Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / exofs / super.c
diff --git a/kernel/fs/exofs/super.c b/kernel/fs/exofs/super.c
new file mode 100644 (file)
index 0000000..b795c56
--- /dev/null
@@ -0,0 +1,1049 @@
+/*
+ * Copyright (C) 2005, 2006
+ * Avishay Traeger (avishay@gmail.com)
+ * Copyright (C) 2008, 2009
+ * Boaz Harrosh <ooo@electrozaur.com>
+ *
+ * Copyrights for code taken from ext2:
+ *     Copyright (C) 1992, 1993, 1994, 1995
+ *     Remy Card (card@masi.ibp.fr)
+ *     Laboratoire MASI - Institut Blaise Pascal
+ *     Universite Pierre et Marie Curie (Paris VI)
+ *     from
+ *     linux/fs/minix/inode.c
+ *     Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * This file is part of exofs.
+ *
+ * exofs 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.  Since it is based on ext2, and the only
+ * valid version of GPL for the Linux kernel is version 2, the only valid
+ * version of GPL for exofs is version 2.
+ *
+ * exofs 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 exofs; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/string.h>
+#include <linux/parser.h>
+#include <linux/vfs.h>
+#include <linux/random.h>
+#include <linux/module.h>
+#include <linux/exportfs.h>
+#include <linux/slab.h>
+
+#include "exofs.h"
+
+#define EXOFS_DBGMSG2(M...) do {} while (0)
+
+/******************************************************************************
+ * MOUNT OPTIONS
+ *****************************************************************************/
+
+/*
+ * struct to hold what we get from mount options
+ */
+struct exofs_mountopt {
+       bool is_osdname;
+       const char *dev_name;
+       uint64_t pid;
+       int timeout;
+};
+
+/*
+ * exofs-specific mount-time options.
+ */
+enum { Opt_name, Opt_pid, Opt_to, Opt_err };
+
+/*
+ * Our mount-time options.  These should ideally be 64-bit unsigned, but the
+ * kernel's parsing functions do not currently support that.  32-bit should be
+ * sufficient for most applications now.
+ */
+static match_table_t tokens = {
+       {Opt_name, "osdname=%s"},
+       {Opt_pid, "pid=%u"},
+       {Opt_to, "to=%u"},
+       {Opt_err, NULL}
+};
+
+/*
+ * The main option parsing method.  Also makes sure that all of the mandatory
+ * mount options were set.
+ */
+static int parse_options(char *options, struct exofs_mountopt *opts)
+{
+       char *p;
+       substring_t args[MAX_OPT_ARGS];
+       int option;
+       bool s_pid = false;
+
+       EXOFS_DBGMSG("parse_options %s\n", options);
+       /* defaults */
+       memset(opts, 0, sizeof(*opts));
+       opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
+
+       while ((p = strsep(&options, ",")) != NULL) {
+               int token;
+               char str[32];
+
+               if (!*p)
+                       continue;
+
+               token = match_token(p, tokens, args);
+               switch (token) {
+               case Opt_name:
+                       opts->dev_name = match_strdup(&args[0]);
+                       if (unlikely(!opts->dev_name)) {
+                               EXOFS_ERR("Error allocating dev_name");
+                               return -ENOMEM;
+                       }
+                       opts->is_osdname = true;
+                       break;
+               case Opt_pid:
+                       if (0 == match_strlcpy(str, &args[0], sizeof(str)))
+                               return -EINVAL;
+                       opts->pid = simple_strtoull(str, NULL, 0);
+                       if (opts->pid < EXOFS_MIN_PID) {
+                               EXOFS_ERR("Partition ID must be >= %u",
+                                         EXOFS_MIN_PID);
+                               return -EINVAL;
+                       }
+                       s_pid = 1;
+                       break;
+               case Opt_to:
+                       if (match_int(&args[0], &option))
+                               return -EINVAL;
+                       if (option <= 0) {
+                               EXOFS_ERR("Timout must be > 0");
+                               return -EINVAL;
+                       }
+                       opts->timeout = option * HZ;
+                       break;
+               }
+       }
+
+       if (!s_pid) {
+               EXOFS_ERR("Need to specify the following options:\n");
+               EXOFS_ERR("    -o pid=pid_no_to_use\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+/******************************************************************************
+ * INODE CACHE
+ *****************************************************************************/
+
+/*
+ * Our inode cache.  Isn't it pretty?
