[PATCH 22/27] ubifs: lpt: implement functions to scan lpt
Dongsheng Yang
yangds.fnst at cn.fujitsu.com
Wed Aug 19 01:39:27 PDT 2015
Implement ubifs_scan_lpt_nolock() in lpt to scan lpt.
And then we can use this function to scan the lpt
and dump all lprops out.
Signed-off-by: Dongsheng Yang <yangds.fnst at cn.fujitsu.com>
---
ubifs-utils/include/lpt.h | 3 +
ubifs-utils/lib/lpt.c | 661 +++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 663 insertions(+), 1 deletion(-)
diff --git a/ubifs-utils/include/lpt.h b/ubifs-utils/include/lpt.h
index e2f7348..d4264c3 100644
--- a/ubifs-utils/include/lpt.h
+++ b/ubifs-utils/include/lpt.h
@@ -25,5 +25,8 @@
int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs, int *big_lpt);
int create_lpt(struct ubifs_info *c);
int ubifs_calc_lpt_geom(struct ubifs_info *c);
+int unpack_ltab(const struct ubifs_info *c, void *buf);
+int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
+ ubifs_lpt_scan_callback scan_cb, void *data);
#endif
diff --git a/ubifs-utils/lib/lpt.c b/ubifs-utils/lib/lpt.c
index 26fb4dd..52fbcfa 100644
--- a/ubifs-utils/lib/lpt.c
+++ b/ubifs-utils/lib/lpt.c
@@ -29,6 +29,7 @@
#include "crc16.h"
#include "ubifs.h"
#include "lpt.h"
+#include "lprops.h"
#include "io.h"
/**
@@ -402,7 +403,6 @@ int create_lpt(struct ubifs_info *c)
len = 0;
/* Number of leaf nodes (pnodes) */
cnt = (c->main_lebs + UBIFS_LPT_FANOUT - 1) >> UBIFS_LPT_FANOUT_SHIFT;
- //printf("pnode_cnt=%d\n",cnt);
/*
* To calculate the internal node branches, we keep information about
@@ -614,3 +614,662 @@ int ubifs_calc_lpt_geom(struct ubifs_info *c)
}
return 0;
}
+
+/**
+ * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
+ * @nnode: where to keep a nnode
+ * @pnode: where to keep a pnode
+ * @cnode: where to keep a cnode
+ * @in_tree: is the node in the tree in memory
+ * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
+ * the tree
+ * @ptr.pnode: ditto for pnode
+ * @ptr.cnode: ditto for cnode
+ */
+struct lpt_scan_node {
+ union {
+ struct ubifs_nnode nnode;
+ struct ubifs_pnode pnode;
+ struct ubifs_cnode cnode;
+ };
+ int in_tree;
+ union {
+ struct ubifs_nnode *nnode;
+ struct ubifs_pnode *pnode;
+ struct ubifs_cnode *cnode;
+ } ptr;
+};
+
+/**
+ * ubifs_unpack_bits - unpack bit fields.
+ * @addr: address at which to unpack (passed and next address returned)
+ * @pos: bit position at which to unpack (passed and next position returned)
+ * @nrbits: number of bits of value to unpack (1-32)
+ *
+ * This functions returns the value unpacked.
+ */
+uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits)
+{
+ const int k = 32 - nrbits;
+ uint8_t *p = *addr;
+ int b = *pos;
+ uint32_t val = 0;
+ const int bytes = (nrbits + b + 7) >> 3;
+
+ ubifs_assert(nrbits > 0);
+ ubifs_assert(nrbits <= 32);
+ ubifs_assert(*pos >= 0);
+ ubifs_assert(*pos < 8);
+ if (b) {
+ switch (bytes) {
+ case 2:
+ val = p[1];
+ break;
+ case 3:
+ val = p[1] | ((uint32_t)p[2] << 8);
+ break;
+ case 4:
+ val = p[1] | ((uint32_t)p[2] << 8) |
+ ((uint32_t)p[3] << 16);
+ break;
+ case 5:
+ val = p[1] | ((uint32_t)p[2] << 8) |
+ ((uint32_t)p[3] << 16) |
+ ((uint32_t)p[4] << 24);
+ }
+ val <<= (8 - b);
+ val |= *p >> b;
+ nrbits += b;
+ } else {
+ switch (bytes) {
+ case 1:
+ val = p[0];
+ break;
+ case 2:
+ val = p[0] | ((uint32_t)p[1] << 8);
+ break;
+ case 3:
+ val = p[0] | ((uint32_t)p[1] << 8) |
+ ((uint32_t)p[2] << 16);
+ break;
+ case 4:
+ val = p[0] | ((uint32_t)p[1] << 8) |
+ ((uint32_t)p[2] << 16) |
+ ((uint32_t)p[3] << 24);
+ break;
+ }
+ }
+ val <<= k;
+ val >>= k;
+ b = nrbits & 7;
+ p += nrbits >> 3;
+ *addr = p;
+ *pos = b;
+ ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32);
+ return val;
+}
+/**
+ * calc_nnode_num_from_parent - calculate nnode number.
