]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/fs.c
Update bcachefs sources to 481b5f343248 bcachefs: Better error messages for missing...
[bcachefs-tools-debian] / libbcachefs / fs.c
index b1bbec3f96bd3c5360b8b3b7eb9bddab10857736..ec419b8e2c43123b42e0d84c837611fc5f6e2314 100644 (file)
@@ -8,17 +8,22 @@
 #include "buckets.h"
 #include "chardev.h"
 #include "dirent.h"
+#include "errcode.h"
 #include "extents.h"
 #include "fs.h"
 #include "fs-common.h"
 #include "fs-io.h"
 #include "fs-ioctl.h"
+#include "fs-io-buffered.h"
+#include "fs-io-direct.h"
+#include "fs-io-pagecache.h"
 #include "fsck.h"
 #include "inode.h"
-#include "io.h"
+#include "io_read.h"
 #include "journal.h"
 #include "keylist.h"
 #include "quota.h"
+#include "snapshot.h"
 #include "super.h"
 #include "xattr.h"
 
 #include <linux/exportfs.h>
 #include <linux/fiemap.h>
 #include <linux/module.h>
+#include <linux/pagemap.h>
 #include <linux/posix_acl.h>
 #include <linux/random.h>
+#include <linux/seq_file.h>
 #include <linux/statfs.h>
+#include <linux/string.h>
 #include <linux/xattr.h>
 
 static struct kmem_cache *bch2_inode_cache;
 
-static void bch2_vfs_inode_init(struct bch_fs *,
+static void bch2_vfs_inode_init(struct btree_trans *, subvol_inum,
                                struct bch_inode_info *,
-                               struct bch_inode_unpacked *);
+                               struct bch_inode_unpacked *,
+                               struct bch_subvolume *);
 
-static void journal_seq_copy(struct bch_fs *c,
-                            struct bch_inode_info *dst,
-                            u64 journal_seq)
-{
-       /*
-        * atomic64_cmpxchg has a fallback for archs that don't support it,
-        * cmpxchg does not:
-        */
-       atomic64_t *dst_seq = (void *) &dst->ei_journal_seq;
-       u64 old, v = READ_ONCE(dst->ei_journal_seq);
-
-       do {
-               old = v;
-
-               if (old >= journal_seq)
-                       break;
-       } while ((v = atomic64_cmpxchg(dst_seq, old, journal_seq)) != old);
-
-       bch2_journal_set_has_inum(&c->journal, dst->v.i_ino, journal_seq);
-}
-
-static void __pagecache_lock_put(struct pagecache_lock *lock, long i)
-{
-       BUG_ON(atomic_long_read(&lock->v) == 0);
-
-       if (atomic_long_sub_return_release(i, &lock->v) == 0)
-               wake_up_all(&lock->wait);
-}
-
-static bool __pagecache_lock_tryget(struct pagecache_lock *lock, long i)
-{
-       long v = atomic_long_read(&lock->v), old;
-
-       do {
-               old = v;
-
-               if (i > 0 ? v < 0 : v > 0)
-                       return false;
-       } while ((v = atomic_long_cmpxchg_acquire(&lock->v,
-                                       old, old + i)) != old);
-       return true;
-}
-
-static void __pagecache_lock_get(struct pagecache_lock *lock, long i)
-{
-       wait_event(lock->wait, __pagecache_lock_tryget(lock, i));
-}
-
-void bch2_pagecache_add_put(struct pagecache_lock *lock)
-{
-       __pagecache_lock_put(lock, 1);
-}
-
-bool bch2_pagecache_add_tryget(struct pagecache_lock *lock)
-{
-       return __pagecache_lock_tryget(lock, 1);
-}
-
-void bch2_pagecache_add_get(struct pagecache_lock *lock)
-{
-       __pagecache_lock_get(lock, 1);
-}
-
-void bch2_pagecache_block_put(struct pagecache_lock *lock)
-{
-       __pagecache_lock_put(lock, -1);
-}
-
-void bch2_pagecache_block_get(struct pagecache_lock *lock)
-{
-       __pagecache_lock_get(lock, -1);
-}
-
-void bch2_inode_update_after_write(struct bch_fs *c,
+void bch2_inode_update_after_write(struct btree_trans *trans,
                                   struct bch_inode_info *inode,
                                   struct bch_inode_unpacked *bi,
                                   unsigned fields)
 {
+       struct bch_fs *c = trans->c;
+
+       BUG_ON(bi->bi_inum != inode->v.i_ino);
+
+       bch2_assert_pos_locked(trans, BTREE_ID_inodes,
+                              POS(0, bi->bi_inum),
+                              c->opts.inodes_use_key_cache);
+
        set_nlink(&inode->v, bch2_inode_nlink_get(bi));
        i_uid_write(&inode->v, bi->bi_uid);
        i_gid_write(&inode->v, bi->bi_gid);
        inode->v.i_mode = bi->bi_mode;
 