+ */
+static struct kmem_cache *exofs_inode_cachep;
+
+/*
+ * Allocate an inode in the cache
+ */
+static struct inode *exofs_alloc_inode(struct super_block *sb)
+{
+       struct exofs_i_info *oi;
+
+       oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
+       if (!oi)
+               return NULL;
+
+       oi->vfs_inode.i_version = 1;
+       return &oi->vfs_inode;
+}
+
+static void exofs_i_callback(struct rcu_head *head)
+{
+       struct inode *inode = container_of(head, struct inode, i_rcu);
+       kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
+}
+
+/*
+ * Remove an inode from the cache
+ */
+static void exofs_destroy_inode(struct inode *inode)
+{
+       call_rcu(&inode->i_rcu, exofs_i_callback);
+}
+
+/*
+ * Initialize the inode
+ */
+static void exofs_init_once(void *foo)
+{
+       struct exofs_i_info *oi = foo;
+
+       inode_init_once(&oi->vfs_inode);
+}
+
+/*
+ * Create and initialize the inode cache
+ */
+static int init_inodecache(void)
+{
+       exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
+                               sizeof(struct exofs_i_info), 0,
+                               SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+                               exofs_init_once);
+       if (exofs_inode_cachep == NULL)
+               return -ENOMEM;
+       return 0;
+}
+
+/*
+ * Destroy the inode cache
+ */
+static void destroy_inodecache(void)
+{
+       /*
+        * Make sure all delayed rcu free inodes are flushed before we
+        * destroy cache.
+        */
+       rcu_barrier();
+       kmem_cache_destroy(exofs_inode_cachep);
+}
+
+/******************************************************************************
+ * Some osd helpers
+ *****************************************************************************/
+void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
+{
+       osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
+}
+
+static int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
+                   u64 offset, void *p, unsigned length)
+{
+       struct osd_request *or = osd_start_request(od, GFP_KERNEL);
+/*     struct osd_sense_info osi = {.key = 0};*/
+       int ret;
+
+       if (unlikely(!or)) {
+               EXOFS_DBGMSG("%s: osd_start_request failed.\n", __func__);
+               return -ENOMEM;
+       }
+       ret = osd_req_read_kern(or, obj, offset, p, length);
+       if (unlikely(ret)) {
+               EXOFS_DBGMSG("%s: osd_req_read_kern failed.\n", __func__);
+               goto out;
+       }
+
+       ret = osd_finalize_request(or, 0, cred, NULL);
+       if (unlikely(ret)) {
+               EXOFS_DBGMSG("Failed to osd_finalize_request() => %d\n", ret);
+               goto out;
+       }
+
+       ret = osd_execute_request(or);
+       if (unlikely(ret))
+               EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
+       /* osd_req_decode_sense(or, ret); */
+
+out:
+       osd_end_request(or);
+       EXOFS_DBGMSG2("read_kern(0x%llx) offset=0x%llx "
+                     "length=0x%llx dev=%p ret=>%d\n",
+                     _LLU(obj->id), _LLU(offset), _LLU(length), od, ret);
+       return ret;
+}
+
+static const struct osd_attr g_attr_sb_stats = ATTR_DEF(
+       EXOFS_APAGE_SB_DATA,
+       EXOFS_ATTR_SB_STATS,
+       sizeof(struct exofs_sb_stats));
+
+static int __sbi_read_stats(struct exofs_sb_info *sbi)
+{
+       struct osd_attr attrs[] = {
+               [0] = g_attr_sb_stats,
+       };
+       struct ore_io_state *ios;
+       int ret;
+
+       ret = ore_get_io_state(&sbi->layout, &sbi->oc, &ios);
+       if (unlikely(ret)) {
+               EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
+               return ret;
+       }
+
+       ios->in_attr = attrs;
+       ios->in_attr_len = ARRAY_SIZE(attrs);
+
+       ret = ore_read(ios);
+       if (unlikely(ret)) {
+               EXOFS_ERR("Error reading super_block stats => %d\n", ret);
+               goto out;
+       }
+
+       ret = extract_attr_from_ios(ios, &attrs[0]);
+       if (ret) {
+               EXOFS_ERR("%s: extract_attr of sb_stats failed\n", __func__);
+               goto out;
+       }
+       if (attrs[0].len) {
+               struct exofs_sb_stats *ess;
+
+               if (unlikely(attrs[0].len != sizeof(*ess))) {
+                       EXOFS_ERR("%s: Wrong version of exofs_sb_stats "
+                                 "size(%d) != expected(%zd)\n",
