* [PATCH 1/2] btrfs-progs: new "allocation_hint" property.
2022-03-06 18:15 [PATCH 0/2][V12] btrfs-progs: allocation_hint disk property Goffredo Baroncelli
@ 2022-03-06 18:15 ` Goffredo Baroncelli
2022-03-06 18:15 ` [PATCH 2/2] Update man page for allocator_hint property Goffredo Baroncelli
1 sibling, 0 replies; 3+ messages in thread
From: Goffredo Baroncelli @ 2022-03-06 18:15 UTC (permalink / raw)
To: linux-btrfs
Cc: Zygo Blaxell, Josef Bacik, David Sterba, Sinnamohideen Shafeeq,
Paul Jones, Boris Burkov, Goffredo Baroncelli
From: Goffredo Baroncelli <kreijack@inwind.it>
Handle the property allocation_hint of a btrfs device. Below
an example of use:
$ # set a new value
$ sudo btrfs property set /dev/vde allocation_hint DATA_ONLY
$ # get the current value
$ sudo btrfs property get /dev/vde allocation_hint
devid=4, path=/dev/vde: allocation_hint=DATA_ONLY
The following values are availables:
- DATA_ONLY
- DATA_PREFERRED (default)
- METADATA_PREFERRED
- METADATA_ONLY
Root privileges are required.
Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
---
cmds/property.c | 162 ++++++++++++++++++++++++++++++++++++++++++
kernel-shared/ctree.h | 13 ++++
2 files changed, 175 insertions(+)
diff --git a/cmds/property.c b/cmds/property.c
index b3ccc0ff..b35c8ed3 100644
--- a/cmds/property.c
+++ b/cmds/property.c
@@ -22,6 +22,7 @@
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/xattr.h>
+#include <sys/sysmacros.h>
#include <uuid/uuid.h>
#include <btrfsutil.h>
#include "cmds/commands.h"
@@ -30,6 +31,7 @@
#include "common/open-utils.h"
#include "common/utils.h"
#include "common/help.h"
+#include "common/path-utils.h"
#define XATTR_BTRFS_PREFIX "btrfs."
#define XATTR_BTRFS_PREFIX_LEN (sizeof(XATTR_BTRFS_PREFIX) - 1)
@@ -232,6 +234,160 @@ out:
return ret;
}
+static int btrfs_find_devid_and_mnt(const char *devpath, int *devid,
+ char *path, int maxpath)
+{
+ int ret, i, fd;
+ DIR *dir;
+ struct stat stdevpath;
+ struct btrfs_ioctl_fs_info_args fi_args;
+ struct btrfs_ioctl_dev_info_args dev_info;
+
+ ret = get_btrfs_mount(devpath, path, maxpath);
+ if (ret)
+ return ret;
+
+ fd = btrfs_open_dir(path, &dir, 1);
+ if (fd < 0)
+ return fd;
+
+ ret = stat(devpath, &stdevpath);
+ if (ret) {
+ error("cannot stat '%s'", devpath);
+ goto out;
+ }
+
+ ret = ioctl(fd, BTRFS_IOC_FS_INFO, &fi_args);
+ if (ret < 0) {
+ if (errno == EPERM)
+ return -errno;
+ error("cannot get filesystem info: %m");
+ ret = -10;
+ goto out;
+ }
+
+ for (i = 0 ; i <= fi_args.max_id ; i++) {
+ struct stat st;
+
+ memset(&dev_info, 0, sizeof(dev_info));
+ ret = get_device_info(fd, i, &dev_info);
+ if (ret == -ENODEV)
+ continue;
+ if (ret) {
+ error("cannot get info about device devid=%d", i);
+ goto out;
+ }
+
+ if (!dev_info.path)
+ /* missing devices */
+ continue;
+
+ ret = stat((char *)dev_info.path, &st);
+ if (ret) {
+ error("cannot stat '%s'", devpath);
+ goto out;
+ }
+
+ if (major(st.st_rdev) == major(stdevpath.st_rdev) &&
+ minor(st.st_rdev) == minor(stdevpath.st_rdev)) {
+ *devid = dev_info.devid;
+ ret = 0;
+ goto out;
+ }
+ }
+
+ ret = -12;
+
+out:
+ close_file_or_dir(fd, dir);