        if (fields & ATTR_ATIME)
-               inode->v.i_atime = bch2_time_to_timespec(c, bi->bi_atime);
+               inode_set_atime_to_ts(&inode->v, bch2_time_to_timespec(c, bi->bi_atime));
        if (fields & ATTR_MTIME)
-               inode->v.i_mtime = bch2_time_to_timespec(c, bi->bi_mtime);
+               inode_set_mtime_to_ts(&inode->v, bch2_time_to_timespec(c, bi->bi_mtime));
        if (fields & ATTR_CTIME)
-               inode->v.i_ctime = bch2_time_to_timespec(c, bi->bi_ctime);
+               inode_set_ctime_to_ts(&inode->v, bch2_time_to_timespec(c, bi->bi_ctime));
 
        inode->ei_inode         = *bi;
 
@@ -138,38 +82,37 @@ int __must_check bch2_write_inode(struct bch_fs *c,
                                  inode_set_fn set,
                                  void *p, unsigned fields)
 {
-       struct btree_trans trans;
-       struct btree_iter *iter;
+       struct btree_trans *trans = bch2_trans_get(c);
+       struct btree_iter iter = { NULL };
        struct bch_inode_unpacked inode_u;
        int ret;
-
-       bch2_trans_init(&trans, c, 0, 256);
 retry:
-       bch2_trans_begin(&trans);
-
-       iter = bch2_inode_peek(&trans, &inode_u, inode->v.i_ino,
-                              BTREE_ITER_INTENT);
-       ret   = PTR_ERR_OR_ZERO(iter) ?:
-               (set ? set(inode, &inode_u, p) : 0) ?:
-               bch2_inode_write(&trans, iter, &inode_u) ?:
-               bch2_trans_commit(&trans, NULL,
-                                 &inode->ei_journal_seq,
-                                 BTREE_INSERT_NOUNLOCK|
-                                 BTREE_INSERT_NOFAIL);
+       bch2_trans_begin(trans);
+
+       ret   = bch2_inode_peek(trans, &iter, &inode_u, inode_inum(inode),
+                               BTREE_ITER_INTENT) ?:
+               (set ? set(trans, inode, &inode_u, p) : 0) ?:
+               bch2_inode_write(trans, &iter, &inode_u) ?:
+               bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
 
        /*
         * the btree node lock protects inode->ei_inode, not ei_update_lock;
         * this is important for inode updates via bchfs_write_index_update
         */
        if (!ret)
-               bch2_inode_update_after_write(c, inode, &inode_u, fields);
+               bch2_inode_update_after_write(trans, inode, &inode_u, fields);
 
-       bch2_trans_iter_put(&trans, iter);
+       bch2_trans_iter_exit(trans, &iter);
 
-       if (ret == -EINTR)
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                goto retry;
 