+                                 __func__, attrs[0].len, sizeof(*ess));
+                       goto out;
+               }
+
+               ess = attrs[0].val_ptr;
+               sbi->s_nextid = le64_to_cpu(ess->s_nextid);
+               sbi->s_numfiles = le32_to_cpu(ess->s_numfiles);
+       }
+
+out:
+       ore_put_io_state(ios);
+       return ret;
+}
+
+static void stats_done(struct ore_io_state *ios, void *p)
+{
+       ore_put_io_state(ios);
+       /* Good thanks nothing to do anymore */
+}
+
+/* Asynchronously write the stats attribute */
+int exofs_sbi_write_stats(struct exofs_sb_info *sbi)
+{
+       struct osd_attr attrs[] = {
+               [0] = g_attr_sb_stats,
+       };
+       struct ore_io_state *ios;
+       int ret;
+
+       ret = ore_get_io_state(&sbi->layout, &sbi->oc, &ios);
+       if (unlikely(ret)) {
+               EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
+               return ret;
+       }
+
+       sbi->s_ess.s_nextid   = cpu_to_le64(sbi->s_nextid);
+       sbi->s_ess.s_numfiles = cpu_to_le64(sbi->s_numfiles);
+       attrs[0].val_ptr = &sbi->s_ess;
+
+
+       ios->done = stats_done;
+       ios->private = sbi;
+       ios->out_attr = attrs;
+       ios->out_attr_len = ARRAY_SIZE(attrs);
+
+       ret = ore_write(ios);
+       if (unlikely(ret)) {
+               EXOFS_ERR("%s: ore_write failed.\n", __func__);
+               ore_put_io_state(ios);
+       }
+
+       return ret;
+}
+
+/******************************************************************************
+ * SUPERBLOCK FUNCTIONS
+ *****************************************************************************/
+static const struct super_operations exofs_sops;
+static const struct export_operations exofs_export_ops;
+
+/*
+ * Write the superblock to the OSD
+ */
+static int exofs_sync_fs(struct super_block *sb, int wait)
+{
+       struct exofs_sb_info *sbi;
+       struct exofs_fscb *fscb;
+       struct ore_comp one_comp;
+       struct ore_components oc;
+       struct ore_io_state *ios;
+       int ret = -ENOMEM;
+
+       fscb = kmalloc(sizeof(*fscb), GFP_KERNEL);
+       if (unlikely(!fscb))
+               return -ENOMEM;
+
+       sbi = sb->s_fs_info;
+
+       /* NOTE: We no longer dirty the super_block anywhere in exofs. The
+        * reason we write the fscb here on unmount is so we can stay backwards
+        * compatible with fscb->s_version == 1. (What we are not compatible
+        * with is if a new version FS crashed and then we try to mount an old
+        * version). Otherwise the exofs_fscb is read-only from mkfs time. All
+        * the writeable info is set in exofs_sbi_write_stats() above.
+        */
+
+       exofs_init_comps(&oc, &one_comp, sbi, EXOFS_SUPER_ID);
+
+       ret = ore_get_io_state(&sbi->layout, &oc, &ios);
+       if (unlikely(ret))
+               goto out;
+
+       ios->length = offsetof(struct exofs_fscb, s_dev_table_oid);
+       memset(fscb, 0, ios->length);
+       fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
+       fscb->s_numfiles = cpu_to_le64(sbi->s_numfiles);
+       fscb->s_magic = cpu_to_le16(sb->s_magic);
+       fscb->s_newfs = 0;
+       fscb->s_version = EXOFS_FSCB_VER;
+
+       ios->offset = 0;
+       ios->kern_buff = fscb;
+
+       ret = ore_write(ios);
+       if (unlikely(ret))
+               EXOFS_ERR("%s: ore_write failed.\n", __func__);
+
+out:
+       EXOFS_DBGMSG("s_nextid=0x%llx ret=%d\n", _LLU(sbi->s_nextid), ret);
+       ore_put_io_state(ios);
+       kfree(fscb);
+       return ret;
+}
+
+static void _exofs_print_device(const char *msg, const char *dev_path,
+                               struct osd_dev *od, u64 pid)
+{
+       const struct osd_dev_info *odi = osduld_device_info(od);
+
+       printk(KERN_NOTICE "exofs: %s %s osd_name-%s pid-0x%llx\n",
+               msg, dev_path ?: "", odi->osdname, _LLU(pid));
+}
+
+static void exofs_free_sbi(struct exofs_sb_info *sbi)
+{
+       unsigned numdevs = sbi->oc.numdevs;
+
+       while (numdevs) {
+               unsigned i = --numdevs;
+               struct osd_dev *od = ore_comp_dev(&sbi->oc, i);
+
+               if (od) {
+                       ore_comp_set_dev(&sbi->oc, i, NULL);
+                       osduld_put_device(od);
+               }
+       }
+       kfree(sbi->oc.ods);
+       kfree(sbi);
+}
+
+/*
+ * This function is called when the vfs is freeing the superblock.  We just
+ * need to free our own part.
