Viewing: liblustreapi_pool.c
// SPDX-License-Identifier: LGPL-2.1+
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Pool pinning helpers for liblustreapi.
*/
#include <sys/types.h>
#include <sys/xattr.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <lnetconfig/cyaml.h>
#include <linux/lustre/lustre_user.h>
#include "lustreapi_internal.h"
#define PIN_YAML_POOL_STR "pool"
static int pool_pin_ensure_entry(struct cYAML *yaml, const char *pool_name,
char *buff, size_t bufflen)
{
struct cYAML *node;
/* Search for an existing entry. */
for (node = yaml->cy_child; node != NULL; node = node->cy_next) {
if (strcmp(node->cy_string, PIN_YAML_POOL_STR) == 0 &&
node->cy_type == CYAML_TYPE_STRING &&
node->cy_valuestring != NULL &&
strcmp(node->cy_valuestring, pool_name) == 0)
break;
}
/* If not found, create a new entry. */
if (node == NULL) {
node = cYAML_create_string(yaml, (char *)PIN_YAML_POOL_STR,
(char *)pool_name);
if (node == NULL)
return -errno ? -errno : -ENOMEM;
}
/* Serialise the (possibly updated) YAML object into buff. */
errno = -dump_pin_object(yaml, buff, bufflen);
if (errno)
return -errno;
/* buff now contains the new serialised lustre.pin value. */
return 0;
}
static int pool_unpin_update_entry(struct cYAML *yaml, const char *pool_name,
char *buff, size_t bufflen)
{
struct cYAML *node;
/* We have a valid pin object, search for the entry to be deleted. */
for (node = yaml->cy_child; node != NULL; node = node->cy_next) {
if (strcmp(node->cy_string, PIN_YAML_POOL_STR) == 0 &&
node->cy_type == CYAML_TYPE_STRING &&
node->cy_valuestring != NULL &&
strcmp(node->cy_valuestring, pool_name) == 0)
break;
}
if (node == NULL) {
/* No matching pool entry in lustre.pin. */
errno = ENOENT;
return -ENOENT;
}
/* Remove the node from the YAML tree. */
if (node == yaml->cy_child) {
/* the first child */
if (node->cy_next)
node->cy_next->cy_prev = NULL;
yaml->cy_child = node->cy_next;
} else {
/* not the first child */
node->cy_prev->cy_next = node->cy_next;
if (node->cy_next)
node->cy_next->cy_prev = node->cy_prev;
}
node->cy_prev = node->cy_next = NULL;
cYAML_free_tree(node);
errno = -dump_pin_object(yaml, buff, bufflen);
if (errno)
return -errno;
return 0;
}
static int pool_is_pinned_from_yaml(struct cYAML *yaml, const char *pool_name)
{
struct cYAML *node;
int pinned = 0;
for (node = yaml->cy_child; node != NULL; node = node->cy_next) {
if (strcmp(node->cy_string, PIN_YAML_POOL_STR) == 0 &&
node->cy_type == CYAML_TYPE_STRING &&
node->cy_valuestring != NULL &&
strcmp(node->cy_valuestring, pool_name) == 0) {
pinned = 1;
break;
}
}
cYAML_free_tree(yaml);
return pinned;
}
/**
* llapi_pool_pin_fd() - Pin a file for a given pool name using an open fd.
* @fd: Open file descriptor for a Lustre file.
* @pool_name: Name of the pool to pin for (optionally fsname-qualified).
*
* Ensure that a "pool: pool_name" entry exists in the lustre.pin xattr of the
* file referenced by @fd. If such an entry already exists, this function
* succeeds without modifying the xattr.
*
* Return: 0 on success; on failure, a negative errno value is returned and
* errno is set to the corresponding error code.
*/
int llapi_pool_pin_fd(int fd, const char *pool_name)
{
int rc = 0;
struct cYAML *yaml = NULL;
char buff[XATTR_SIZE_MAX];
if (!llapi_pool_name_is_valid(&pool_name)) {
errno = EINVAL;
return -errno;
}
yaml = read_pin_xattr_object_fd(fd);
if (yaml == NULL && errno == ENODATA) {
snprintf(buff, sizeof(buff), "[%s: %s]", PIN_YAML_POOL_STR,
pool_name);
} else if (yaml == NULL) {
return -errno;
} else {
rc = pool_pin_ensure_entry(yaml, pool_name, buff, sizeof(buff));
if (rc < 0)
goto out;
}
if (fsetxattr(fd, XATTR_LUSTRE_PIN, buff, strlen(buff), 0) < 0)
rc = -errno;
else
rc = 0;
out:
if (yaml)
cYAML_free_tree(yaml);
return rc;
}
/**
* llapi_pool_pin_file() - Pin a file for a given pool name using a path.
* @path: Path to a Lustre file.
* @pool_name: Name of the pool to pin for (optionally fsname-qualified).
