mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1554 lines
42 KiB
1554 lines
42 KiB
// SPDX-License-Identifier: GPL-2.0+ |
|
/* |
|
* This file is part of UBIFS. |
|
* |
|
* Copyright (C) 2006-2008 Nokia Corporation |
|
* |
|
* 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. |
|
*/ |
|
|
|
#ifndef __UBOOT__ |
|
#include <linux/crc32.h> |
|
#include <linux/slab.h> |
|
#else |
|
#include <linux/err.h> |
|
#endif |
|
#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(c, "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); |
|
#ifndef __UBOOT__ |
|
} 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; |
|
#endif |
|
} |
|
|
|
vfree(buf2); |
|
vfree(buf1); |
|
|
|
return 0; |
|
|
|
out_err: |
|
err = -EINVAL; |
|
out_free: |
|
ubifs_err(c, "failed to recover master node"); |
|
if (mst1) { |
|
ubifs_err(c, "dumping first master node"); |
|
ubifs_dump_node(c, mst1); |
|
} |
|
if (mst2) { |
|
ubifs_err(c, "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); |
|
#ifndef __UBOOT__ |
|
} 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; |
|
} |
|
#endif |
|
} |
|
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 |
|
* |
|
* 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 the scanned information on success and a negative error code on |
|
* 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(c, "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(c, "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(c, "corruption %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(c, "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(c, "Not a valid node"); |
|
goto out_err; |
|
} |
|
if (cs_node->ch.node_type != UBIFS_CS_NODE) { |
|
ubifs_err(c, "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(c, "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(c, "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(c, "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. |
|
* |
|
* This deals with the recovery of a half-completed journal commit. UBIFS is |
|
* careful never to overwrite the last version of the index or the LPT. Because |
|
* the index and LPT are wandering trees, data from a half-completed commit will |
|
* not be referenced anywhere in UBIFS. The data will be either in LEBs that are |
|
* assumed to be empty and will be unmapped anyway before use, or in the index |
|
* and LPT heads. |
|
* |
|
* This function returns %0 on success and a negative error code on failure. |
|
*/ |
|
int ubifs_recover_inl_heads(struct ubifs_info *c, void *sbuf) |
|
{ |
|
int err; |
|
|
|
ubifs_assert(!c->ro_mount || c->remounting_rw); |
|
|
|
dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs); |
|
err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf); |
|
if (err) |
|
return err; |
|
|
|
dbg_rcvry("checking LPT head at %d:%d", c->nhead_lnum, c->nhead_offs); |
|
|
|
return recover_head(c, c->nhead_lnum, c->nhead_offs, sbuf); |
|
} |
|
|
|
/** |
|
* clean_an_unclean_leb - read and write a LEB to remove corruption. |
|
* @c: UBIFS file-system description object |
|
* @ucleb: unclean LEB information |
|
* @sbuf: LEB-sized buffer to use |
|
* |
|
* This function reads a LEB up to a point pre-determined by the mount recovery, |
|
