reboot). * * This function returns %0 on success and a negative error code on failure. */ struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf) { struct ubifs_scan_leb *sleb; int next_lnum; dbg_rcvry("LEB %d", lnum); next_lnum = lnum + 1; if (next_lnum >= UBIFS_LOG_LNUM + c->log_lebs) next_lnum = UBIFS_LOG_LNUM; if (next_lnum != c->ltail_lnum) { /* * We can only recover at the end of the log, so check that the * next log LEB is empty or out of date. */ sleb = ubifs_scan(c, next_lnum, 0, sbuf, 0); if (IS_ERR(sleb)) return sleb; if (sleb->nodes_cnt) { struct ubifs_scan_node *snod; unsigned long long cs_sqnum = c->cs_sqnum; snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list); if (cs_sqnum == 0) { int err; err = get_cs_sqnum(c, lnum, offs, &cs_sqnum); if (err) { ubifs_scan_destroy(sleb); return ERR_PTR(err); } } if (snod->sqnum > cs_sqnum) { ubifs_err("unrecoverable log corruption " "in LEB %d", lnum); ubifs_scan_destroy(sleb); return ERR_PTR(-EUCLEAN); } } ubifs_scan_destroy(sleb); } return ubifs_recover_leb(c, lnum, offs, sbuf, -1); } /** * recover_head - recover a head. * @c: UBIFS file-system description object * @lnum: LEB number of head to recover * @offs: offset of head to recover * @sbuf: LEB-sized buffer to use * * This function ensures that there is no data on the flash at a head location. * * This function returns %0 on success and a negative error code on failure. */ static int recover_head(struct ubifs_info *c, int lnum, int offs, void *sbuf) { int len = c->max_write_size, err; if (offs + len > c->leb_size) len = c->leb_size - offs; if (!len) return 0; /* Read at the head location and check it is empty flash */ err = ubifs_leb_read(c, lnum, sbuf, offs, len, 1); if (err || !is_empty(sbuf, len)) { dbg_rcvry("cleaning head at %d:%d", lnum, offs); if (offs == 0) return ubifs_leb_unmap(c, lnum); err = ubifs_leb_read(c, lnum, sbuf, 0, offs, 1); if (err) return err; return ubifs_leb_change(c, lnum, sbuf, offs); } return 0; } /** * ubifs_recover_inl_heads - recover index and LPT heads. * @c: UBIFS file-system description object * @sbuf: LEB-sized buffer to use * * This function ensures that there is no data on the flash at the index and * LPT head locations. *


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