-       bch2_trans_exit(&trans);
+       bch2_fs_fatal_err_on(bch2_err_matches(ret, ENOENT), c,
+                            "inode %u:%llu not found when updating",
+                            inode_inum(inode).subvol,
+                            inode_inum(inode).inum);
+
+       bch2_trans_put(trans);
        return ret < 0 ? ret : 0;
 }
 
@@ -208,51 +151,86 @@ int bch2_fs_quota_transfer(struct bch_fs *c,
        return ret;
 }
 
-struct inode *bch2_vfs_inode_get(struct bch_fs *c, u64 inum)
+static int bch2_iget5_test(struct inode *vinode, void *p)
+{
+       struct bch_inode_info *inode = to_bch_ei(vinode);
+       subvol_inum *inum = p;
+
+       return inode->ei_subvol == inum->subvol &&
+               inode->ei_inode.bi_inum == inum->inum;
+}
+
+static int bch2_iget5_set(struct inode *vinode, void *p)
+{
+       struct bch_inode_info *inode = to_bch_ei(vinode);
+       subvol_inum *inum = p;
+
+       inode->v.i_ino          = inum->inum;
+       inode->ei_subvol        = inum->subvol;
+       inode->ei_inode.bi_inum = inum->inum;
+       return 0;
+}
+
+static unsigned bch2_inode_hash(subvol_inum inum)
+{
+       return jhash_3words(inum.subvol, inum.inum >> 32, inum.inum, JHASH_INITVAL);
+}
+
+struct inode *bch2_vfs_inode_get(struct bch_fs *c, subvol_inum inum)
 {
        struct bch_inode_unpacked inode_u;
        struct bch_inode_info *inode;
+       struct btree_trans *trans;
+       struct bch_subvolume subvol;
        int ret;
 
-       inode = to_bch_ei(iget_locked(c->vfs_sb, inum));
+       inode = to_bch_ei(iget5_locked(c->vfs_sb,
+                                      bch2_inode_hash(inum),
+                                      bch2_iget5_test,
+                                      bch2_iget5_set,
+                                      &inum));
        if (unlikely(!inode))
                return ERR_PTR(-ENOMEM);
        if (!(inode->v.i_state & I_NEW))
                return &inode->v;
 
-       ret = bch2_inode_find_by_inum(c, inum, &inode_u);
+       trans = bch2_trans_get(c);
+       ret = lockrestart_do(trans,
+               bch2_subvolume_get(trans, inum.subvol, true, 0, &subvol) ?:
+               bch2_inode_find_by_inum_trans(trans, inum, &inode_u));
+
+       if (!ret)
+               bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
+       bch2_trans_put(trans);
+
        if (ret) {
                iget_failed(&inode->v);
-               return ERR_PTR(ret);
+               return ERR_PTR(bch2_err_class(ret));
        }
 
-       bch2_vfs_inode_init(c, inode, &inode_u);
-
-       inode->ei_journal_seq = bch2_inode_journal_seq(&c->journal, inum);
+       mutex_lock(&c->vfs_inodes_lock);
+       list_add(&inode->ei_vfs_inode_list, &c->vfs_inodes_list);
+       mutex_unlock(&c->vfs_inodes_lock);
 
        unlock_new_inode(&inode->v);
 
        return &inode->v;
 }
 
-static int inum_test(struct inode *inode, void *p)
-{
-       unsigned long *ino = p;
-
-       return *ino == inode->i_ino;
-}
-
-static struct bch_inode_info *
-__bch2_create(struct bch_inode_info *dir, struct dentry *dentry,
-             umode_t mode, dev_t rdev, bool tmpfile)
+struct bch_inode_info *
+__bch2_create(struct mnt_idmap *idmap,
+             struct bch_inode_info *dir, struct dentry *dentry,
+             umode_t mode, dev_t rdev, subvol_inum snapshot_src,
+             unsigned flags)
 {
        struct bch_fs *c = dir->v.i_sb->s_fs_info;
-       struct user_namespace *ns = dir->v.i_sb->s_user_ns;
-       struct btree_trans trans;
+       struct btree_trans *trans;
        struct bch_inode_unpacked dir_u;
        struct bch_inode_info *inode, *old;
        struct bch_inode_unpacked inode_u;
        struct posix_acl *default_acl = NULL, *acl = NULL;
+       subvol_inum inum;
+       struct bch_subvolume subvol;
        u64 journal_seq = 0;
        int ret;
 