+ */
+static void exofs_put_super(struct super_block *sb)
+{
+       int num_pend;
+       struct exofs_sb_info *sbi = sb->s_fs_info;
+
+       /* make sure there are no pending commands */
+       for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
+            num_pend = atomic_read(&sbi->s_curr_pending)) {
+               wait_queue_head_t wq;
+
+               printk(KERN_NOTICE "%s: !!Pending operations in flight. "
+                      "This is a BUG. please report to osd-dev@open-osd.org\n",
+                      __func__);
+               init_waitqueue_head(&wq);
+               wait_event_timeout(wq,
+                                 (atomic_read(&sbi->s_curr_pending) == 0),
+                                 msecs_to_jiffies(100));
+       }
+
+       _exofs_print_device("Unmounting", NULL, ore_comp_dev(&sbi->oc, 0),
+                           sbi->one_comp.obj.partition);
+
+       exofs_sysfs_sb_del(sbi);
+       bdi_destroy(&sbi->bdi);
+       exofs_free_sbi(sbi);
+       sb->s_fs_info = NULL;
+}
+
+static int _read_and_match_data_map(struct exofs_sb_info *sbi, unsigned numdevs,
+                                   struct exofs_device_table *dt)
+{
+       int ret;
+
+       sbi->layout.stripe_unit =
+                               le64_to_cpu(dt->dt_data_map.cb_stripe_unit);
+       sbi->layout.group_width =
+                               le32_to_cpu(dt->dt_data_map.cb_group_width);
+       sbi->layout.group_depth =
+                               le32_to_cpu(dt->dt_data_map.cb_group_depth);
+       sbi->layout.mirrors_p1  =
+                               le32_to_cpu(dt->dt_data_map.cb_mirror_cnt) + 1;
+       sbi->layout.raid_algorithm  =
+                               le32_to_cpu(dt->dt_data_map.cb_raid_algorithm);
+
+       ret = ore_verify_layout(numdevs, &sbi->layout);
+
+       EXOFS_DBGMSG("exofs: layout: "
+               "num_comps=%u stripe_unit=0x%x group_width=%u "
+               "group_depth=0x%llx mirrors_p1=%u raid_algorithm=%u\n",
+               numdevs,
+               sbi->layout.stripe_unit,
+               sbi->layout.group_width,
+               _LLU(sbi->layout.group_depth),
+               sbi->layout.mirrors_p1,
+               sbi->layout.raid_algorithm);
+       return ret;
+}
+
+static unsigned __ra_pages(struct ore_layout *layout)
+{
+       const unsigned _MIN_RA = 32; /* min 128K read-ahead */
+       unsigned ra_pages = layout->group_width * layout->stripe_unit /
+                               PAGE_SIZE;
+       unsigned max_io_pages = exofs_max_io_pages(layout, ~0);
+
+       ra_pages *= 2; /* two stripes */
+       if (ra_pages < _MIN_RA)
+               ra_pages = roundup(_MIN_RA, ra_pages / 2);
+
+       if (ra_pages > max_io_pages)
+               ra_pages = max_io_pages;
+
+       return ra_pages;
+}
+
+/* @odi is valid only as long as @fscb_dev is valid */
+static int exofs_devs_2_odi(struct exofs_dt_device_info *dt_dev,
+                            struct osd_dev_info *odi)
+{
+       odi->systemid_len = le32_to_cpu(dt_dev->systemid_len);
+       if (likely(odi->systemid_len))
+               memcpy(odi->systemid, dt_dev->systemid, OSD_SYSTEMID_LEN);
+
+       odi->osdname_len = le32_to_cpu(dt_dev->osdname_len);
+       odi->osdname = dt_dev->osdname;
+
+       /* FIXME support long names. Will need a _put function */
+       if (dt_dev->long_name_offset)
+               return -EINVAL;
+
+       /* Make sure osdname is printable!
+        * mkexofs should give us space for a null-terminator else the
+        * device-table is invalid.
