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authorStefan Metzmacher <metze@samba.org>2007-08-10 09:05:18 +0000
committerGerald (Jerry) Carter <jerry@samba.org>2007-10-10 12:29:25 -0500
commitd68145a509b3e86e0d5ff44260f968eb1f39dfeb (patch)
treec2b1209ccea3ef2b36a7be2d84f56645fb375e78 /source3/modules
parentb87c0dde7123b7598b49a236a76641846b885bf5 (diff)
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r24302: add a module that overloads the file_id_create VFS function
and alters the device id depending on the configured algorithm. The algorithm is configured via "fileid:algorithm": - "fsname" (default) uses a uint64 hash over the mount point - "fsid" uses the fsid returned from statfs() This is needed for "clustering = yes" on some clusterfilesystems metze (This used to be commit 30f9171cca3e4f523cde7dfc96096c32e5af50be)
Diffstat (limited to 'source3/modules')
-rw-r--r--source3/modules/vfs_fileid.c288
1 files changed, 288 insertions, 0 deletions
diff --git a/source3/modules/vfs_fileid.c b/source3/modules/vfs_fileid.c
new file mode 100644
index 0000000000..5954a10ddb
--- /dev/null
+++ b/source3/modules/vfs_fileid.c
@@ -0,0 +1,288 @@
+/*
+ * VFS module to alter the algorithm to calculate
+ * the struct file_id used as key for the share mode
+ * and byte range locking db's.
+ *
+ * Copyright (C) 2007, Stefan Metzmacher
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "includes.h"
+
+static int vfs_fileid_debug_level = DBGC_VFS;
+
+#undef DBGC_CLASS
+#define DBGC_CLASS vfs_fileid_debug_level
+
+struct fileid_mount_entry {
+ SMB_DEV_T device;
+ const char *mnt_fsname;
+ fsid_t fsid;
+ uint64_t devid;
+};
+
+struct fileid_handle_data {
+ uint64_t (*device_mapping_fn)(struct fileid_handle_data *data,
+ SMB_DEV_T dev);
+ unsigned num_mount_entries;
+ struct fileid_mount_entry *mount_entries;
+};
+
+/* load all the mount entries from the mtab */
+static void fileid_load_mount_entries(struct fileid_handle_data *data)
+{
+ FILE *f;
+ struct mntent *m;
+
+ data->num_mount_entries = 0;
+ TALLOC_FREE(data->mount_entries);
+
+ f = setmntent("/etc/mtab", "r");
+ if (!f) return;
+
+ while ((m = getmntent(f))) {
+ struct stat st;
+ struct statfs sfs;
+ struct fileid_mount_entry *cur;
+
+ if (stat(m->mnt_dir, &st) != 0) continue;
+ if (statfs(m->mnt_dir, &sfs) != 0) continue;
+
+ if (strncmp(m->mnt_fsname, "/dev/", 5) == 0) {
+ m->mnt_fsname += 5;
+ }
+
+ data->mount_entries = TALLOC_REALLOC_ARRAY(data,
+ data->mount_entries,
+ struct fileid_mount_entry,
+ data->num_mount_entries+1);
+ if (data->mount_entries == NULL) {
+ goto nomem;
+ }
+
+ cur = &data->mount_entries[data->num_mount_entries];
+ cur->device = st.st_dev;
+ cur->mnt_fsname = talloc_strdup(data->mount_entries,
+ m->mnt_fsname);
+ if (!cur->mnt_fsname) goto nomem;
+ cur->fsid = sfs.f_fsid;
+ cur->devid = (uint64_t)-1;
+
+ data->num_mount_entries++;
+ }
+ endmntent(f);
+ return;
+
+nomem:
+ if (f) endmntent(f);
+
+ data->num_mount_entries = 0;
+ TALLOC_FREE(data->mount_entries);
+
+ return;
+}
+
+/* find a mount entry given a dev_t */
+static struct fileid_mount_entry *fileid_find_mount_entry(struct fileid_handle_data *data,
+ SMB_DEV_T dev)
+{
+ int i;
+
+ if (data->num_mount_entries == 0) {
+ fileid_load_mount_entries(data);
+ }
+ for (i=0;i<data->num_mount_entries;i++) {
+ if (data->mount_entries[i].device == dev) {
+ return &data->mount_entries[i];
+ }
+ }
+ /* 2nd pass after reloading */
+ fileid_load_mount_entries(data);
+ for (i=0;i<data->num_mount_entries;i++) {
+ if (data->mount_entries[i].device == dev) {
+ return &data->mount_entries[i];
+ }
+ }
+ return NULL;
+}
+
+
+/* a 64 bit hash, based on the one in tdb */
+static uint64_t fileid_uint64_hash(const uint8_t *s, size_t len)
+{
+ uint64_t value; /* Used to compute the hash value. */
