+++ /dev/null
-// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
-// vim: ts=8 sw=2 smarttab
-
-#include "chain_xattr.h"
-#include <errno.h> // for ERANGE, ENODATA, ENOMEM
-#include <stdio.h> // for size_t, snprintf
-#include <stdlib.h> // for free, malloc
-#include <string.h> // for strcpy, strlen
-#include "include/assert.h" // for assert
-#include "include/buffer.h"
-
-#if defined(__linux__)
-#include <linux/fs.h>
-#endif
-
-/*
- * chaining xattrs
- *
- * In order to support xattrs that are larger than the xattr size limit that some file systems
- * impose, we use multiple xattrs to store the value of a single xattr. The xattrs keys
- * are set as follows:
- * The first xattr in the chain, has a key that holds the original xattr name, with any '@' char
- * being esacped ("@@").
- * The chained keys will have the first xattr's key (with the escaping), and a suffix: "@<id>"
- * where <id> marks the num of xattr in the chain.
- */
-
-void get_raw_xattr_name(const char *name, int i, char *raw_name, int raw_len)
-{
- int pos = 0;
-
- while (*name) {
- switch (*name) {
- case '@': /* escape it */
- pos += 2;
- assert (pos < raw_len - 1);
- *raw_name = '@';
- raw_name++;
- *raw_name = '@';
- break;
- default:
- pos++;
- assert(pos < raw_len - 1);
- *raw_name = *name;
- break;
- }
- name++;
- raw_name++;
- }
-
- if (!i) {
- *raw_name = '\0';
- } else {
- int r = snprintf(raw_name, raw_len - pos, "@%d", i);
- assert(r < raw_len - pos);
- }
-}
-
-static int translate_raw_name(const char *raw_name, char *name, int name_len, bool *is_first)
-{
- int pos = 0;
-
- *is_first = true;
- while (*raw_name) {
- switch (*raw_name) {
- case '@': /* escape it */
- raw_name++;
- if (!*raw_name)
- break;
- if (*raw_name != '@') {
- *is_first = false;
- goto done;
- }
-
- /* fall through */
- default:
- *name = *raw_name;
- break;
- }
- pos++;
- assert(pos < name_len);
- name++;
- raw_name++;
- }
-done:
- *name = '\0';
- return pos;
-}
-
-
-// setxattr
-
-static int getxattr_len(const char *fn, const char *name)
-{
- int i = 0, total = 0;
- char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int r;
-
- do {
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
- r = sys_getxattr(fn, raw_name, 0, 0);
- if (!i && r < 0)
- return r;
- if (r < 0)
- break;
- total += r;
- i++;
- } while (r == CHAIN_XATTR_MAX_BLOCK_LEN ||
- r == CHAIN_XATTR_SHORT_BLOCK_LEN);
-
- return total;
-}
-
-int chain_getxattr(const char *fn, const char *name, void *val, size_t size)
-{
- int i = 0, pos = 0;
- char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int ret = 0;
- int r;
- size_t chunk_size;
-
- if (!size)
- return getxattr_len(fn, name);
-
- do {
- chunk_size = size;
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
-
- r = sys_getxattr(fn, raw_name, (char *)val + pos, chunk_size);
- if (i && r == -ENODATA) {
- ret = pos;
- break;
- }
- if (r < 0) {
- ret = r;
- break;
- }
-
- if (r > 0) {
- pos += r;
- size -= r;
- }
-
- i++;
- } while (size && (r == CHAIN_XATTR_MAX_BLOCK_LEN ||
- r == CHAIN_XATTR_SHORT_BLOCK_LEN));
-
- if (r >= 0) {
- ret = pos;
- /* is there another chunk? that can happen if the last read size span over
- exactly one block */
- if (chunk_size == CHAIN_XATTR_MAX_BLOCK_LEN ||
- chunk_size == CHAIN_XATTR_SHORT_BLOCK_LEN) {
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
- r = sys_getxattr(fn, raw_name, 0, 0);
- if (r > 0) { // there's another chunk.. the original buffer was too small
- ret = -ERANGE;
- }
- }
- }
- return ret;
-}
-
-int chain_getxattr_buf(const char *fn, const char *name, bufferptr *bp)
-{
- size_t size = 1024; // Initial
- while (1) {
- bufferptr buf(size);
- int r = chain_getxattr(
- fn,
- name,
- buf.c_str(),
- size);
- if (r > 0) {
- buf.set_length(r);
- if (bp)
- bp->swap(buf);
- return r;
- } else if (r == 0) {
- return 0;
- } else {
- if (r == -ERANGE) {
- size *= 2;
- } else {
- return r;
- }
- }
- }
- assert(0 == "unreachable");
- return 0;
-}
-
-static int chain_fgetxattr_len(int fd, const char *name)
-{
- int i = 0, total = 0;
- char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int r;
-
- do {
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
- r = sys_fgetxattr(fd, raw_name, 0, 0);