+        */
+       if (unlikely(odi->osdname_len >= sizeof(dt_dev->osdname)))
+               odi->osdname_len = sizeof(dt_dev->osdname) - 1;
+       dt_dev->osdname[odi->osdname_len] = 0;
+
+       /* If it's all zeros something is bad we read past end-of-obj */
+       return !(odi->systemid_len || odi->osdname_len);
+}
+
+static int __alloc_dev_table(struct exofs_sb_info *sbi, unsigned numdevs,
+                     struct exofs_dev **peds)
+{
+       struct __alloc_ore_devs_and_exofs_devs {
+               /* Twice bigger table: See exofs_init_comps() and comment at
+                * exofs_read_lookup_dev_table()
+                */
+               struct ore_dev *oreds[numdevs * 2 - 1];
+               struct exofs_dev eds[numdevs];
+       } *aoded;
+       struct exofs_dev *eds;
+       unsigned i;
+
+       aoded = kzalloc(sizeof(*aoded), GFP_KERNEL);
+       if (unlikely(!aoded)) {
+               EXOFS_ERR("ERROR: failed allocating Device array[%d]\n",
+                         numdevs);
+               return -ENOMEM;
+       }
+
+       sbi->oc.ods = aoded->oreds;
+       *peds = eds = aoded->eds;
+       for (i = 0; i < numdevs; ++i)
+               aoded->oreds[i] = &eds[i].ored;
+       return 0;
+}
+
+static int exofs_read_lookup_dev_table(struct exofs_sb_info *sbi,
+                                      struct osd_dev *fscb_od,
+                                      unsigned table_count)
+{
+       struct ore_comp comp;
+       struct exofs_device_table *dt;
+       struct exofs_dev *eds;
+       unsigned table_bytes = table_count * sizeof(dt->dt_dev_table[0]) +
+                                            sizeof(*dt);
+       unsigned numdevs, i;
+       int ret;
+
+       dt = kmalloc(table_bytes, GFP_KERNEL);
+       if (unlikely(!dt)) {
+               EXOFS_ERR("ERROR: allocating %x bytes for device table\n",
+                         table_bytes);
+               return -ENOMEM;
+       }
+
+       sbi->oc.numdevs = 0;
+
+       comp.obj.partition = sbi->one_comp.obj.partition;
+       comp.obj.id = EXOFS_DEVTABLE_ID;
+       exofs_make_credential(comp.cred, &comp.obj);
+
+       ret = exofs_read_kern(fscb_od, comp.cred, &comp.obj, 0, dt,
+                             table_bytes);
+       if (unlikely(ret)) {
+               EXOFS_ERR("ERROR: reading device table\n");
+               goto out;
+       }
+
+       numdevs = le64_to_cpu(dt->dt_num_devices);
+       if (unlikely(!numdevs)) {
+               ret = -EINVAL;
+               goto out;
+       }
+       WARN_ON(table_count != numdevs);
+
+       ret = _read_and_match_data_map(sbi, numdevs, dt);
+       if (unlikely(ret))
+               goto out;
+
+       ret = __alloc_dev_table(sbi, numdevs, &eds);
+       if (unlikely(ret))
+               goto out;
+       /* exofs round-robins the device table view according to inode
+        * number. We hold a: twice bigger table hence inodes can point
+        * to any device and have a sequential view of the table
+        * starting at this device. See exofs_init_comps()
+        */
+       memcpy(&sbi->oc.ods[numdevs], &sbi->oc.ods[0],
+               (numdevs - 1) * sizeof(sbi->oc.ods[0]));
+
+       /* create sysfs subdir under which we put the device table
+        * And cluster layout. A Superblock is identified by the string:
+        *      "dev[0].osdname"_"pid"
+        */
+       exofs_sysfs_sb_add(sbi, &dt->dt_dev_table[0]);
+
+       for (i = 0; i < numdevs; i++) {
+               struct exofs_fscb fscb;
+               struct osd_dev_info odi;
+               struct osd_dev *od;
+
+               if (exofs_devs_2_odi(&dt->dt_dev_table[i], &odi)) {
+                       EXOFS_ERR("ERROR: Read all-zeros device entry\n");
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               printk(KERN_NOTICE "Add device[%d]: osd_name-%s\n",
+                      i, odi.osdname);
+
+               /* the exofs id is currently the table index */
+               eds[i].did = i;
+
+               /* On all devices the device table is identical. The user can
+                * specify any one of the participating devices on the command
+                * line. We always keep them in device-table order.