* checks the nodes, and writes the result back to the flash, thereby cleaning |
|
* off any following corruption, or non-fatal ECC errors. |
|
* |
|
* This function returns %0 on success and a negative error code on failure. |
|
*/ |
|
static int clean_an_unclean_leb(struct ubifs_info *c, |
|
struct ubifs_unclean_leb *ucleb, void *sbuf) |
|
{ |
|
int err, lnum = ucleb->lnum, offs = 0, len = ucleb->endpt, quiet = 1; |
|
void *buf = sbuf; |
|
|
|
dbg_rcvry("LEB %d len %d", lnum, len); |
|
|
|
if (len == 0) { |
|
/* Nothing to read, just unmap it */ |
|
return ubifs_leb_unmap(c, lnum); |
|
} |
|
|
|
err = ubifs_leb_read(c, lnum, buf, offs, len, 0); |
|
if (err && err != -EBADMSG) |
|
return err; |
|
|
|
while (len >= 8) { |
|
int ret; |
|
|
|
cond_resched(); |
|
|
|
/* Scan quietly until there is an error */ |
|
ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet); |
|
|
|
if (ret == SCANNED_A_NODE) { |
|
/* A valid node, and not a padding node */ |
|
struct ubifs_ch *ch = buf; |
|
int node_len; |
|
|
|
node_len = ALIGN(le32_to_cpu(ch->len), 8); |
|
offs += node_len; |
|
buf += node_len; |
|
len -= node_len; |
|
continue; |
|
} |
|
|
|
if (ret > 0) { |
|
/* Padding bytes or a valid padding node */ |
|
offs += ret; |
|
buf += ret; |
|
len -= ret; |
|
continue; |
|
} |
|
|
|
if (ret == SCANNED_EMPTY_SPACE) { |
|
ubifs_err(c, "unexpected empty space at %d:%d", |
|
lnum, offs); |
|
return -EUCLEAN; |
|
} |
|
|
|
if (quiet) { |
|
/* Redo the last scan but noisily */ |
|
quiet = 0; |
|
continue; |
|
} |
|
|
|
ubifs_scanned_corruption(c, lnum, offs, buf); |
|
return -EUCLEAN; |
|
} |
|
|
|
/* Pad to min_io_size */ |
|
len = ALIGN(ucleb->endpt, c->min_io_size); |
|
if (len > ucleb->endpt) { |
|
int pad_len = len - ALIGN(ucleb->endpt, 8); |
|
|
|
if (pad_len > 0) { |
|
buf = c->sbuf + len - pad_len; |
|
ubifs_pad(c, buf, pad_len); |
|
} |
|
} |
|
|
|
/* Write back the LEB atomically */ |
|
err = ubifs_leb_change(c, lnum, sbuf, len); |
|
if (err) |
|
return err; |
|
|
|
dbg_rcvry("cleaned LEB %d", lnum); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ubifs_clean_lebs - clean LEBs recovered during read-only mount. |
|
* @c: UBIFS file-system description object |
|
* @sbuf: LEB-sized buffer to use |
|
* |
|
* This function cleans a LEB identified during recovery that needs to be |
|
* written but was not because UBIFS was mounted read-only. This happens when |
|
* remounting to read-write mode. |
|
* |
|
* This function returns %0 on success and a negative error code on failure. |
|
*/ |
|
int ubifs_clean_lebs(struct ubifs_info *c, void *sbuf) |
|
{ |
|
dbg_rcvry("recovery"); |
|
while (!list_empty(&c->unclean_leb_list)) { |
|
struct ubifs_unclean_leb *ucleb; |
|
int err; |
|
|
|
ucleb = list_entry(c->unclean_leb_list.next, |
|
struct ubifs_unclean_leb, list); |
|
err = clean_an_unclean_leb(c, ucleb, sbuf); |
|
if (err) |
|
return err; |
|
list_del(&ucleb->list); |
|
kfree(ucleb); |
|
} |
|
return 0; |
|
} |
|
|
|
#ifndef __UBOOT__ |
|
/** |
|
* grab_empty_leb - grab an empty LEB to use as GC LEB and run commit. |
|
* @c: UBIFS file-system description object |
|
* |
|
* This is a helper function for 'ubifs_rcvry_gc_commit()' which grabs an empty |
|
