--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
+ * vim:expandtab:shiftwidth=8:tabstop=8:
+ *
+ * linux/mds/mds_fs.c
+ *
+ * Lustre Metadata Server (MDS) filesystem interface code
+ *
+ * Copyright (C) 2002 Cluster File Systems, Inc.
+ *
+ * This code is issued under the GNU General Public License.
+ * See the file COPYING in this distribution
+ *
+ * by Andreas Dilger <adilger@clusterfs.com>
+ *
+ */
+
+#define EXPORT_SYMTAB
+#define DEBUG_SUBSYSTEM S_MDS
+
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/lustre_mds.h>
+
+LIST_HEAD(mds_fs_types);
+
+struct mds_fs_type {
+ struct list_head mft_list;
+ struct mds_fs_operations *mft_ops;
+ char *mft_name;
+};
+
+/* This will be a hash table at some point. */
+static int mds_init_client_data(struct mds_obd *mds)
+{
+ INIT_LIST_HEAD(&mds->mds_client_info);
+ return 0;
+}
+
+#define MDS_MAX_CLIENTS 1024
+#define MDS_MAX_CLIENT_WORDS (MDS_MAX_CLIENTS / sizeof(unsigned long))
+
+static unsigned long last_rcvd_slots[MDS_MAX_CLIENT_WORDS];
+
+/* Add client data to the MDS. The in-memory storage will be a hash at some
+ * point. We use a bitmap to locate a free space in the last_rcvd file if
+ * cl_off is -1 (i.e. a new client). Otherwise, we have just read the data
+ * from the last_rcvd file and we know its offset.
+ */
+int mds_client_add(struct mds_obd *mds, struct mds_client_data *mcd, int cl_off)
+{
+ struct mds_client_info *mci;
+
+ OBD_ALLOC(mci, sizeof(*mci));
+ if (!mci) {
+ CERROR("no memory for MDS client info\n");
+ RETURN(-ENOMEM);
+ }
+ INIT_LIST_HEAD(&mci->mci_open_head);
+
+ CDEBUG(D_INFO, "client at offset %d with UUID '%s' added\n",
+ cl_off, mcd->mcd_uuid);
+
+ if (cl_off == -1) {
+ unsigned long *word;
+ int bit;
+
+ repeat:
+ word = last_rcvd_slots;
+ while(*word == ~0UL)
+ ++word;
+ if (word - last_rcvd_slots >= MDS_MAX_CLIENT_WORDS) {
+ CERROR("no room in client MDS bitmap - fix code\n");
+ return -ENOMEM;
+ }
+ bit = ffz(*word);
+ if (test_and_set_bit(bit, word)) {
+ CERROR("found bit %d set for word %d - fix code\n",
+ bit, word - last_rcvd_slots);
+ goto repeat;
+ }
+ cl_off = word - last_rcvd_slots + bit;
+ } else {
+ if (test_and_set_bit(cl_off, last_rcvd_slots)) {
+ CERROR("bit %d already set in bitmap - bad bad\n",
+ cl_off);
+ LBUG();
+ }
+ }
+
+ mci->mci_mcd = mcd;
+ mci->mci_off = cl_off;
+
+ /* For now we just put the clients in a list, not a hashed list */
+ list_add_tail(&mci->mci_list, &mds->mds_client_info);
+
+ mds->mds_client_count++;
+
+ return 0;
+}
+
+void mds_client_del(struct mds_obd *mds, struct mds_client_info *mci)
+{
+ unsigned long *word;
+ int bit;
+
+ word = last_rcvd_slots + mci->mci_off / sizeof(unsigned long);
+ bit = mci->mci_off % sizeof(unsigned long);
+
+ if (!test_and_clear_bit(bit, word)) {
+ CERROR("bit %d already clear in word %d - bad bad\n",
+ bit, word - last_rcvd_slots);
+ LBUG();
+ }
+
+ --mds->mds_client_count;
+ list_del(&mci->mci_list);