+                */
+               if (fscb_od && osduld_device_same(fscb_od, &odi)) {
+                       eds[i].ored.od = fscb_od;
+                       ++sbi->oc.numdevs;
+                       fscb_od = NULL;
+                       exofs_sysfs_odev_add(&eds[i], sbi);
+                       continue;
+               }
+
+               od = osduld_info_lookup(&odi);
+               if (IS_ERR(od)) {
+                       ret = PTR_ERR(od);
+                       EXOFS_ERR("ERROR: device requested is not found "
+                                 "osd_name-%s =>%d\n", odi.osdname, ret);
+                       goto out;
+               }
+
+               eds[i].ored.od = od;
+               ++sbi->oc.numdevs;
+
+               /* Read the fscb of the other devices to make sure the FS
+                * partition is there.
+                */
+               ret = exofs_read_kern(od, comp.cred, &comp.obj, 0, &fscb,
+                                     sizeof(fscb));
+               if (unlikely(ret)) {
+                       EXOFS_ERR("ERROR: Malformed participating device "
+                                 "error reading fscb osd_name-%s\n",
+                                 odi.osdname);
+                       goto out;
+               }
+               exofs_sysfs_odev_add(&eds[i], sbi);
+
+               /* TODO: verify other information is correct and FS-uuid
+                *       matches. Benny what did you say about device table
+                *       generation and old devices?
+                */
+       }
+
+out:
+       kfree(dt);
+       if (unlikely(fscb_od && !ret)) {
+                       EXOFS_ERR("ERROR: Bad device-table container device not present\n");
+                       osduld_put_device(fscb_od);
+                       return -EINVAL;
+       }
+       return ret;
+}
+
+/*
+ * Read the superblock from the OSD and fill in the fields
+ */
+static int exofs_fill_super(struct super_block *sb, void *data, int silent)
+{
+       struct inode *root;
+       struct exofs_mountopt *opts = data;
+       struct exofs_sb_info *sbi;      /*extended info                  */
+       struct osd_dev *od;             /* Master device                 */
+       struct exofs_fscb fscb;         /*on-disk superblock info        */
+       struct ore_comp comp;
+       unsigned table_count;
+       int ret;
+
+       sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+       if (!sbi)
+               return -ENOMEM;
+
+       /* use mount options to fill superblock */
+       if (opts->is_osdname) {
+               struct osd_dev_info odi = {.systemid_len = 0};
+
+               odi.osdname_len = strlen(opts->dev_name);
+               odi.osdname = (u8 *)opts->dev_name;
+               od = osduld_info_lookup(&odi);
+               kfree(opts->dev_name);
+               opts->dev_name = NULL;
+       } else {
+               od = osduld_path_lookup(opts->dev_name);
+       }
+       if (IS_ERR(od)) {
+               ret = -EINVAL;
+               goto free_sbi;
+       }
+
+       /* Default layout in case we do not have a device-table */
+       sbi->layout.stripe_unit = PAGE_SIZE;
+       sbi->layout.mirrors_p1 = 1;
+       sbi->layout.group_width = 1;
+       sbi->layout.group_depth = -1;
+       sbi->layout.group_count = 1;
+       sbi->s_timeout = opts->timeout;
+
+       sbi->one_comp.obj.partition = opts->pid;
+       sbi->one_comp.obj.id = 0;
+       exofs_make_credential(sbi->one_comp.cred, &sbi->one_comp.obj);
+       sbi->oc.single_comp = EC_SINGLE_COMP;
+       sbi->oc.comps = &sbi->one_comp;
+
+       /* fill in some other data by hand */
+       memset(sb->s_id, 0, sizeof(sb->s_id));
+       strcpy(sb->s_id, "exofs");
+       sb->s_blocksize = EXOFS_BLKSIZE;
+       sb->s_blocksize_bits = EXOFS_BLKSHIFT;
+       sb->s_maxbytes = MAX_LFS_FILESIZE;
+       sb->s_max_links = EXOFS_LINK_MAX;
+       atomic_set(&sbi->s_curr_pending, 0);
+       sb->s_bdev = NULL;
+       sb->s_dev = 0;
+
+       comp.obj.partition = sbi->one_comp.obj.partition;