* LEB to be used as GC LEB (@c->gc_lnum), and then runs the commit. Returns |
|
* zero in case of success and a negative error code in case of failure. |
|
*/ |
|
static int grab_empty_leb(struct ubifs_info *c) |
|
{ |
|
int lnum, err; |
|
|
|
/* |
|
* Note, it is very important to first search for an empty LEB and then |
|
* run the commit, not vice-versa. The reason is that there might be |
|
* only one empty LEB at the moment, the one which has been the |
|
* @c->gc_lnum just before the power cut happened. During the regular |
|
* UBIFS operation (not now) @c->gc_lnum is marked as "taken", so no |
|
* one but GC can grab it. But at this moment this single empty LEB is |
|
* not marked as taken, so if we run commit - what happens? Right, the |
|
* commit will grab it and write the index there. Remember that the |
|
* index always expands as long as there is free space, and it only |
|
* starts consolidating when we run out of space. |
|
* |
|
* IOW, if we run commit now, we might not be able to find a free LEB |
|
* after this. |
|
*/ |
|
lnum = ubifs_find_free_leb_for_idx(c); |
|
if (lnum < 0) { |
|
ubifs_err(c, "could not find an empty LEB"); |
|
ubifs_dump_lprops(c); |
|
ubifs_dump_budg(c, &c->bi); |
|
return lnum; |
|
} |
|
|
|
/* Reset the index flag */ |
|
err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, |
|
LPROPS_INDEX, 0); |
|
if (err) |
|
return err; |
|
|
|
c->gc_lnum = lnum; |
|
dbg_rcvry("found empty LEB %d, run commit", lnum); |
|
|
|
return ubifs_run_commit(c); |
|
} |
|
|
|
/** |
|
* ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit. |
|
* @c: UBIFS file-system description object |
|
* |
|
* Out-of-place garbage collection requires always one empty LEB with which to |
|
* start garbage collection. The LEB number is recorded in c->gc_lnum and is |
|
* written to the master node on unmounting. In the case of an unclean unmount |
|
* the value of gc_lnum recorded in the master node is out of date and cannot |
|
* be used. Instead, recovery must allocate an empty LEB for this purpose. |
|
* However, there may not be enough empty space, in which case it must be |
|
* possible to GC the dirtiest LEB into the GC head LEB. |
|
* |
|
* This function also runs the commit which causes the TNC updates from |
|
* size-recovery and orphans to be written to the flash. That is important to |
|
* ensure correct replay order for subsequent mounts. |
|
* |
|
* This function returns %0 on success and a negative error code on failure. |
|
*/ |
|
int ubifs_rcvry_gc_commit(struct ubifs_info *c) |
|
{ |
|
struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; |
|
struct ubifs_lprops lp; |
|
int err; |
|
|
|
dbg_rcvry("GC head LEB %d, offs %d", wbuf->lnum, wbuf->offs); |
|
|
|
c->gc_lnum = -1; |
|
if (wbuf->lnum == -1 || wbuf->offs == c->leb_size) |
|
return grab_empty_leb(c); |
|
|
|
err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2); |
|
if (err) { |
|
if (err != -ENOSPC) |
|
return err; |
|
|
|
dbg_rcvry("could not find a dirty LEB"); |
|
return grab_empty_leb(c); |
|
} |
|
|
|
ubifs_assert(!(lp.flags & LPROPS_INDEX)); |
|
ubifs_assert(lp.free + lp.dirty >= wbuf->offs); |
|
|
|
/* |
|
* We run the commit before garbage collection otherwise subsequent |
|