+ OBD_FREE(mci->mci_mcd, sizeof(*mci->mci_mcd));
+ OBD_FREE(mci, sizeof (*mci));
+}
+
+static int mds_client_free_all(struct mds_obd *mds)
+{
+ struct list_head *p, *n;
+
+ list_for_each_safe(p, n, &mds->mds_client_info) {
+ struct mds_client_info *mci;
+
+ mci = list_entry(p, struct mds_client_info, mci_list);
+ mds_client_del(mds, mci);
+ }
+
+ return 0;
+}
+
+static int mds_server_free_data(struct mds_obd *mds)
+{
+ OBD_FREE(mds->mds_server_data, sizeof(*mds->mds_server_data));
+ mds->mds_server_data = NULL;
+
+ return 0;
+}
+
+#define LAST_RCVD "last_rcvd"
+
+static int mds_read_last_rcvd(struct mds_obd *mds, struct file *f)
+{
+ struct mds_server_data *msd;
+ struct mds_client_data *mcd = NULL;
+ loff_t fsize = f->f_dentry->d_inode->i_size;
+ loff_t off = 0;
+ int cl_off;
+ __u64 last_rcvd = 0;
+ __u64 last_mount;
+ int rc = 0;
+
+ OBD_ALLOC(msd, sizeof(*msd));
+ if (!msd)
+ RETURN(-ENOMEM);
+ rc = lustre_fread(f, (char *)msd, sizeof(*msd), &off);
+
+ mds->mds_server_data = msd;
+ if (rc == 0) {
+ CERROR("empty MDS %s, new MDS?\n", LAST_RCVD);
+ RETURN(0);
+ } else if (rc != sizeof(*msd)) {
+ CERROR("error reading MDS %s: rc = %d\n", LAST_RCVD, rc);
+ if (rc > 0) {
+ rc = -EIO;
+ }
+ GOTO(err_msd, rc);
+ }
+
+ /*
+ * When we do a clean MDS shutdown, we save the last_rcvd into
+ * the header. If we find clients with higher last_rcvd values
+ * then those clients may need recovery done.
+ */
+ last_rcvd = le64_to_cpu(msd->msd_last_rcvd);
+ mds->mds_last_rcvd = last_rcvd;
+ CDEBUG(D_INODE, "got %Lu for server last_rcvd value\n",
+ (unsigned long long)last_rcvd);
+
+ last_mount = le64_to_cpu(msd->msd_mount_count);
+ mds->mds_mount_count = last_mount;
+ CDEBUG(D_INODE, "got %Lu for server last_mount value\n",
+ (unsigned long long)last_mount);
+
+ for (off = MDS_LR_CLIENT, cl_off = 0, rc = sizeof(*mcd);
+ off <= fsize - sizeof(*mcd) && rc == sizeof(*mcd);
+ off = MDS_LR_CLIENT + ++cl_off * MDS_LR_SIZE) {
+ if (!mcd)
+ OBD_ALLOC(mcd, sizeof(*mcd));
+ if (!mcd)
+ GOTO(err_msd, rc = -ENOMEM);
+
+ rc = lustre_fread(f, (char *)mcd, sizeof(*mcd), &off);
+ if (rc != sizeof(*mcd)) {
+ CERROR("error reading MDS %s offset %d: rc = %d\n",
+ LAST_RCVD, cl_off, rc);
+ if (rc > 0)
+ rc = -EIO;
+ break;
+ }
+
+ last_rcvd = le64_to_cpu(mcd->mcd_last_rcvd);
+ last_mount = le64_to_cpu(mcd->mcd_mount_count);
+
+ if (last_rcvd &&
+ last_mount - mcd->mcd_mount_count < MDS_MOUNT_RECOV) {
+ rc = mds_client_add(mds, mcd, cl_off);
+ if (rc) {
+ rc = 0;
+ break;
+ }
+ mcd = NULL;
+ } else {
+ CDEBUG(D_INFO,
+ "client at offset %d with UUID '%s' ignored\n",
+ cl_off, mcd->mcd_uuid);
+ }
+
+ if (last_rcvd > mds->mds_last_rcvd) {
+ CDEBUG(D_OTHER,
+ "client at offset %d has last_rcvd = %Lu\n",
+ cl_off, (unsigned long long)last_rcvd);
+ mds->mds_last_rcvd = last_rcvd;
+ }
+ }
+ CDEBUG(D_INODE, "got %Lu for highest last_rcvd value, %d clients\n",
+ (unsigned long long)mds->mds_last_rcvd, mds->mds_client_count);