+       comp.obj.id = EXOFS_SUPER_ID;
+       exofs_make_credential(comp.cred, &comp.obj);
+
+       ret = exofs_read_kern(od, comp.cred, &comp.obj, 0, &fscb, sizeof(fscb));
+       if (unlikely(ret))
+               goto free_sbi;
+
+       sb->s_magic = le16_to_cpu(fscb.s_magic);
+       /* NOTE: we read below to be backward compatible with old versions */
+       sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
+       sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
+
+       /* make sure what we read from the object store is correct */
+       if (sb->s_magic != EXOFS_SUPER_MAGIC) {
+               if (!silent)
+                       EXOFS_ERR("ERROR: Bad magic value\n");
+               ret = -EINVAL;
+               goto free_sbi;
+       }
+       if (le32_to_cpu(fscb.s_version) > EXOFS_FSCB_VER) {
+               EXOFS_ERR("ERROR: Bad FSCB version expected-%d got-%d\n",
+                         EXOFS_FSCB_VER, le32_to_cpu(fscb.s_version));
+               ret = -EINVAL;
+               goto free_sbi;
+       }
+
+       /* start generation numbers from a random point */
+       get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+       spin_lock_init(&sbi->s_next_gen_lock);
+
+       table_count = le64_to_cpu(fscb.s_dev_table_count);
+       if (table_count) {
+               ret = exofs_read_lookup_dev_table(sbi, od, table_count);
+               if (unlikely(ret))
+                       goto free_sbi;
+       } else {
+               struct exofs_dev *eds;
+
+               ret = __alloc_dev_table(sbi, 1, &eds);
+               if (unlikely(ret))
+                       goto free_sbi;
+
+               ore_comp_set_dev(&sbi->oc, 0, od);
+               sbi->oc.numdevs = 1;
+       }
+
+       __sbi_read_stats(sbi);
+
+       /* set up operation vectors */
+       sbi->bdi.ra_pages = __ra_pages(&sbi->layout);
+       sb->s_bdi = &sbi->bdi;
+       sb->s_fs_info = sbi;
+       sb->s_op = &exofs_sops;
+       sb->s_export_op = &exofs_export_ops;
+       root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
+       if (IS_ERR(root)) {
+               EXOFS_ERR("ERROR: exofs_iget failed\n");
+               ret = PTR_ERR(root);
+               goto free_sbi;
+       }
+       sb->s_root = d_make_root(root);
+       if (!sb->s_root) {
+               EXOFS_ERR("ERROR: get root inode failed\n");
+               ret = -ENOMEM;
+               goto free_sbi;
+       }
+
+       if (!S_ISDIR(root->i_mode)) {
+               dput(sb->s_root);
+               sb->s_root = NULL;
+               EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
+                      root->i_mode);
+               ret = -EINVAL;
+               goto free_sbi;
+       }
+
+       ret = bdi_setup_and_register(&sbi->bdi, "exofs");
+       if (ret) {
+               EXOFS_DBGMSG("Failed to bdi_setup_and_register\n");
+               dput(sb->s_root);
+               sb->s_root = NULL;
+               goto free_sbi;
+       }
+
+       exofs_sysfs_dbg_print();
+       _exofs_print_device("Mounting", opts->dev_name,
+                           ore_comp_dev(&sbi->oc, 0),
+                           sbi->one_comp.obj.partition);
+       return 0;
+
+free_sbi:
+       EXOFS_ERR("Unable to mount exofs on %s pid=0x%llx err=%d\n",
+                 opts->dev_name, sbi->one_comp.obj.partition, ret);
+       exofs_free_sbi(sbi);
+       return ret;
+}
+
+/*
+ * Set up the superblock (calls exofs_fill_super eventually)
+ */
+static struct dentry *exofs_mount(struct file_system_type *type,
+                         int flags, const char *dev_name,
+                         void *data)
+{
+       struct exofs_mountopt opts;
+       int ret;
+
+       ret = parse_options(data, &opts);
+       if (ret)
+               return ERR_PTR(ret);
+
+       if (!opts.dev_name)
+               opts.dev_name = dev_name;
+       return mount_nodev(type, flags, &opts, exofs_fill_super);
+}
+
+/*
+ * Return information about the file system state in the buffer.  This is used
+ * by the 'df' command, for example.