@@ -273,45 +251,50 @@ __bch2_create(struct bch_inode_info *dir, struct dentry *dentry,
 
        bch2_inode_init_early(c, &inode_u);
 
-       if (!tmpfile)
+       if (!(flags & BCH_CREATE_TMPFILE))
                mutex_lock(&dir->ei_update_lock);
 
-       bch2_trans_init(&trans, c, 8,
-                       2048 + (!tmpfile ? dentry->d_name.len : 0));
+       trans = bch2_trans_get(c);
 retry:
-       bch2_trans_begin(&trans);
-
-       ret   = bch2_create_trans(&trans, dir->v.i_ino, &dir_u, &inode_u,
-                                 !tmpfile ? &dentry->d_name : NULL,
-                                 from_kuid(ns, current_fsuid()),
-                                 from_kgid(ns, current_fsgid()),
+       bch2_trans_begin(trans);
+
+       ret   = bch2_subvol_is_ro_trans(trans, dir->ei_subvol) ?:
+               bch2_create_trans(trans,
+                                 inode_inum(dir), &dir_u, &inode_u,
+                                 !(flags & BCH_CREATE_TMPFILE)
+                                 ? &dentry->d_name : NULL,
+                                 from_kuid(i_user_ns(&dir->v), current_fsuid()),
+                                 from_kgid(i_user_ns(&dir->v), current_fsgid()),
                                  mode, rdev,
-                                 default_acl, acl) ?:
+                                 default_acl, acl, snapshot_src, flags) ?:
                bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, 1,
                                KEY_TYPE_QUOTA_PREALLOC);
        if (unlikely(ret))
                goto err_before_quota;
 
-       ret   = bch2_trans_commit(&trans, NULL, &journal_seq,
-                                 BTREE_INSERT_NOUNLOCK);
+       inum.subvol = inode_u.bi_subvol ?: dir->ei_subvol;
+       inum.inum = inode_u.bi_inum;
+
+       ret   = bch2_subvolume_get(trans, inum.subvol, true,
+                                  BTREE_ITER_WITH_UPDATES, &subvol) ?:
+               bch2_trans_commit(trans, NULL, &journal_seq, 0);
        if (unlikely(ret)) {
                bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, -1,
                                KEY_TYPE_QUOTA_WARN);
 err_before_quota:
-               if (ret == -EINTR)
+               if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                        goto retry;
                goto err_trans;
        }
 
-       if (!tmpfile) {
-               bch2_inode_update_after_write(c, dir, &dir_u,
+       if (!(flags & BCH_CREATE_TMPFILE)) {
+               bch2_inode_update_after_write(trans, dir, &dir_u,
                                              ATTR_MTIME|ATTR_CTIME);
-               journal_seq_copy(c, dir, journal_seq);
                mutex_unlock(&dir->ei_update_lock);
        }
 
-       bch2_vfs_inode_init(c, inode, &inode_u);
-       journal_seq_copy(c, inode, journal_seq);
+       bch2_iget5_set(&inode->v, &inum);
+       bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
 
        set_cached_acl(&inode->v, ACL_TYPE_ACCESS, acl);
        set_cached_acl(&inode->v, ACL_TYPE_DEFAULT, default_acl);
@@ -323,8 +306,12 @@ err_before_quota:
         */
 
        inode->v.i_state |= I_CREATING;
-       old = to_bch_ei(inode_insert5(&inode->v, inode->v.i_ino,
-                                     inum_test, NULL, &inode->v.i_ino));
+
+       old = to_bch_ei(inode_insert5(&inode->v,
+                                     bch2_inode_hash(inum),
+                                     bch2_iget5_test,
+                                     bch2_iget5_set,
+                                     &inum));
        BUG_ON(!old);
 