*
* Ensure that a "pool: pool_name" entry exists in the lustre.pin xattr of the
* file at @path. If such an entry already exists, this function succeeds
* without modifying the xattr.
*
* Return: 0 on success; on failure, a negative errno value is returned and
* errno is set to the corresponding error code.
*/
int llapi_pool_pin_file(const char *path, const char *pool_name)
{
int rc = 0;
struct cYAML *yaml = NULL;
char buff[XATTR_SIZE_MAX];
if (!llapi_pool_name_is_valid(&pool_name)) {
errno = EINVAL;
return -errno;
}
yaml = read_pin_xattr_object(path);
if (yaml == NULL && errno == ENODATA) {
snprintf(buff, sizeof(buff), "[%s: %s]", PIN_YAML_POOL_STR,
pool_name);
} else if (yaml == NULL) {
llapi_error(LLAPI_MSG_ERROR, errno,
"cannot read or parse pin xattr of file '%s'.",
path);
rc = -errno;
goto out;
} else {
rc = pool_pin_ensure_entry(yaml, pool_name, buff, sizeof(buff));
if (rc < 0)
goto out;
}
if (setxattr(path, XATTR_LUSTRE_PIN, buff, strlen(buff), 0) < 0)
rc = -errno;
else
rc = 0;
out:
if (yaml)
cYAML_free_tree(yaml);
return rc;
}
/**
* llapi_pool_pin_fid() - Pin a file for a given pool name using its FID.
* @lustre_dir: Path within the target Lustre filesystem (usually the mount).
* @fid: FID of the file to be pinned.
* @pool_name: Name of the pool to pin for (optionally fsname-qualified).
*
* Open the object referenced by @fid in @lustre_dir, then ensure a
* corresponding "pool: pool_name" entry exists in its lustre.pin xattr.
*
* Return: 0 on success; on failure, a negative errno value is returned and
* errno is set to the corresponding error code.
*/
int llapi_pool_pin_fid(const char *lustre_dir, const struct lu_fid *fid,
const char *pool_name)
{
int fd;
int rc;
fd = llapi_open_by_fid(lustre_dir, fid, O_RDONLY | O_NONBLOCK);
if (fd < 0)
return fd; /* negative errno, errno set by helper */
rc = llapi_pool_pin_fd(fd, pool_name);
if (rc < 0) {
int saved_errno = errno;
close(fd);
errno = saved_errno;
return rc;
}
close(fd);
return 0;
}
/**
* llapi_pool_unpin_fd() - Remove a pool pin from a file (by fd).
* @fd: Open file descriptor for a Lustre file.
* @pool_name: Name of the pool to unpin (optionally fsname-qualified).
*
* Remove the "pool: pool_name" entry from the lustre.pin xattr of the file
* referenced by @fd. If no matching entry exists (or the attribute is
* missing), this is treated as an error and ENOENT is reported. When the last
* entry is removed, the lustre.pin xattr itself is deleted.
*
* Return: 0 on success; on failure, a negative errno value is returned and
* errno is set to the corresponding error code.
*/
int llapi_pool_unpin_fd(int fd, const char *pool_name)
{
int rc = 0;
struct cYAML *yaml = NULL;
char buff[XATTR_SIZE_MAX];
if (!llapi_pool_name_is_valid(&pool_name)) {
errno = EINVAL;
return -errno;
}
yaml = read_pin_xattr_object_fd(fd);
if (yaml == NULL && errno == ENODATA) {
errno = ENOENT;
return -errno;
}
if (yaml == NULL)
return -errno;
rc = pool_unpin_update_entry(yaml, pool_name, buff, sizeof(buff));
if (rc < 0)
goto out;
if (strlen(buff) == 0) {
if (fremovexattr(fd, XATTR_LUSTRE_PIN) < 0)
rc = -errno;
else
rc = 0;
} else {
if (fsetxattr(fd, XATTR_LUSTRE_PIN, buff, strlen(buff), 0) < 0)
rc = -errno;
else
rc = 0;
}
out:
if (yaml)
cYAML_free_tree(yaml);
return rc;
}
/**
* llapi_pool_unpin_file() - Remove a pool pin from a file.
* @path: Path to a Lustre file.
* @pool_name: Name of the pool to unpin (optionally fsname-qualified).
*
* Remove the "pool: pool_name" entry from the lustre.pin xattr of @path. If
* no matching entry exists (or the attribute is missing), this is treated as
* an error and ENOENT is reported. When the last entry is removed, the
* lustre.pin xattr itself is deleted.
*
* Return: 0 on success; on failure, a negative errno value is returned and
* errno is set to the corresponding error code.
