Viewing: nodemap_fileset_alt.c
// SPDX-License-Identifier: GPL-2.0
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Author: Marc Vef <mvef@whamcloud.com>
*/
#include <lustre_compat/linux/rbtree.h>
#include <lustre_net.h>
#include "nodemap_internal.h"
/**
* fileset_alt_init() - Allocate lu_fileset_alt struct with a given fileset size
* @fileset_size: size of the fileset path
*
* Returns allocated lu_fileset_alt structure on success, NULL otherwise
*/
struct lu_fileset_alt *fileset_alt_init(unsigned int fileset_size)
{
struct lu_fileset_alt *fileset;
OBD_ALLOC_PTR(fileset);
if (fileset == NULL)
RETURN(NULL);
fileset->nfa_path_size = fileset_size;
fileset->nfa_id = 0; /* is set later on tree insertion */
fileset->nfa_ro = false;
OBD_ALLOC(fileset->nfa_path, fileset->nfa_path_size);
if (fileset->nfa_path == NULL) {
OBD_FREE_PTR(fileset);
RETURN(NULL);
}
return fileset;
}
EXPORT_SYMBOL(fileset_alt_init);
/**
* fileset_alt_create() - Create lu_fileset_alt struct with given fileset path.
* @fileset_path: fileset path
* @read_only: true if the fileset is read-only
*
* Returns allocated lu_fileset_alt structure on success, NULL otherwise
*/
struct lu_fileset_alt *fileset_alt_create(const char *fileset_path,
bool read_only)
{
struct lu_fileset_alt *fileset;
fileset = fileset_alt_init(strlen(fileset_path) + 1);
if (!fileset)
RETURN(NULL);
memcpy(fileset->nfa_path, fileset_path, fileset->nfa_path_size);
fileset->nfa_ro = read_only;
return fileset;
}
EXPORT_SYMBOL(fileset_alt_create);
void fileset_alt_destroy(struct lu_fileset_alt *fileset)
{
OBD_FREE(fileset->nfa_path, fileset->nfa_path_size);
OBD_FREE_PTR(fileset);
}
EXPORT_SYMBOL(fileset_alt_destroy);
void fileset_alt_destroy_tree(struct lu_nodemap *nodemap)
{
struct rb_root *root = &nodemap->nm_fileset_alt;
struct lu_fileset_alt *fileset;
struct lu_fileset_alt *tmp;
rbtree_postorder_for_each_entry_safe(fileset, tmp, root, nfa_rb)
fileset_alt_destroy(fileset);
*root = RB_ROOT;
nodemap->nm_fileset_alt_sz = 0;
}
EXPORT_SYMBOL(fileset_alt_destroy_tree);
/**
* get_first_free_id() - find the first free id in the rb tree on insertion.
* @root: pointer to the root of the rb tree
*
* Helper function to find the first free id in the rb tree on insertion.
*
* Return first free id found on success
*/
static unsigned int get_first_free_id(struct rb_root *root)
{
struct rb_node *node;
struct lu_fileset_alt *fileset;
/* start at 1. 0 is reserved for the prim fileset in another context */
unsigned int fset_id = 1;
/* iterate over the tree and find gaps in the id sequence */
for (node = rb_first(root); node; node = rb_next(node)) {
fileset = rb_entry(node, struct lu_fileset_alt, nfa_rb);
if (fileset->nfa_id != fset_id)
RETURN(fset_id);
fset_id++;
}
/* no gaps found, return the next id after the last one in the tree */
return fset_id;
}
/**
* fileset_alt_add() - Insert an alt fileset into a nodemap
*
* @nodemap: pointer to the nodemap
* @fileset: fileset to insert
*
* If fileset->nfa_id is 0, the first free id is assigned and used. The caller
* is free to set its own fileset->nfa_id as long as it is not 0.
*
* Return:
* * %0 on success
* * %-EEXIST if the fileset id already exists
* * %-ENOSPC if the fileset id exceeds LUSTRE_NODEMAP_FILESET_NUM_MAX
*/
int fileset_alt_add(struct lu_nodemap *nodemap, struct lu_fileset_alt *fileset)
{
struct rb_root *root = &nodemap->nm_fileset_alt;
struct rb_node **new = &(root->rb_node);
struct rb_node *parent = NULL;
struct lu_fileset_alt *this = NULL;
if (fileset->nfa_id == 0)
fileset->nfa_id = get_first_free_id(root);
if (fileset->nfa_id > LUSTRE_NODEMAP_FILESET_NUM_MAX - 1)
return -ENOSPC;
/* determine the correct position in the tree */
while (*new) {
this = rb_entry(*new, struct lu_fileset_alt, nfa_rb);
parent = *new;
if (fileset->nfa_id < this->nfa_id)
new = &((*new)->rb_left);
else if (fileset->nfa_id > this->nfa_id)
new = &((*new)->rb_right);
else
return -EEXIST;
}
/* insert the new node and rebalance tree */
rb_link_node(&fileset->nfa_rb, parent, new);
rb_insert_color(&fileset->nfa_rb, root);
nodemap->nm_fileset_alt_sz++;
return 0;
}
EXPORT_SYMBOL(fileset_alt_add);
/**
* fileset_alt_delete() - Delete an alt fileset from a nodemap
*
* @nodemap: pointer to the nodemap
* @fileset: fileset to delete
*
* Return:
* * %0 id of the deleted fileset
* * %-EINVAL fileset is NULL
*/
int fileset_alt_delete(struct lu_nodemap *nodemap,
struct lu_fileset_alt *fileset)
{
struct rb_root *root = &nodemap->nm_fileset_alt;
unsigned int fset_id;
if (fileset == NULL)
return -EINVAL;
fset_id = fileset->nfa_id;
rb_erase(&fileset->nfa_rb, root);
nodemap->nm_fileset_alt_sz--;
fileset_alt_destroy(fileset);
return fset_id;
}
EXPORT_SYMBOL(fileset_alt_delete);
static int compare_by_id(const void *key, const struct rb_node *node)
{
const int *search_id;
struct lu_fileset_alt *fileset;
int rc;
search_id = key;
fileset = rb_entry(node, struct lu_fileset_alt, nfa_rb);
if (*search_id < fileset->nfa_id)
rc = -1;
else if (*search_id > fileset->nfa_id)
rc = 1;
else
rc = 0;
return rc;
}
/**
* fileset_alt_search_id() - Search for a fileset by its fileset id.