        if (unlikely(old != inode)) {
@@ -332,12 +319,14 @@ err_before_quota:
                 * We raced, another process pulled the new inode into cache
                 * before us:
                 */
-               journal_seq_copy(c, old, journal_seq);
                make_bad_inode(&inode->v);
                iput(&inode->v);
 
                inode = old;
        } else {
+               mutex_lock(&c->vfs_inodes_lock);
+               list_add(&inode->ei_vfs_inode_list, &c->vfs_inodes_list);
+               mutex_unlock(&c->vfs_inodes_lock);
                /*
                 * we really don't want insert_inode_locked2() to be setting
                 * I_NEW...
@@ -345,16 +334,16 @@ err_before_quota:
                unlock_new_inode(&inode->v);
        }
 
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
 err:
        posix_acl_release(default_acl);
        posix_acl_release(acl);
        return inode;
 err_trans:
-       if (!tmpfile)
+       if (!(flags & BCH_CREATE_TMPFILE))
                mutex_unlock(&dir->ei_update_lock);
 
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
        make_bad_inode(&inode->v);
        iput(&inode->v);
        inode = ERR_PTR(ret);
@@ -370,34 +359,38 @@ static struct dentry *bch2_lookup(struct inode *vdir, struct dentry *dentry,
        struct bch_inode_info *dir = to_bch_ei(vdir);
        struct bch_hash_info hash = bch2_hash_info_init(c, &dir->ei_inode);
        struct inode *vinode = NULL;
-       u64 inum;
+       subvol_inum inum = { .subvol = 1 };
+       int ret;
 
-       inum = bch2_dirent_lookup(c, dir->v.i_ino, &hash,
-                                 &dentry->d_name);
+       ret = bch2_dirent_lookup(c, inode_inum(dir), &hash,
+                                &dentry->d_name, &inum);
 
-       if (inum)
+       if (!ret)
                vinode = bch2_vfs_inode_get(c, inum);
 
        return d_splice_alias(vinode, dentry);
 }
 
-static int bch2_mknod(struct inode *vdir, struct dentry *dentry,
+static int bch2_mknod(struct mnt_idmap *idmap,
+                     struct inode *vdir, struct dentry *dentry,
                      umode_t mode, dev_t rdev)
 {
        struct bch_inode_info *inode =
-               __bch2_create(to_bch_ei(vdir), dentry, mode, rdev, false);
+               __bch2_create(idmap, to_bch_ei(vdir), dentry, mode, rdev,
+                             (subvol_inum) { 0 }, 0);
 
        if (IS_ERR(inode))
-               return PTR_ERR(inode);
+               return bch2_err_class(PTR_ERR(inode));
 
        d_instantiate(dentry, &inode->v);
        return 0;
 }
 
-static int bch2_create(struct inode *vdir, struct dentry *dentry,
+static int bch2_create(struct mnt_idmap *idmap,
+                      struct inode *vdir, struct dentry *dentry,
                       umode_t mode, bool excl)
 {
-       return bch2_mknod(vdir, dentry, mode|S_IFREG, 0);
+       return bch2_mknod(idmap, vdir, dentry, mode|S_IFREG, 0);
 }
 
 static int __bch2_link(struct bch_fs *c,
@@ -405,30 +398,25 @@ static int __bch2_link(struct bch_fs *c,
                       struct bch_inode_info *dir,
                       struct dentry *dentry)
 {
-       struct btree_trans trans;
+       struct btree_trans *trans = bch2_trans_get(c);
        struct bch_inode_unpacked dir_u, inode_u;
        int ret;
 
        mutex_lock(&inode->ei_update_lock);
-       bch2_trans_init(&trans, c, 4, 1024);
 