- if (!i && r < 0)
- return r;
- if (r < 0)
- break;
- total += r;
- i++;
- } while (r == CHAIN_XATTR_MAX_BLOCK_LEN ||
- r == CHAIN_XATTR_SHORT_BLOCK_LEN);
-
- return total;
-}
-
-int chain_fgetxattr(int fd, const char *name, void *val, size_t size)
-{
- int i = 0, pos = 0;
- char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int ret = 0;
- int r;
- size_t chunk_size;
-
- if (!size)
- return chain_fgetxattr_len(fd, name);
-
- do {
- chunk_size = size;
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
-
- r = sys_fgetxattr(fd, raw_name, (char *)val + pos, chunk_size);
- if (i && r == -ENODATA) {
- ret = pos;
- break;
- }
- if (r < 0) {
- ret = r;
- break;
- }
-
- if (r > 0) {
- pos += r;
- size -= r;
- }
-
- i++;
- } while (size && (r == CHAIN_XATTR_MAX_BLOCK_LEN ||
- r == CHAIN_XATTR_SHORT_BLOCK_LEN));
-
- if (r >= 0) {
- ret = pos;
- /* is there another chunk? that can happen if the last read size span over
- exactly one block */
- if (chunk_size == CHAIN_XATTR_MAX_BLOCK_LEN ||
- chunk_size == CHAIN_XATTR_SHORT_BLOCK_LEN) {
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
- r = sys_fgetxattr(fd, raw_name, 0, 0);
- if (r > 0) { // there's another chunk.. the original buffer was too small
- ret = -ERANGE;
- }
- }
- }
- return ret;
-}
-
-
-// setxattr
-
-int get_xattr_block_size(size_t size)
-{
- if (size <= CHAIN_XATTR_SHORT_LEN_THRESHOLD)
- // this may fit in the inode; stripe over short attrs so that XFS
- // won't kick it out.
- return CHAIN_XATTR_SHORT_BLOCK_LEN;
- return CHAIN_XATTR_MAX_BLOCK_LEN;
-}
-
-// removexattr
-
-int chain_removexattr(const char *fn, const char *name)
-{
- int i = 0;
- char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int r;
-
- do {
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
- r = sys_removexattr(fn, raw_name);
- if (!i && r < 0) {
- return r;
- }
- i++;
- } while (r >= 0);
- return 0;
-}
-
-int chain_fremovexattr(int fd, const char *name)
-{
- int i = 0;
- char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int r;
-
- do {
- get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
- r = sys_fremovexattr(fd, raw_name);
- if (!i && r < 0) {
- return r;
- }
- i++;
- } while (r >= 0);
- return 0;
-}
-
-
-// listxattr
-
-int chain_listxattr(const char *fn, char *names, size_t len) {
- int r;
-
- if (!len)
- return sys_listxattr(fn, names, len) * 2;
-
- r = sys_listxattr(fn, 0, 0);
- if (r < 0)
- return r;
-
- size_t total_len = r * 2; // should be enough
- char *full_buf = (char *)malloc(total_len);
- if (!full_buf)
- return -ENOMEM;
-
- r = sys_listxattr(fn, full_buf, total_len);
- if (r < 0) {
- free(full_buf);
- return r;
- }
-
- char *p = full_buf;
- const char *end = full_buf + r;
- char *dest = names;
- char *dest_end = names + len;
-
- while (p < end) {
- char name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int attr_len = strlen(p);
- bool is_first;
- int name_len = translate_raw_name(p, name, sizeof(name), &is_first);
- if (is_first) {
- if (dest + name_len > dest_end) {
- r = -ERANGE;
- goto done;
- }
- strcpy(dest, name);
- dest += name_len + 1;
- }
- p += attr_len + 1;
- }
- r = dest - names;
-
-done:
- free(full_buf);
- return r;
-}
-
-int chain_flistxattr(int fd, char *names, size_t len) {
- int r;
- char *p;
- const char * end;
- char *dest;
- char *dest_end;
-
- if (!len)
- return sys_flistxattr(fd, names, len) * 2;
-
- r = sys_flistxattr(fd, 0, 0);
- if (r < 0)
- return r;
-
- size_t total_len = r * 2; // should be enough
- char *full_buf = (char *)malloc(total_len);
- if (!full_buf)
- return -ENOMEM;
-
- r = sys_flistxattr(fd, full_buf, total_len);
- if (r < 0)
- goto done;
-
- p = full_buf;
- end = full_buf + r;
- dest = names;
- dest_end = names + len;
-
- while (p < end) {
- char name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
- int attr_len = strlen(p);
- bool is_first;
- int name_len = translate_raw_name(p, name, sizeof(name), &is_first);
- if (is_first) {
- if (dest + name_len > dest_end) {
- r = -ERANGE;
- goto done;
- }
- strcpy(dest, name);
- dest += name_len + 1;
- }
- p += attr_len + 1;
- }
- r = dest - names;
-
-done:
- free(full_buf);
- return r;
-}
Code Review / stor4nfv.git / blobdiff