+ return ret;
+}
+
+static int prop_allocation_hint(enum prop_object_type type,
+ const char *object,
+ const char *name,
+ const char *value,
+ bool force)
+{
+ int ret, devid, fd, fd2;
+ char path[PATH_MAX];
+ DIR *dir;
+ u8 fsid[BTRFS_UUID_SIZE];
+ char fsid_str[BTRFS_UUID_UNPARSED_SIZE];
+ char sysfs_file[PATH_MAX];
+ char filename[PATH_MAX];
+ char buf[1024];
+
+ ret = btrfs_find_devid_and_mnt(object, &devid, path, sizeof(path));
+ if (ret)
+ return -5;
+
+ fd = btrfs_open_dir(path, &dir, 1);
+ if (fd < 0)
+ return fd;
+
+ ret = get_fsid_fd(fd, fsid);
+ if (ret < 0)
+ goto out;
+
+ uuid_unparse(fsid, fsid_str);
+ sprintf(filename, "devinfo/%d/allocation_hint", devid);
+
+ /* build /sys/fs/btrfs/<UUID>/devinfo/<DEVID>/type */
+ ret = path_cat3_out(sysfs_file, "/sys/fs/btrfs", fsid_str, filename);
+ if (ret < 0)
+ goto out;
+
+ fd2 = open(sysfs_file, O_RDONLY);
+ if (fd2 < 0) {
+ error("'allocation_hint' property not available or accessible.");
+ ret = -errno;
+ goto out;
+ }
+
+ ret = read(fd2, buf, sizeof(buf) - 1);
+ close(fd2);
+ if (ret < 0) {
+ error("Unable to read the 'allocation_hint' property.");
+ ret = -errno;
+ goto out;
+ }
+
+ buf[sizeof(buf) - 1] = 0;
+
+ if (!value) {
+ /* READ */
+ printf("devid=%d, path=%s: allocation_hint=%s\n",
+ devid, object, buf);
+ ret = 0;
+ } else {
+ /* WRITE */
+ fd2 = open(sysfs_file, O_RDWR);
+ if (fd2 < 0) {
+ error("'allocation_hint' not accessible for updating.");
+ ret = -errno;
+ goto out;
+ }
+
+ ret = write(fd2, value, strlen(value));
+ close(fd2);
+ if (ret < 0) {
+ if (errno == EINVAL)
+ error("Invalid '%s' allocation_hint property.", value);
+ else
+ error("Unable to update 'allocation_hint' property.");
+ ret = -errno;
+ goto out;
+ }
+
+ }
+
+ ret = 0;
+out:
+ close_file_or_dir(fd, dir);
+ return ret;
+}
+
const struct prop_handler prop_handlers[] = {
{
.name ="ro",
@@ -254,6 +410,12 @@ const struct prop_handler prop_handlers[] = {
.types = prop_object_inode,
.handler = prop_compression
},
+ {
+ .name = "allocation_hint",
+ .desc = "hint to store the data/metadata chunks",
+ .types = prop_object_dev,
+ .handler = prop_allocation_hint
+ },
{NULL, NULL, 0, 0, NULL}
};
diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index de5452f2..7bff3952 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -216,6 +216,19 @@ struct btrfs_mapping_tree {
struct cache_tree cache_tree;
};
+/* btrfs chunk allocation hints */
+#define BTRFS_DEV_ALLOCATION_HINT_BIT_COUNT 2
+#define BTRFS_DEV_ALLOCATION_HINT_MASK ((1ULL << \
+ BTRFS_DEV_ALLOCATION_HINT_BIT_COUNT) - 1)
+/* preferred metadata chunk, but data chunk allowed */
+#define BTRFS_DEV_ALLOCATION_HINT_METADATA_PREFERRED (1ULL)
+/* only metadata chunk are allowed */
+#define BTRFS_DEV_ALLOCATION_HINT_METADATA_ONLY (2ULL)
+/* only data chunk allowed */
+#define BTRFS_DEV_ALLOCATION_HINT_DATA_ONLY (3ULL)
+/* preferred data chunk, but metadata chunk allowed */
+#define BTRFS_DEV_ALLOCATION_HINT_DATA_PREFERRED (0ULL)
+
#define BTRFS_UUID_SIZE 16
struct btrfs_dev_item {
/* the internal btrfs device id */
--
2.35.1
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