-       ret = __bch2_trans_do(&trans, NULL, &inode->ei_journal_seq,
-                             BTREE_INSERT_NOUNLOCK,
-                       bch2_link_trans(&trans,
-                                       dir->v.i_ino,
-                                       inode->v.i_ino, &dir_u, &inode_u,
+       ret = commit_do(trans, NULL, NULL, 0,
+                       bch2_link_trans(trans,
+                                       inode_inum(dir),   &dir_u,
+                                       inode_inum(inode), &inode_u,
                                        &dentry->d_name));
 
        if (likely(!ret)) {
-               BUG_ON(inode_u.bi_inum != inode->v.i_ino);
-
-               journal_seq_copy(c, inode, dir->ei_journal_seq);
-               bch2_inode_update_after_write(c, dir, &dir_u,
+               bch2_inode_update_after_write(trans, dir, &dir_u,
                                              ATTR_MTIME|ATTR_CTIME);
-               bch2_inode_update_after_write(c, inode, &inode_u, ATTR_CTIME);
+               bch2_inode_update_after_write(trans, inode, &inode_u, ATTR_CTIME);
        }
 
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
        mutex_unlock(&inode->ei_update_lock);
        return ret;
 }
@@ -443,7 +431,9 @@ static int bch2_link(struct dentry *old_dentry, struct inode *vdir,
 
        lockdep_assert_held(&inode->v.i_rwsem);
 
-       ret = __bch2_link(c, inode, dir, dentry);
+       ret   = bch2_subvol_is_ro(c, dir->ei_subvol) ?:
+               bch2_subvol_is_ro(c, inode->ei_subvol) ?:
+               __bch2_link(c, inode, dir, dentry);
        if (unlikely(ret))
                return ret;
 
@@ -452,51 +442,67 @@ static int bch2_link(struct dentry *old_dentry, struct inode *vdir,
        return 0;
 }
 
-static int bch2_unlink(struct inode *vdir, struct dentry *dentry)
+int __bch2_unlink(struct inode *vdir, struct dentry *dentry,
+                 bool deleting_snapshot)
 {
        struct bch_fs *c = vdir->i_sb->s_fs_info;
        struct bch_inode_info *dir = to_bch_ei(vdir);
        struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
        struct bch_inode_unpacked dir_u, inode_u;
-       struct btree_trans trans;
+       struct btree_trans *trans = bch2_trans_get(c);
        int ret;
 
        bch2_lock_inodes(INODE_UPDATE_LOCK, dir, inode);
-       bch2_trans_init(&trans, c, 4, 1024);
 
-       ret = __bch2_trans_do(&trans, NULL, &dir->ei_journal_seq,
-                             BTREE_INSERT_NOUNLOCK|
-                             BTREE_INSERT_NOFAIL,
-                       bch2_unlink_trans(&trans,
-                                         dir->v.i_ino, &dir_u,
-                                         &inode_u, &dentry->d_name));
+       ret = commit_do(trans, NULL, NULL,
+                       BCH_TRANS_COMMIT_no_enospc,
+               bch2_unlink_trans(trans,
+                                 inode_inum(dir), &dir_u,
+                                 &inode_u, &dentry->d_name,
+                                 deleting_snapshot));
+       if (unlikely(ret))
+               goto err;
 
-       if (likely(!ret)) {
-               BUG_ON(inode_u.bi_inum != inode->v.i_ino);
+       bch2_inode_update_after_write(trans, dir, &dir_u,
+                                     ATTR_MTIME|ATTR_CTIME);
+       bch2_inode_update_after_write(trans, inode, &inode_u,
+                                     ATTR_MTIME);
 