+ * @c: UBIFS file-system description object
+ * @parent: parent nnode
+ * @iip: index in parent
+ *
+ * The nnode number is a number that uniquely identifies a nnode and can be used
+ * easily to traverse the tree from the root to that nnode.
+ *
+ * This function calculates and returns the nnode number based on the parent's
+ * nnode number and the index in parent.
+ */
+static int calc_nnode_num_from_parent(const struct ubifs_info *c,
+ struct ubifs_nnode *parent, int iip)
+{
+ int num, shft;
+
+ if (!parent)
+ return 1;
+ shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
+ num = parent->num ^ (1 << shft);
+ num |= (UBIFS_LPT_FANOUT + iip) << shft;
+ return num;
+}
+
+int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
+ struct ubifs_nnode *nnode);
+/**
+ * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
+ * @c: the UBIFS file-system description object
+ * @path: where to put the nnode
+ * @parent: parent of the nnode
+ * @iip: index in parent of the nnode
+ *
+ * This function returns a pointer to the nnode on success or a negative error
+ * code on failure.
+ */
+static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
+ struct lpt_scan_node *path,
+ struct ubifs_nnode *parent, int iip)
+{
+ struct ubifs_nbranch *branch;
+ struct ubifs_nnode *nnode;
+ int i = max_t(int, c->nnode_sz, c->pnode_sz);
+ void *buf = malloc(i);;
+ int err;
+
+ branch = &parent->nbranch[iip];
+ nnode = branch->nnode;
+ if (nnode) {
+ path->in_tree = 1;
+ path->ptr.nnode = nnode;
+ free(buf);
+ return nnode;
+ }
+ nnode = &path->nnode;
+ path->in_tree = 0;
+ path->ptr.nnode = nnode;
+ memset(nnode, 0, sizeof(struct ubifs_nnode));
+ if (branch->lnum == 0) {
+ /*
+ * This nnode was not written which just means that the LEB
+ * properties in the subtree below it describe empty LEBs. We
+ * make the nnode as though we had read it, which in fact means
+ * doing almost nothing.
+ */
+ if (c->big_lpt)
+ nnode->num = calc_nnode_num_from_parent(c, parent, iip);
+ } else {
+ err = ubifs_read(branch->lnum * c->leb_size + branch->offs, c->nnode_sz, buf);
+ if (err) {
+ free(buf);
+ return ERR_PTR(err);
+ }
+ err = ubifs_unpack_nnode(c, buf, nnode);
+ if (err) {
+ free(buf);
+ return ERR_PTR(err);
+ }
+ }
+ if (!c->big_lpt)
+ nnode->num = calc_nnode_num_from_parent(c, parent, iip);
+ nnode->level = parent->level - 1;
+ nnode->parent = parent;
+ nnode->iip = iip;
+
+ free(buf);
+ return nnode;
+}
+/**
+ * calc_pnode_num_from_parent - calculate pnode number.
+ * @c: UBIFS file-system description object
+ * @parent: parent nnode
+ * @iip: index in parent
+ *
+ * The pnode number is a number that uniquely identifies a pnode and can be used
+ * easily to traverse the tree from the root to that pnode.
+ *
+ * This function calculates and returns the pnode number based on the parent's
+ * nnode number and the index in parent.
+ */
+static int calc_pnode_num_from_parent(const struct ubifs_info *c,
+ struct ubifs_nnode *parent, int iip)
+{
+ int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
+
+ for (i = 0; i < n; i++) {
+ num <<= UBIFS_LPT_FANOUT_SHIFT;
+ num |= pnum & (UBIFS_LPT_FANOUT - 1);
+ pnum >>= UBIFS_LPT_FANOUT_SHIFT;
+ }
+ num <<= UBIFS_LPT_FANOUT_SHIFT;
+ num |= iip;
+ return num;
+}
+/**
+ * set_pnode_lnum - set LEB numbers on a pnode.