* @root: pointer to the root of the rb tree
* @fileset_id: id of the fileset to search
*
* Returns lu_fileset_alt structure on success, NULL otherwise
*/
struct lu_fileset_alt *fileset_alt_search_id(struct rb_root *root,
unsigned int fileset_id)
{
struct lu_fileset_alt *fileset = NULL;
struct rb_node *node;
node = rb_find(&fileset_id, root, compare_by_id);
if (node)
fileset = rb_entry(node, struct lu_fileset_alt, nfa_rb);
return fileset;
}
EXPORT_SYMBOL(fileset_alt_search_id);
/**
* fileset_alt_search_path() - Search for a fileset by its fileset path.
* @root: pointer to the root of the rb tree
* @fileset_path: path of the fileset to search
* @prefix_search: search for a fileset that is the closest prefix to
* fileset_path rather than an exact match
*
* Return lu_fileset_alt structure on success, NULL otherwise
*/
struct lu_fileset_alt *fileset_alt_search_path(struct rb_root *root,
const char *fileset_path,
bool prefix_search)
{
struct rb_node *node;
struct lu_fileset_alt *tmp;
struct lu_fileset_alt *fileset = NULL;
size_t fileset_len = 0;
size_t tmp_len;
int rc;
/* search the full tree for a fileset with the given path */
for (node = rb_first(root); node; node = rb_next(node)) {
tmp = rb_entry(node, struct lu_fileset_alt, nfa_rb);
if (prefix_search) {
/* accepted (rc = 0) if fileset_path starts like alt
* fileset, and is followed by '/' (subdirectory)
* or '\0' (identical)
*/
rc = (strstr(fileset_path, tmp->nfa_path) !=
fileset_path ||
(fileset_path[strlen(tmp->nfa_path)] != '/' &&
fileset_path[strlen(tmp->nfa_path)] != '\0'));
if (!rc) {
tmp_len = strlen(tmp->nfa_path);
if (tmp_len > fileset_len) {
fileset = tmp;
fileset_len = tmp_len;
}
}
} else {
rc = strcmp(fileset_path, tmp->nfa_path);
if (!rc) {
fileset = tmp;
break;
}
}
}
return fileset;
}
EXPORT_SYMBOL(fileset_alt_search_path);
bool fileset_alt_path_exists(struct rb_root *root, const char *path)
{
return fileset_alt_search_path(root, path, false) != NULL;
}
EXPORT_SYMBOL(fileset_alt_path_exists);
/**
* fileset_alt_resize() - Resize fileset to the actual needed size
* @root: pointer to the root of the rb tree
*
* Iterate over all rb tree entries and shrink the memory requirements
* for the fileset to the actual needed size. This is required when the
* fileset fragments are read from the nodemap IAM, and so the preallocated
* size may be larger than needed.
*/
void fileset_alt_resize(struct rb_root *root)
{
struct rb_node *node;
struct lu_fileset_alt *fileset;
unsigned int fset_size_actual, fset_size_prealloc;
char *fset_tmp;
for (node = rb_first(root); node; node = rb_next(node)) {
fileset = rb_entry(node, struct lu_fileset_alt, nfa_rb);
fset_size_prealloc = fileset->nfa_path_size;
fset_size_actual = strlen(fileset->nfa_path) + 1;
if (fset_size_actual == fset_size_prealloc)
continue;
/* Shrink fileset size to actual */
OBD_ALLOC(fset_tmp, fset_size_actual);
if (!fset_tmp) {
CERROR("%s: Nodemaps's fileset cannot be resized: rc = %d\n",
fileset->nfa_path, -ENOMEM);
continue;
}
memcpy(fset_tmp, fileset->nfa_path, fset_size_actual);
OBD_FREE(fileset->nfa_path, fset_size_prealloc);
fileset->nfa_path = fset_tmp;
fileset->nfa_path_size = fset_size_actual;
}
}
EXPORT_SYMBOL(fileset_alt_resize);