* mounts will see the GC and orphan deletion in a different order. |
|
*/ |
|
dbg_rcvry("committing"); |
|
err = ubifs_run_commit(c); |
|
if (err) |
|
return err; |
|
|
|
dbg_rcvry("GC'ing LEB %d", lp.lnum); |
|
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
|
err = ubifs_garbage_collect_leb(c, &lp); |
|
if (err >= 0) { |
|
int err2 = ubifs_wbuf_sync_nolock(wbuf); |
|
|
|
if (err2) |
|
err = err2; |
|
} |
|
mutex_unlock(&wbuf->io_mutex); |
|
if (err < 0) { |
|
ubifs_err(c, "GC failed, error %d", err); |
|
if (err == -EAGAIN) |
|
err = -EINVAL; |
|
return err; |
|
} |
|
|
|
ubifs_assert(err == LEB_RETAINED); |
|
if (err != LEB_RETAINED) |
|
return -EINVAL; |
|
|
|
err = ubifs_leb_unmap(c, c->gc_lnum); |
|
if (err) |
|
return err; |
|
|
|
dbg_rcvry("allocated LEB %d for GC", lp.lnum); |
|
return 0; |
|
} |
|
#else |
|
int ubifs_rcvry_gc_commit(struct ubifs_info *c) |
|
{ |
|
return 0; |
|
} |
|
#endif |
|
|
|
/** |
|
* struct size_entry - inode size information for recovery. |
|
* @rb: link in the RB-tree of sizes |
|
* @inum: inode number |
|
* @i_size: size on inode |
|
* @d_size: maximum size based on data nodes |
|
* @exists: indicates whether the inode exists |
|
* @inode: inode if pinned in memory awaiting rw mode to fix it |
|
*/ |
|
struct size_entry { |
|
struct rb_node rb; |
|
ino_t inum; |
|
loff_t i_size; |
|
loff_t d_size; |
|
int exists; |
|
struct inode *inode; |
|
}; |
|
|
|
/** |
|
* add_ino - add an entry to the size tree. |
|
* @c: UBIFS file-system description object |
|
* @inum: inode number |
|
* @i_size: size on inode |
|
* @d_size: maximum size based on data nodes |
|
* @exists: indicates whether the inode exists |
|
*/ |
|
static int add_ino(struct ubifs_info *c, ino_t inum, loff_t i_size, |
|
loff_t d_size, int exists) |
|
{ |
|
struct rb_node **p = &c->size_tree.rb_node, *parent = NULL; |
|
struct size_entry *e; |
|
|
|
while (*p) { |
|
parent = *p; |
|
e = rb_entry(parent, struct size_entry, rb); |
|
if (inum < e->inum) |
|
p = &(*p)->rb_left; |
|
else |
|
p = &(*p)->rb_right; |
|
} |
|
|
|
e = kzalloc(sizeof(struct size_entry), GFP_KERNEL); |
|
if (!e) |
|
return -ENOMEM; |
|
|
|
e->inum = inum; |
|
e->i_size = i_size; |
|
e->d_size = d_size; |
|
e->exists = exists; |
|
|
|
rb_link_node(&e->rb, parent, p); |
|
rb_insert_color(&e->rb, &c->size_tree); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* find_ino - find an entry on the size tree. |
|
* @c: UBIFS file-system description object |
|
* @inum: inode number |
|
*/ |
|
static struct size_entry *find_ino(struct ubifs_info *c, ino_t inum) |
|
{ |
|
struct rb_node *p = c->size_tree.rb_node; |
|
struct size_entry *e; |
|
|
|
while (p) { |
|
e = rb_entry(p, struct size_entry, rb); |
|
if (inum < e->inum) |
|
p = p->rb_left; |
|
else if (inum > e->inum) |
|
p = p->rb_right; |
|
else |
|
return e; |
|
} |
|
return NULL; |
|
} |
|
|
|
/** |
|
* remove_ino - remove an entry from the size tree. |
|
* @c: UBIFS file-system description object |
|
* @inum: inode number |
|
*/ |
|
static void remove_ino(struct ubifs_info *c, ino_t inum) |
|
{ |
|
struct size_entry *e = find_ino(c, inum); |
|
|
|
if (!e) |
|
return; |
|
rb_erase(&e->rb, &c->size_tree); |
|
kfree(e); |
|
} |
|
|
|
/** |
