diff options
Diffstat (limited to 'fs/ubifs/lpt.c')
| -rw-r--r-- | fs/ubifs/lpt.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c index 31393370e334..ed0c67fe7500 100644 --- a/fs/ubifs/lpt.c +++ b/fs/ubifs/lpt.c @@ -1439,6 +1439,38 @@ struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c, } /** + * ubifs_pnode_lookup - lookup a pnode in the LPT. + * @c: UBIFS file-system description object + * @i: pnode number (0 to (main_lebs - 1) / UBIFS_LPT_FANOUT) + * + * This function returns a pointer to the pnode on success or a negative + * error code on failure. + */ +struct ubifs_pnode *ubifs_pnode_lookup(struct ubifs_info *c, int i) +{ + int err, h, iip, shft; + struct ubifs_nnode *nnode; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return ERR_PTR(err); + } + i <<= UBIFS_LPT_FANOUT_SHIFT; + nnode = c->nroot; + 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 = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return ERR_CAST(nnode); + } + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + return ubifs_get_pnode(c, nnode, iip); +} + +/** * ubifs_lpt_lookup - lookup LEB properties in the LPT. * @c: UBIFS file-system description object * @lnum: LEB number to lookup |