+ uint32_t i; /* Used to cycle through random values. */
+
+ /* Set the initial value from the key size. */
+ for (value = 0x238F13AFLL * len, i=0; i < len; i++)
+ value = (value + (s[i] << (i*5 % 24)));
+
+ return (1103515243LL * value + 12345LL);
+}
+
+/* a device mapping using a fsname */
+static uint64_t fileid_device_mapping_fsname(struct fileid_handle_data *data,
+ SMB_DEV_T dev)
+{
+ struct fileid_mount_entry *m;
+
+ m = fileid_find_mount_entry(data, dev);
+ if (!m) return dev;
+
+ if (m->devid == (uint64_t)-1) {
+ m->devid = fileid_uint64_hash((uint8_t *)m->mnt_fsname,
+ strlen(m->mnt_fsname));
+ }
+
+ return m->devid;
+}
+
+/* device mapping functions using a fsid */
+static uint64_t fileid_device_mapping_fsid(struct fileid_handle_data *data,
+ SMB_DEV_T dev)
+{
+ struct fileid_mount_entry *m;
+
+ m = fileid_find_mount_entry(data, dev);
+ if (!m) return dev;
+
+ if (m->devid == (uint64_t)-1) {
+ if (sizeof(fsid_t) > sizeof(uint64_t)) {
+ m->devid = fileid_uint64_hash((uint8_t *)&m->fsid,
+ sizeof(m->fsid));
+ } else {
+ union {
+ uint64_t ret;
+ fsid_t fsid;
+ } u;
+ ZERO_STRUCT(u);
+ u.fsid = m->fsid;
+ m->devid = u.ret;
+ }
+ }
+
+ return m->devid;
+}
+
+static int fileid_connect(struct vfs_handle_struct *handle,
+ const char *service, const char *user)
+{
+ struct fileid_handle_data *data;
+ const char *algorithm;
+
+ data = talloc_zero(handle->conn->mem_ctx, struct fileid_handle_data);
+ if (!data) {
+ DEBUG(0, ("talloc_zero() failed\n"));
+ return -1;
+ }
+
+ data->device_mapping_fn = fileid_device_mapping_fsid;
+ algorithm = lp_parm_const_string(SNUM(handle->conn),
+ "fileid", "algorithm",
+ "fsname");
+ if (strcmp("fsname", algorithm) == 0) {
+ data->device_mapping_fn = fileid_device_mapping_fsname;
+ } else if (strcmp("fsid", algorithm) == 0) {
+ data->device_mapping_fn = fileid_device_mapping_fsid;
+ } else {
+ DEBUG(0,("fileid_connect(): unknown algorithm[%s]\n", algorithm));
+ return -1;
+ }
+
+ SMB_VFS_HANDLE_SET_DATA(handle, data, NULL,
+ struct fileid_handle_data,
+ return -1);
+
+ DEBUG(10, ("fileid_connect(): connect to service[%s] with algorithm[%s]\n",
+ service, algorithm));
+
+ return SMB_VFS_NEXT_CONNECT(handle, service, user);
+}
+
+static void fileid_disconnect(struct vfs_handle_struct *handle)
+{
+ DEBUG(10,("fileid_disconnect() connect to service[%s].\n",
+ lp_servicename(SNUM(handle->conn))));
+
+ SMB_VFS_NEXT_DISCONNECT(handle);
+}
+
+static struct file_id fileid_file_id_create(struct vfs_handle_struct *handle,
+ SMB_DEV_T dev, SMB_INO_T inode)
+{
+ struct fileid_handle_data *data;
+ struct file_id id;
+
+ ZERO_STRUCT(id);
+
+ SMB_VFS_HANDLE_GET_DATA(handle, data,
+ struct fileid_handle_data,
+ return id);
+
+ id.devid = data->device_mapping_fn(data, dev);
+ id.inode = inode;
+
+ return id;
+}
+
+static vfs_op_tuple fileid_ops[] = {
+
+ /* Disk operations */
+ {
+ SMB_VFS_OP(fileid_connect),
+ SMB_VFS_OP_CONNECT,
+ SMB_VFS_LAYER_TRANSPARENT
+ },
+ {
+ SMB_VFS_OP(fileid_disconnect),
+ SMB_VFS_OP_DISCONNECT,
+ SMB_VFS_LAYER_TRANSPARENT
+ },
+
+ /* File operations */
+ {
+ SMB_VFS_OP(fileid_file_id_create),
+ SMB_VFS_OP_FILE_ID_CREATE,
+ SMB_VFS_LAYER_OPAQUE
+ },
+
+ /* End marker */
+ {
+ SMB_VFS_OP(NULL),
+ SMB_VFS_OP_NOOP,
+ SMB_VFS_LAYER_NOOP
+ }
+};
+
+NTSTATUS vfs_fileid_init(void);
+NTSTATUS vfs_fileid_init(void)
+{
+ NTSTATUS ret;
+
+ ret = smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "fileid", fileid_ops);
+ if (!NT_STATUS_IS_OK(ret)) {
+ return ret;
+ }
+
+ vfs_fileid_debug_level = debug_add_class("fileid");
+ if (vfs_fileid_debug_level == -1) {
+ vfs_fileid_debug_level = DBGC_VFS;
+ DEBUG(0, ("vfs_fileid: Couldn't register custom debugging class!\n"));
+ } else {
+ DEBUG(10, ("vfs_fileid: Debug class number of 'fileid': %d\n", vfs_fileid_debug_level));
+ }
+
+ return ret;
+}