+ * @c: UBIFS file-system description object
+ * @pnode: pnode to update
+ *
+ * This function calculates the LEB numbers for the LEB properties it contains
+ * based on the pnode number.
+ */
+static void set_pnode_lnum(const struct ubifs_info *c,
+ struct ubifs_pnode *pnode)
+{
+ int i, lnum;
+
+ lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ if (lnum >= c->leb_cnt)
+ return;
+ pnode->lprops[i].lnum = lnum++;
+ }
+}
+/**
+ * check_lpt_crc - check LPT node crc is correct.
+ * @c: UBIFS file-system description object
+ * @buf: buffer containing node
+ * @len: length of node
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int check_lpt_crc(const struct ubifs_info *c __attribute__((unused)), void *buf, int len)
+{
+ int pos = 0;
+ uint8_t *addr = buf;
+ uint16_t crc, calc_crc;
+
+ crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
+ calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
+ len - UBIFS_LPT_CRC_BYTES);
+ if (crc != calc_crc) {
+ ubifs_err(c, "invalid crc in LPT node: crc %hx calc %hx",
+ crc, calc_crc);
+ return -EINVAL;
+ }
+ return 0;
+}
+/**
+ * check_lpt_type - check LPT node type is correct.
+ * @c: UBIFS file-system description object
+ * @addr: address of type bit field is passed and returned updated here
+ * @pos: position of type bit field is passed and returned updated here
+ * @type: expected type
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int check_lpt_type(const struct ubifs_info *c __attribute__((unused)), uint8_t **addr,
+ int *pos, int type)
+{
+ int node_type;
+
+ node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
+ if (node_type != type) {
+ ubifs_err(c, "invalid type (%d) in LPT node type %d",
+ node_type, type);
+ return -EINVAL;
+ }
+ return 0;
+}
+/**
+ * unpack_pnode - unpack a pnode.
+ * @c: UBIFS file-system description object
+ * @buf: buffer containing packed pnode to unpack
+ * @pnode: pnode structure to fill
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int unpack_pnode(const struct ubifs_info *c, void *buf,
+ struct ubifs_pnode *pnode)
+{
+ uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
+ int i, pos = 0, err;
+
+ err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_PNODE);
+ if (err)
+ return err;
+ if (c->big_lpt)
+ pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ struct ubifs_lprops * const lprops = &pnode->lprops[i];
+
+ lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
+ lprops->free <<= 3;
+ lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
+ lprops->dirty <<= 3;
+
+ if (ubifs_unpack_bits(&addr, &pos, 1))
+ lprops->flags = LPROPS_INDEX;
+ else
+ lprops->flags = 0;
+ lprops->flags |= ubifs_categorize_lprops(c, lprops);
+ }
+ err = check_lpt_crc(c, buf, c->pnode_sz);
+ return err;
+}
+/**
+ * ubifs_unpack_nnode - unpack a nnode.
+ * @c: UBIFS file-system description object
+ * @buf: buffer containing packed nnode to unpack
+ * @nnode: nnode structure to fill
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
+ struct ubifs_nnode *nnode)
+{
+ uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
+ int i, pos = 0, err;
+
+ err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_NNODE);
+ if (err)
+ return err;
+ if (c->big_lpt)
+ nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ int lnum;
+
+ lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
+ c->lpt_first;
+ if (lnum == c->lpt_last + 1)
+ lnum = 0;
+ nnode->nbranch[i].lnum = lnum;
+ nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
+ c->lpt_offs_bits);
+ }
+ err = check_lpt_crc(c, buf, c->nnode_sz);
+ return err;
+}
+/**
+ * unpack_ltab - unpack the LPT's own lprops table.
+ * @c: UBIFS file-system description object
+ * @buf: buffer from which to unpack
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int unpack_ltab(const struct ubifs_info *c, void *buf)
+{
+ uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
+ int i, pos = 0, err;
+
+ err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LTAB);
+ if (err)
+ return err;
+ for (i = 0; i < c->lpt_lebs; i++) {
+ int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
+ int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
+
+ if (free < 0 || free > c->leb_size || dirty < 0 ||
+ dirty > c->leb_size || free + dirty > c->leb_size)
+ return -EINVAL;
+
+ c->ltab[i].free = free;
+ c->ltab[i].dirty = dirty;
+ c->ltab[i].tgc = 0;
+ c->ltab[i].cmt = 0;
+ }
+ return 0;
+}
+
+/**
+ * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
+ * @c: the UBIFS file-system description object
+ * @path: where to put the pnode
+ * @parent: parent of the pnode
+ * @iip: index in parent of the pnode
+ *
+ * This function returns a pointer to the pnode on success or a negative error
+ * code on failure.