|
* ubifs_destroy_size_tree - free resources related to the size tree. |
|
* @c: UBIFS file-system description object |
|
*/ |
|
void ubifs_destroy_size_tree(struct ubifs_info *c) |
|
{ |
|
struct size_entry *e, *n; |
|
|
|
rbtree_postorder_for_each_entry_safe(e, n, &c->size_tree, rb) { |
|
if (e->inode) |
|
iput(e->inode); |
|
kfree(e); |
|
} |
|
|
|
c->size_tree = RB_ROOT; |
|
} |
|
|
|
/** |
|
* ubifs_recover_size_accum - accumulate inode sizes for recovery. |
|
* @c: UBIFS file-system description object |
|
* @key: node key |
|
* @deletion: node is for a deletion |
|
* @new_size: inode size |
|
* |
|
* This function has two purposes: |
|
* 1) to ensure there are no data nodes that fall outside the inode size |
|
* 2) to ensure there are no data nodes for inodes that do not exist |
|
* To accomplish those purposes, a rb-tree is constructed containing an entry |
|
* for each inode number in the journal that has not been deleted, and recording |
|
* the size from the inode node, the maximum size of any data node (also altered |
|
* by truncations) and a flag indicating a inode number for which no inode node |
|
* was present in the journal. |
|
* |
|
* Note that there is still the possibility that there are data nodes that have |
|
* been committed that are beyond the inode size, however the only way to find |
|
* them would be to scan the entire index. Alternatively, some provision could |
|
* be made to record the size of inodes at the start of commit, which would seem |
|
* very cumbersome for a scenario that is quite unlikely and the only negative |
|
* consequence of which is wasted space. |
|
* |
|
* This functions returns %0 on success and a negative error code on failure. |
|
*/ |
|
int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key, |
|
int deletion, loff_t new_size) |
|
{ |
|
ino_t inum = key_inum(c, key); |
|
struct size_entry *e; |
|
int err; |
|
|
|
switch (key_type(c, key)) { |
|
case UBIFS_INO_KEY: |
|
if (deletion) |
|
remove_ino(c, inum); |
|
else { |
|
e = find_ino(c, inum); |
|
if (e) { |
|
e->i_size = new_size; |
|
e->exists = 1; |
|
} else { |
|
err = add_ino(c, inum, new_size, 0, 1); |
|
if (err) |
|
return err; |
|
} |
|
} |
|
break; |
|
case UBIFS_DATA_KEY: |
|
e = find_ino(c, inum); |
|
if (e) { |
|
if (new_size > e->d_size) |
|
e->d_size = new_size; |
|
} else { |
|
err = add_ino(c, inum, 0, new_size, 0); |
|
if (err) |
|
return err; |
|
} |
|
break; |
|
case UBIFS_TRUN_KEY: |
|
e = find_ino(c, inum); |
|
if (e) |
|
e->d_size = new_size; |
|
break; |
|
} |
|
return 0; |
|
} |
|
|
|
#ifndef __UBOOT__ |
|
/** |
|
* fix_size_in_place - fix inode size in place on flash. |
|
* @c: UBIFS file-system description object |
|
* @e: inode size information for recovery |
|
*/ |
|
static int fix_size_in_place(struct ubifs_info *c, struct size_entry *e) |
|
{ |
|
struct ubifs_ino_node *ino = c->sbuf; |
|
unsigned char *p; |
|
union ubifs_key key; |
|
int err, lnum, offs, len; |
|
loff_t i_size; |
|
uint32_t crc; |
|
|
|
/* Locate the inode node LEB number and offset */ |
|
ino_key_init(c, &key, e->inum); |
|
err = ubifs_tnc_locate(c, &key, ino, &lnum, &offs); |
|
if (err) |
|
goto out; |
|
/* |
|
* If the size recorded on the inode node is greater than the size that |