-               journal_seq_copy(c, inode, dir->ei_journal_seq);
-               bch2_inode_update_after_write(c, dir, &dir_u,
-                                             ATTR_MTIME|ATTR_CTIME);
-               bch2_inode_update_after_write(c, inode, &inode_u,
-                                             ATTR_MTIME);
+       if (inode_u.bi_subvol) {
+               /*
+                * Subvolume deletion is asynchronous, but we still want to tell
+                * the VFS that it's been deleted here:
+                */
+               set_nlink(&inode->v, 0);
        }
-
-       bch2_trans_exit(&trans);
+err:
        bch2_unlock_inodes(INODE_UPDATE_LOCK, dir, inode);
+       bch2_trans_put(trans);
 
        return ret;
 }
 
-static int bch2_symlink(struct inode *vdir, struct dentry *dentry,
+static int bch2_unlink(struct inode *vdir, struct dentry *dentry)
+{
+       struct bch_inode_info *dir= to_bch_ei(vdir);
+       struct bch_fs *c = dir->v.i_sb->s_fs_info;
+
+       return bch2_subvol_is_ro(c, dir->ei_subvol) ?:
+               __bch2_unlink(vdir, dentry, false);
+}
+
+static int bch2_symlink(struct mnt_idmap *idmap,
+                       struct inode *vdir, struct dentry *dentry,
                        const char *symname)
 {
        struct bch_fs *c = vdir->i_sb->s_fs_info;
        struct bch_inode_info *dir = to_bch_ei(vdir), *inode;
        int ret;
 
-       inode = __bch2_create(dir, dentry, S_IFLNK|S_IRWXUGO, 0, true);
-       if (unlikely(IS_ERR(inode)))
-               return PTR_ERR(inode);
+       inode = __bch2_create(idmap, dir, dentry, S_IFLNK|S_IRWXUGO, 0,
+                             (subvol_inum) { 0 }, BCH_CREATE_TMPFILE);
+       if (IS_ERR(inode))
+               return bch2_err_class(PTR_ERR(inode));
 
        inode_lock(&inode->v);
        ret = page_symlink(&inode->v, symname, strlen(symname) + 1);
@@ -509,8 +515,6 @@ static int bch2_symlink(struct inode *vdir, struct dentry *dentry,
        if (unlikely(ret))
                goto err;
 
-       journal_seq_copy(c, dir, inode->ei_journal_seq);
-
        ret = __bch2_link(c, inode, dir, dentry);
        if (unlikely(ret))
                goto err;
@@ -522,12 +526,14 @@ err:
        return ret;
 }
 
-static int bch2_mkdir(struct inode *vdir, struct dentry *dentry, umode_t mode)
+static int bch2_mkdir(struct mnt_idmap *idmap,
+                     struct inode *vdir, struct dentry *dentry, umode_t mode)
 {
-       return bch2_mknod(vdir, dentry, mode|S_IFDIR, 0);
+       return bch2_mknod(idmap, vdir, dentry, mode|S_IFDIR, 0);
 }
 
-static int bch2_rename2(struct inode *src_vdir, struct dentry *src_dentry,
+static int bch2_rename2(struct mnt_idmap *idmap,
+                       struct inode *src_vdir, struct dentry *src_dentry,
                        struct inode *dst_vdir, struct dentry *dst_dentry,
                        unsigned flags)
 {
@@ -538,12 +544,11 @@ static int bch2_rename2(struct inode *src_vdir, struct dentry *src_dentry,
        struct bch_inode_info *dst_inode = to_bch_ei(dst_dentry->d_inode);
        struct bch_inode_unpacked dst_dir_u, src_dir_u;
        struct bch_inode_unpacked src_inode_u, dst_inode_u;
-       struct btree_trans trans;
+       struct btree_trans *trans;
        enum bch_rename_mode mode = flags & RENAME_EXCHANGE
                ? BCH_RENAME_EXCHANGE
                : dst_dentry->d_inode
                ? BCH_RENAME_OVERWRITE : BCH_RENAME;
-       u64 journal_seq = 0;
        int ret;
 
        if (flags & ~(RENAME_NOREPLACE|RENAME_EXCHANGE))
@@ -556,7 +561,7 @@ static int bch2_rename2(struct inode *src_vdir, struct dentry *src_dentry,
                        return ret;
        }
 