+
+ /* After recovery, there can be no local uncommitted transactions */
+ mds->mds_last_committed = mds->mds_last_rcvd;
+
+ return 0;
+
+err_msd:
+ mds_server_free_data(mds);
+ return rc;
+}
+
+static int mds_fs_prep(struct mds_obd *mds)
+{
+ struct obd_run_ctxt saved;
+ struct dentry *dentry;
+ struct file *f;
+ int rc;
+
+ push_ctxt(&saved, &mds->mds_ctxt);
+ dentry = simple_mkdir(current->fs->pwd, "ROOT", 0700);
+ if (IS_ERR(dentry)) {
+ rc = PTR_ERR(dentry);
+ CERROR("cannot create ROOT directory: rc = %d\n", rc);
+ GOTO(err_pop, rc);
+ }
+ /* XXX probably want to hold on to this later... */
+ dput(dentry);
+ f = filp_open("ROOT", O_RDONLY, 0);
+ if (IS_ERR(f)) {
+ rc = PTR_ERR(f);
+ CERROR("cannot open ROOT: rc = %d\n", rc);
+ LBUG();
+ GOTO(err_pop, rc);
+ }
+
+ mds->mds_rootfid.id = f->f_dentry->d_inode->i_ino;
+ mds->mds_rootfid.generation = f->f_dentry->d_inode->i_generation;
+ mds->mds_rootfid.f_type = S_IFDIR;
+
+ rc = filp_close(f, 0);
+ if (rc) {
+ CERROR("cannot close ROOT: rc = %d\n", rc);
+ LBUG();
+ }
+
+ dentry = simple_mkdir(current->fs->pwd, "FH", 0700);
+ if (IS_ERR(dentry)) {
+ rc = PTR_ERR(dentry);
+ CERROR("cannot create FH directory: rc = %d\n", rc);
+ GOTO(err_pop, rc);
+ }
+ /* XXX probably want to hold on to this later... */
+ dput(dentry);
+
+ rc = mds_init_client_data(mds);
+ if (rc)
+ GOTO(err_pop, rc);
+
+ f = filp_open(LAST_RCVD, O_RDWR | O_CREAT, 0644);
+ if (IS_ERR(f)) {
+ rc = PTR_ERR(f);
+ CERROR("cannot open/create %s file: rc = %d\n", LAST_RCVD, rc);
+ GOTO(err_pop, rc = PTR_ERR(f));
+ }
+ if (!S_ISREG(f->f_dentry->d_inode->i_mode)) {
+ CERROR("%s is not a regular file!: mode = %o\n", LAST_RCVD,
+ f->f_dentry->d_inode->i_mode);
+ GOTO(err_pop, rc = -ENOENT);
+ }
+
+ rc = mds_fs_journal_data(mds, f);
+ if (rc) {
+ CERROR("cannot journal data on %s: rc = %d\n", LAST_RCVD, rc);
+ GOTO(err_filp, rc);
+ }
+
+ rc = mds_read_last_rcvd(mds, f);
+ if (rc) {
+ CERROR("cannot read %s: rc = %d\n", LAST_RCVD, rc);
+ GOTO(err_client, rc);
+ }
+ mds->mds_rcvd_filp = f;
+ pop_ctxt(&saved);
+
+ RETURN(0);
+
+err_client:
+ mds_client_free_all(mds);
+err_filp:
+ if (filp_close(f, 0))
+ CERROR("can't close %s after error\n", LAST_RCVD);
+err_pop:
+ pop_ctxt(&saved);
+
+ return rc;
+}
+
+static struct mds_fs_operations *mds_search_fs_type(const char *name)
+{
+ struct list_head *p;
+ struct mds_fs_type *type;
+
+ /* lock mds_fs_types list */
+ list_for_each(p, &mds_fs_types) {
+ type = list_entry(p, struct mds_fs_type, mft_list);
+ if (!strcmp(type->mft_name, name)) {
+ /* unlock mds_fs_types list */
+ return type->mft_ops;
+ }
+ }
+ /* unlock mds_fs_types list */
+ return NULL;
+}
+
+int mds_register_fs_type(struct mds_fs_operations *ops, const char *name)
+{
+ struct mds_fs_operations *found;
+ struct mds_fs_type *type;
+
+ if ((found = mds_search_fs_type(name))) {
+ if (found != ops) {