|
* was calculated from nodes in the journal then don't change the inode. |
|
*/ |
|
i_size = le64_to_cpu(ino->size); |
|
if (i_size >= e->d_size) |
|
return 0; |
|
/* Read the LEB */ |
|
err = ubifs_leb_read(c, lnum, c->sbuf, 0, c->leb_size, 1); |
|
if (err) |
|
goto out; |
|
/* Change the size field and recalculate the CRC */ |
|
ino = c->sbuf + offs; |
|
ino->size = cpu_to_le64(e->d_size); |
|
len = le32_to_cpu(ino->ch.len); |
|
crc = crc32(UBIFS_CRC32_INIT, (void *)ino + 8, len - 8); |
|
ino->ch.crc = cpu_to_le32(crc); |
|
/* Work out where data in the LEB ends and free space begins */ |
|
p = c->sbuf; |
|
len = c->leb_size - 1; |
|
while (p[len] == 0xff) |
|
len -= 1; |
|
len = ALIGN(len + 1, c->min_io_size); |
|
/* Atomically write the fixed LEB back again */ |
|
err = ubifs_leb_change(c, lnum, c->sbuf, len); |
|
if (err) |
|
goto out; |
|
dbg_rcvry("inode %lu at %d:%d size %lld -> %lld", |
|
(unsigned long)e->inum, lnum, offs, i_size, e->d_size); |
|
return 0; |
|
|
|
out: |
|
ubifs_warn(c, "inode %lu failed to fix size %lld -> %lld error %d", |
|
(unsigned long)e->inum, e->i_size, e->d_size, err); |
|
return err; |
|
} |
|
#endif |
|
|
|
/** |
|
* ubifs_recover_size - recover inode size. |
|
* @c: UBIFS file-system description object |
|
* |
|
* This function attempts to fix inode size discrepancies identified by the |
|
* 'ubifs_recover_size_accum()' function. |
|
* |
|
* This functions returns %0 on success and a negative error code on failure. |
|
*/ |
|
int ubifs_recover_size(struct ubifs_info *c) |
|
{ |
|
struct rb_node *this = rb_first(&c->size_tree); |
|
|
|
while (this) { |
|
struct size_entry *e; |
|
int err; |
|
|
|
e = rb_entry(this, struct size_entry, rb); |
|
if (!e->exists) { |
|
union ubifs_key key; |
|
|
|
ino_key_init(c, &key, e->inum); |
|
err = ubifs_tnc_lookup(c, &key, c->sbuf); |
|
if (err && err != -ENOENT) |
|
return err; |
|
if (err == -ENOENT) { |
|
/* Remove data nodes that have no inode */ |
|
dbg_rcvry("removing ino %lu", |
|
(unsigned long)e->inum); |
|
err = ubifs_tnc_remove_ino(c, e->inum); |
|
if (err) |
|
return err; |
|
} else { |
|
struct ubifs_ino_node *ino = c->sbuf; |
|
|
|
e->exists = 1; |
|
e->i_size = le64_to_cpu(ino->size); |
|
} |
|
} |
|
|
|
if (e->exists && e->i_size < e->d_size) { |
|
if (c->ro_mount) { |
|
/* Fix the inode size and pin it in memory */ |
|
struct inode *inode; |
|
struct ubifs_inode *ui; |
|
|
|
ubifs_assert(!e->inode); |
|
|
|
inode = ubifs_iget(c->vfs_sb, e->inum); |
|
if (IS_ERR(inode)) |
|
return PTR_ERR(inode); |
|
|
|
ui = ubifs_inode(inode); |
|
if (inode->i_size < e->d_size) { |
|
dbg_rcvry("ino %lu size %lld -> %lld", |
|
(unsigned long)e->inum, |
|
inode->i_size, e->d_size); |
|
inode->i_size = e->d_size; |
|
ui->ui_size = e->d_size; |
|
ui->synced_i_size = e->d_size; |
|
e->inode = inode; |
|
this = rb_next(this); |
|
continue; |
|
} |
|
iput(inode); |
|
#ifndef __UBOOT__ |
|
} else { |
|
/* Fix the size in place */ |
|
err = fix_size_in_place(c, e); |
|
if (err) |
|
return err; |
|
if (e->inode) |
|
iput(e->inode); |
|
#endif |
|
} |
|
} |
|
|
|
this = rb_next(this); |
|
rb_erase(&e->rb, &c->size_tree); |
|
kfree(e); |
|
} |
|
|
|
return 0; |
|
}
|
|
|