+ */
+static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+       struct super_block *sb = dentry->d_sb;
+       struct exofs_sb_info *sbi = sb->s_fs_info;
+       struct ore_io_state *ios;
+       struct osd_attr attrs[] = {
+               ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
+                       OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
+               ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
+                       OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
+       };
+       uint64_t capacity = ULLONG_MAX;
+       uint64_t used = ULLONG_MAX;
+       int ret;
+
+       ret = ore_get_io_state(&sbi->layout, &sbi->oc, &ios);
+       if (ret) {
+               EXOFS_DBGMSG("ore_get_io_state failed.\n");
+               return ret;
+       }
+
+       ios->in_attr = attrs;
+       ios->in_attr_len = ARRAY_SIZE(attrs);
+
+       ret = ore_read(ios);
+       if (unlikely(ret))
+               goto out;
+
+       ret = extract_attr_from_ios(ios, &attrs[0]);
+       if (likely(!ret)) {
+               capacity = get_unaligned_be64(attrs[0].val_ptr);
+               if (unlikely(!capacity))
+                       capacity = ULLONG_MAX;
+       } else
+               EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
+
+       ret = extract_attr_from_ios(ios, &attrs[1]);
+       if (likely(!ret))
+               used = get_unaligned_be64(attrs[1].val_ptr);
+       else
+               EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
+
+       /* fill in the stats buffer */
+       buf->f_type = EXOFS_SUPER_MAGIC;
+       buf->f_bsize = EXOFS_BLKSIZE;
+       buf->f_blocks = capacity >> 9;
+       buf->f_bfree = (capacity - used) >> 9;
+       buf->f_bavail = buf->f_bfree;
+       buf->f_files = sbi->s_numfiles;
+       buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
+       buf->f_namelen = EXOFS_NAME_LEN;
+
+out:
+       ore_put_io_state(ios);
+       return ret;
+}
+
+static const struct super_operations exofs_sops = {
+       .alloc_inode    = exofs_alloc_inode,
+       .destroy_inode  = exofs_destroy_inode,
+       .write_inode    = exofs_write_inode,
+       .evict_inode    = exofs_evict_inode,
+       .put_super      = exofs_put_super,
+       .sync_fs        = exofs_sync_fs,
+       .statfs         = exofs_statfs,
+};
+
+/******************************************************************************
+ * EXPORT OPERATIONS
+ *****************************************************************************/
+
+static struct dentry *exofs_get_parent(struct dentry *child)
+{
+       unsigned long ino = exofs_parent_ino(child);
+
+       if (!ino)
+               return ERR_PTR(-ESTALE);
+
+       return d_obtain_alias(exofs_iget(d_inode(child)->i_sb, ino));
+}
+
+static struct inode *exofs_nfs_get_inode(struct super_block *sb,
+               u64 ino, u32 generation)
+{
+       struct inode *inode;
+
+       inode = exofs_iget(sb, ino);
+       if (IS_ERR(inode))
+               return ERR_CAST(inode);
+       if (generation && inode->i_generation != generation) {
+               /* we didn't find the right inode.. */
+               iput(inode);
+               return ERR_PTR(-ESTALE);
+       }
+       return inode;
+}
+
+static struct dentry *exofs_fh_to_dentry(struct super_block *sb,
+                               struct fid *fid, int fh_len, int fh_type)
+{
+       return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+                                   exofs_nfs_get_inode);
+}
+
+static struct dentry *exofs_fh_to_parent(struct super_block *sb,
+                               struct fid *fid, int fh_len, int fh_type)
+{
+       return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+                                   exofs_nfs_get_inode);
+}
+
+static const struct export_operations exofs_export_ops = {
+       .fh_to_dentry = exofs_fh_to_dentry,
+       .fh_to_parent = exofs_fh_to_parent,
+       .get_parent = exofs_get_parent,
+};
+
+/******************************************************************************
+ * INSMOD/RMMOD
+ *****************************************************************************/
+
+/*
+ * struct that describes this file system
+ */
+static struct file_system_type exofs_type = {
+       .owner          = THIS_MODULE,
+       .name           = "exofs",
+       .mount          = exofs_mount,
+       .kill_sb        = generic_shutdown_super,
+};
+MODULE_ALIAS_FS("exofs");
+
+static int __init init_exofs(void)
+{
+       int err;
+
+       err = init_inodecache();
+       if (err)
+               goto out;
+
+       err = register_filesystem(&exofs_type);
+       if (err)
+               goto out_d;
+
+       /* We don't fail if sysfs creation failed */
+       exofs_sysfs_init();
+
+       return 0;
+out_d:
+       destroy_inodecache();
+out:
+       return err;
+}
+
+static void __exit exit_exofs(void)
+{
+       exofs_sysfs_uninit();
+       unregister_filesystem(&exofs_type);
+       destroy_inodecache();
+}
+
+MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
+MODULE_DESCRIPTION("exofs");
+MODULE_LICENSE("GPL");
+
+module_init(init_exofs)
+module_exit(exit_exofs)