+ */
+static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
+ struct lpt_scan_node *path,
+ struct ubifs_nnode *parent, int iip)
+{
+ struct ubifs_nbranch *branch;
+ struct ubifs_pnode *pnode;
+ int i = max_t(int, c->nnode_sz, c->pnode_sz);
+ void *buf = malloc(i);;
+ int err;
+
+ branch = &parent->nbranch[iip];
+ pnode = branch->pnode;
+ if (pnode) {
+ path->in_tree = 1;
+ path->ptr.pnode = pnode;
+ free(buf);
+ return pnode;
+ }
+ pnode = &path->pnode;
+ path->in_tree = 0;
+ path->ptr.pnode = pnode;
+ memset(pnode, 0, sizeof(struct ubifs_pnode));
+ if (branch->lnum == 0) {
+ /*
+ * This pnode was not written which just means that the LEB
+ * properties in it describe empty LEBs. We make the pnode as
+ * though we had read it.
+ */
+ int i;
+
+ if (c->big_lpt)
+ pnode->num = calc_pnode_num_from_parent(c, parent, iip);
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ struct ubifs_lprops * const lprops = &pnode->lprops[i];
+
+ lprops->free = c->leb_size;
+ lprops->flags = ubifs_categorize_lprops(c, lprops);
+ }
+ } else {
+ ubifs_assert(branch->lnum >= c->lpt_first &&
+ branch->lnum <= c->lpt_last);
+ ubifs_assert(branch->offs >= 0 && branch->offs < c->leb_size);
+ err = ubifs_read(branch->lnum * c->leb_size + branch->offs, c->pnode_sz, buf);
+ if (err) {
+ free(buf);
+ return ERR_PTR(err);
+ }
+ err = unpack_pnode(c, buf, pnode);
+ if (err) {
+ free(buf);
+ return ERR_PTR(err);
+ }
+ }
+ if (!c->big_lpt)
+ pnode->num = calc_pnode_num_from_parent(c, parent, iip);
+ pnode->parent = parent;
+ pnode->iip = iip;
+ set_pnode_lnum(c, pnode);
+ free(buf);
+ return pnode;
+}
+/**
+ * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
+ * @c: UBIFS file-system description object
+ * @parent: parent nnode (or NULL for the root)
+ * @iip: index in parent
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
+{
+ struct ubifs_nbranch *branch = NULL;
+ struct ubifs_nnode *nnode = NULL;
+ void *buf = c->lpt_nod_buf;
+ int err, lnum, offs;
+
+ if (parent) {
+ branch = &parent->nbranch[iip];
+ lnum = branch->lnum;
+ offs = branch->offs;
+ } else {
+ lnum = c->lpt_lnum;
+ offs = c->lpt_offs;
+ }
+ nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
+ if (!nnode) {
+ err = -ENOMEM;
+ goto out;
+ }
+ if (lnum == 0) {
+ /*
+ * This nnode was not written which just means that the LEB
+ * properties in the subtree below it describe empty LEBs. We
+ * make the nnode as though we had read it, which in fact means
+ * doing almost nothing.
+ */
+ if (c->big_lpt)
+ nnode->num = calc_nnode_num_from_parent(c, parent, iip);
+ } else {
+ err = ubifs_read(lnum * c->leb_size + offs, c->nnode_sz, buf);
+ if (err)
+ goto out;
+ err = ubifs_unpack_nnode(c, buf, nnode);
+ if (err)
+ goto out;
+ }
+ if (!c->big_lpt)
+ nnode->num = calc_nnode_num_from_parent(c, parent, iip);
+ if (parent) {
+ branch->nnode = nnode;
+ nnode->level = parent->level - 1;
+ } else {
+ c->nroot = nnode;
+ nnode->level = c->lpt_hght;
+ }
+ nnode->parent = parent;
+ nnode->iip = iip;
+ return 0;
+
+out:
+ ubifs_err(c, "error %d reading nnode at %d:%d", err, lnum, offs);
+ kfree(nnode);
+ return err;
+}
+
+/**
+ * ubifs_lpt_scan_nolock - scan the LPT.