*/
int llapi_pool_unpin_file(const char *path, const char *pool_name)
{
int rc = 0;
struct cYAML *yaml = NULL;
char buff[XATTR_SIZE_MAX];
if (!llapi_pool_name_is_valid(&pool_name)) {
errno = EINVAL;
return -errno;
}
yaml = read_pin_xattr_object(path);
if (yaml == NULL && errno == ENODATA) {
errno = ENOENT;
rc = -errno;
goto out;
}
if (yaml == NULL) {
llapi_error(LLAPI_MSG_ERROR, errno,
"cannot read or parse pin xattr of file '%s'.",
path);
rc = -errno;
goto out;
}
rc = pool_unpin_update_entry(yaml, pool_name, buff, sizeof(buff));
if (rc < 0)
goto out;
if (strlen(buff) == 0) {
if (removexattr(path, XATTR_LUSTRE_PIN) < 0)
rc = -errno;
else
rc = 0;
} else {
if (setxattr(path, XATTR_LUSTRE_PIN, buff, strlen(buff), 0) < 0)
rc = -errno;
else
rc = 0;
}
out:
if (yaml)
cYAML_free_tree(yaml);
return rc;
}
/**
* llapi_pool_unpin_fid() - Remove a pool pin from a FID-referenced file.
* @lustre_dir: Path within the target Lustre filesystem (usually the mount).
* @fid: FID of the file to be unpinned.
* @pool_name: Name of the pool to unpin (optionally fsname-qualified).
*
* Open the object referenced by @fid in @lustre_dir and remove the
* corresponding "pool: pool_name" entry from its lustre.pin xattr.
*
* Return: 0 on success; on failure, a negative errno value is returned and
* errno is set to the corresponding error code.
*/
int llapi_pool_unpin_fid(const char *lustre_dir, const struct lu_fid *fid,
const char *pool_name)
{
int fd;
int rc;
fd = llapi_open_by_fid(lustre_dir, fid, O_RDONLY | O_NONBLOCK);
if (fd < 0)
return fd;
rc = llapi_pool_unpin_fd(fd, pool_name);
if (rc < 0) {
int saved_errno = errno;
close(fd);
errno = saved_errno;
return rc;
}
close(fd);
return 0;
}
/**
* llapi_pool_is_pinned_fd() - Test if a file is pinned for a pool name (fd).
* @fd: Open file descriptor for a Lustre file.
* @pool_name: Pool name to test (optionally fsname-qualified).
*
* Check whether the lustre.pin xattr of the file referenced by @fd contains
* a "pool: pool_name" entry.
*
* Return: 1 if such an entry exists, 0 if not. On error, a negative errno
* value is returned.
*/
int llapi_pool_is_pinned_fd(int fd, const char *pool_name)
{
struct cYAML *yaml;
if (!llapi_pool_name_is_valid(&pool_name)) {
errno = EINVAL;
return -errno;
}
yaml = read_pin_xattr_object_fd(fd);
if (yaml == NULL) {
/*
* No lustre.pin attribute: treat as "not pinned".
* Any other error is propagated as -errno.
*/
if (errno == ENODATA)
return 0;
return -errno;
}
return pool_is_pinned_from_yaml(yaml, pool_name);
}
/**
* llapi_pool_is_pinned_file() - Test if a file is pinned for a pool name.
* @path: Path to a Lustre file.
* @pool_name: Pool name to test (optionally fsname-qualified).
*
* Check whether the lustre.pin xattr of the file at @path contains a
* "pool: pool_name" entry.
*
* Return: 1 if such an entry exists, 0 if not. On error, a negative errno
* value is returned.
*/
int llapi_pool_is_pinned_file(const char *path, const char *pool_name)
{
struct cYAML *yaml;
if (!llapi_pool_name_is_valid(&pool_name)) {
errno = EINVAL;
return -errno;
}
yaml = read_pin_xattr_object(path);
if (yaml == NULL) {
if (errno == ENODATA)
return 0;
return -errno;
}
return pool_is_pinned_from_yaml(yaml, pool_name);
}
/**
* llapi_pool_is_pinned_fid() - Test if a FID-referenced file is pool-pinned.
* @lustre_dir: Path within the target Lustre filesystem (usually the mount).
* @fid: FID of the file to be checked.
* @pool_name: Pool name to test (optionally fsname-qualified).
*
* Open the object referenced by @fid in @lustre_dir and check whether its
* lustre.pin xattr contains a "pool: pool_name" entry.
*
* Return: 1 if such an entry exists, 0 if not. On error, a negative errno
* value is returned, including failures from llapi_open_by_fid().
*/
int llapi_pool_is_pinned_fid(const char *lustre_dir, const struct lu_fid *fid,
const char *pool_name)
{
int fd;
int pinned;
fd = llapi_open_by_fid(lustre_dir, fid, O_RDONLY | O_NONBLOCK);
if (fd < 0)
return fd;
pinned = llapi_pool_is_pinned_fd(fd, pool_name);
if (pinned < 0) {
int saved_errno = errno;
close(fd);
errno = saved_errno;
return pinned;
}
close(fd);
return pinned;
}