+ CERROR("different operations for type %s\n", name);
+ RETURN(-EEXIST);
+ }
+ return 0;
+ }
+ OBD_ALLOC(type, sizeof(*type));
+ if (!type)
+ RETURN(-ENOMEM);
+
+ INIT_LIST_HEAD(&type->mft_list);
+ type->mft_ops = ops;
+ type->mft_name = strdup(name);
+ if (!type->mft_name) {
+ OBD_FREE(type, sizeof(*type));
+ RETURN(-ENOMEM);
+ }
+ MOD_INC_USE_COUNT;
+ list_add(&type->mft_list, &mds_fs_types);
+
+ return 0;
+}
+
+void mds_unregister_fs_type(const char *name)
+{
+ struct list_head *p;
+
+ /* lock mds_fs_types list */
+ list_for_each(p, &mds_fs_types) {
+ struct mds_fs_type *type;
+
+ type = list_entry(p, struct mds_fs_type, mft_list);
+ if (!strcmp(type->mft_name, name)) {
+ list_del(p);
+ kfree(type->mft_name);
+ OBD_FREE(type, sizeof(*type));
+ MOD_DEC_USE_COUNT;
+ break;
+ }
+ }
+ /* unlock mds_fs_types list */
+}
+
+int mds_fs_setup(struct mds_obd *mds, struct vfsmount *mnt)
+{
+ struct mds_fs_operations *fs_ops;
+ int rc;
+
+ if (!(fs_ops = mds_search_fs_type(mds->mds_fstype))) {
+ char name[32];
+
+ snprintf(name, sizeof(name) - 1, "mds_%s", mds->mds_fstype);
+ name[sizeof(name) - 1] = '\0';
+
+ if ((rc = request_module(name))) {
+ fs_ops = mds_search_fs_type(mds->mds_fstype);
+ CDEBUG(D_INFO, "Loaded module '%s'\n", name);
+ if (!fs_ops)
+ rc = -ENOENT;
+ }
+
+ if (rc) {
+ CERROR("Can't find MDS fs interface '%s'\n", name);
+ RETURN(rc);
+ }
+ }
+
+ mds->mds_fsops = fs_ops;
+ mds->mds_vfsmnt = mnt;
+ mds->mds_ctxt.pwdmnt = mnt;
+ mds->mds_ctxt.pwd = mnt->mnt_root;
+ mds->mds_ctxt.fs = KERNEL_DS;
+
+ /*
+ * Replace the client filesystem delete_inode method with our own,
+ * so that we can clear the object ID before the inode is deleted.
+ * The fs_delete_inode method will call cl_delete_inode for us.
+ * We need to do this for the MDS superblock only, hence we install
+ * a modified copy of the original superblock method table.
+ *
+ * We still assume that there is only a single MDS client filesystem
+ * type, as we don't have access to the mds struct in delete_inode
+ * and store the client delete_inode method in a global table. This
+ * will only become a problem if/when multiple MDSs are running on a
+ * single host with different underlying filesystems.
+ */
+ OBD_ALLOC(mds->mds_sop, sizeof(*mds->mds_sop));
+ if (!mds->mds_sop)
+ RETURN(-ENOMEM);
+
+ memcpy(mds->mds_sop, mds->mds_sb->s_op, sizeof(*mds->mds_sop));
+ mds->mds_fsops->cl_delete_inode = mds->mds_sop->delete_inode;
+ mds->mds_sop->delete_inode = mds->mds_fsops->fs_delete_inode;
+ mds->mds_sb->s_op = mds->mds_sop;
+
+ rc = mds_fs_prep(mds);
+
+ if (rc)
+ OBD_FREE(mds->mds_sop, sizeof(*mds->mds_sop));
+
+ return rc;
+}
+
+void mds_fs_cleanup(struct mds_obd *mds)
+{
+ mds_client_free_all(mds);
+ mds_server_free_data(mds);
+
+ OBD_FREE(mds->mds_sop, sizeof(*mds->mds_sop));
+}
+
+EXPORT_SYMBOL(mds_register_fs_type);
+EXPORT_SYMBOL(mds_unregister_fs_type);
git://git.whamcloud.com / fs / lustre-release.git / commitdiff