+ * @c: the UBIFS file-system description object
+ * @start_lnum: LEB number from which to start scanning
+ * @end_lnum: LEB number at which to stop scanning
+ * @scan_cb: callback function called for each lprops
+ * @data: data to be passed to the callback function
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
+ ubifs_lpt_scan_callback scan_cb, void *data)
+{
+ int err = 0, i, h, iip, shft;
+ struct ubifs_nnode *nnode;
+ struct ubifs_pnode *pnode;
+ struct lpt_scan_node *path;
+
+ if (start_lnum == -1) {
+ start_lnum = end_lnum + 1;
+ if (start_lnum >= c->leb_cnt)
+ start_lnum = c->main_first;
+ }
+
+ ubifs_assert(start_lnum >= c->main_first && start_lnum < c->leb_cnt);
+ ubifs_assert(end_lnum >= c->main_first && end_lnum < c->leb_cnt);
+
+ if (!c->nroot) {
+ err = ubifs_read_nnode(c, NULL, 0);
+ if (err)
+ return err;
+ }
+
+ path = kmalloc(sizeof(struct lpt_scan_node) * (c->lpt_hght + 1),
+ GFP_NOFS);
+ if (!path)
+ return -ENOMEM;
+
+ path[0].ptr.nnode = c->nroot;
+ path[0].in_tree = 1;
+again:
+ /* Descend to the pnode containing start_lnum */
+ nnode = c->nroot;
+ i = start_lnum - c->main_first;
+ shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
+ for (h = 1; h < c->lpt_hght; h++) {
+ iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
+ shft -= UBIFS_LPT_FANOUT_SHIFT;
+ nnode = scan_get_nnode(c, path + h, nnode, iip);
+ if (IS_ERR(nnode)) {
+ err = PTR_ERR(nnode);
+ goto out;
+ }
+ }
+ iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
+ pnode = scan_get_pnode(c, path + h, nnode, iip);
+ if (IS_ERR(pnode)) {
+ err = PTR_ERR(pnode);
+ goto out;
+ }
+ iip = (i & (UBIFS_LPT_FANOUT - 1));
+
+ /* Loop for each lprops */
+ while (1) {
+ struct ubifs_lprops *lprops = &pnode->lprops[iip];
+ int ret, lnum = lprops->lnum;
+
+ ret = scan_cb(c, lprops, path[h].in_tree, data);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ if (ret & LPT_SCAN_ADD) {
+ /* Add all the nodes in path to the tree in memory */
+ for (h = 1; h < c->lpt_hght; h++) {
+ const size_t sz = sizeof(struct ubifs_nnode);
+ struct ubifs_nnode *parent;
+
+ if (path[h].in_tree)
+ continue;
+ nnode = malloc(sz);
+ if (!nnode) {
+ err = -ENOMEM;
+ goto out;
+ }
+ memcpy(nnode, &path[h].nnode, sz);
+ parent = nnode->parent;
+ parent->nbranch[nnode->iip].nnode = nnode;
+ path[h].ptr.nnode = nnode;
+ path[h].in_tree = 1;
+ path[h + 1].cnode.parent = nnode;
+ }
+ }
+ if (ret & LPT_SCAN_STOP) {
+ err = 0;
+ break;
+ }
+ /* Get the next lprops */
+ if (lnum == end_lnum) {
+ /*
+ * We got to the end without finding what we were
+ * looking for
+ */
+ err = -ENOSPC;
+ goto out;
+ }
+ if (lnum + 1 >= c->leb_cnt) {
+ /* Wrap-around to the beginning */
+ start_lnum = c->main_first;
+ goto again;
+ }
+ if (iip + 1 < UBIFS_LPT_FANOUT) {
+ /* Next lprops is in the same pnode */
+ iip += 1;
+ continue;
+ }
+ /* We need to get the next pnode. Go up until we can go right */
+ iip = pnode->iip;
+ while (1) {
+ h -= 1;
+ ubifs_assert(h >= 0);
+ nnode = path[h].ptr.nnode;
+ if (iip + 1 < UBIFS_LPT_FANOUT)
+ break;
+ iip = nnode->iip;
+ }
+ /* Go right */
+ iip += 1;
+ /* Descend to the pnode */
+ h += 1;
+ for (; h < c->lpt_hght; h++) {
+ nnode = scan_get_nnode(c, path + h, nnode, iip);
+ if (IS_ERR(nnode)) {
+ err = PTR_ERR(nnode);
+ goto out;
+ }
+ iip = 0;
+ }
+ pnode = scan_get_pnode(c, path + h, nnode, iip);
+ if (IS_ERR(pnode)) {
+ err = PTR_ERR(pnode);
+ goto out;
+ }
+ iip = 0;
+ }
+out:
+ kfree(path);
+ return err;
+}
--
1.8.4.2
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