-       bch2_trans_init(&trans, c, 8, 2048);
+       trans = bch2_trans_get(c);
 
        bch2_lock_inodes(INODE_UPDATE_LOCK,
                         src_dir,
@@ -564,6 +569,11 @@ static int bch2_rename2(struct inode *src_vdir, struct dentry *src_dentry,
                         src_inode,
                         dst_inode);
 
+       ret   = bch2_subvol_is_ro_trans(trans, src_dir->ei_subvol) ?:
+               bch2_subvol_is_ro_trans(trans, dst_dir->ei_subvol);
+       if (ret)
+               goto err;
+
        if (inode_attr_changing(dst_dir, src_inode, Inode_opt_project)) {
                ret = bch2_fs_quota_transfer(c, src_inode,
                                             dst_dir->ei_qid,
@@ -583,11 +593,10 @@ static int bch2_rename2(struct inode *src_vdir, struct dentry *src_dentry,
                        goto err;
        }
 
-       ret = __bch2_trans_do(&trans, NULL, &journal_seq,
-                             BTREE_INSERT_NOUNLOCK,
-                       bch2_rename_trans(&trans,
-                                         src_dir->v.i_ino, &src_dir_u,
-                                         dst_dir->v.i_ino, &dst_dir_u,
+       ret = commit_do(trans, NULL, NULL, 0,
+                       bch2_rename_trans(trans,
+                                         inode_inum(src_dir), &src_dir_u,
+                                         inode_inum(dst_dir), &dst_dir_u,
                                          &src_inode_u,
                                          &dst_inode_u,
                                          &src_dentry->d_name,
@@ -600,27 +609,21 @@ static int bch2_rename2(struct inode *src_vdir, struct dentry *src_dentry,
        BUG_ON(dst_inode &&
               dst_inode->v.i_ino != dst_inode_u.bi_inum);
 
-       bch2_inode_update_after_write(c, src_dir, &src_dir_u,
+       bch2_inode_update_after_write(trans, src_dir, &src_dir_u,
                                      ATTR_MTIME|ATTR_CTIME);
-       journal_seq_copy(c, src_dir, journal_seq);
 
-       if (src_dir != dst_dir) {
-               bch2_inode_update_after_write(c, dst_dir, &dst_dir_u,
+       if (src_dir != dst_dir)
+               bch2_inode_update_after_write(trans, dst_dir, &dst_dir_u,
                                              ATTR_MTIME|ATTR_CTIME);
-               journal_seq_copy(c, dst_dir, journal_seq);
-       }
 
-       bch2_inode_update_after_write(c, src_inode, &src_inode_u,
+       bch2_inode_update_after_write(trans, src_inode, &src_inode_u,
                                      ATTR_CTIME);
-       journal_seq_copy(c, src_inode, journal_seq);
 
-       if (dst_inode) {
-               bch2_inode_update_after_write(c, dst_inode, &dst_inode_u,
+       if (dst_inode)
+               bch2_inode_update_after_write(trans, dst_inode, &dst_inode_u,
                                              ATTR_CTIME);
-               journal_seq_copy(c, dst_inode, journal_seq);
-       }
 err:
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
 
        bch2_fs_quota_transfer(c, src_inode,
                               bch_qid(&src_inode->ei_inode),
@@ -641,17 +644,21 @@ err:
        return ret;
 }
 
-void bch2_setattr_copy(struct bch_inode_info *inode,
-                      struct bch_inode_unpacked *bi,
-                      struct iattr *attr)
+static void bch2_setattr_copy(struct mnt_idmap *idmap,
+                             struct bch_inode_info *inode,
+                             struct bch_inode_unpacked *bi,
+                             struct iattr *attr)
 {
        struct bch_fs *c = inode->v.i_sb->s_fs_info;
        unsigned int ia_valid = attr->ia_valid;
 
        if (ia_valid & ATTR_UID)
-               bi->bi_uid = from_kuid(c->vfs_sb->s_user_ns, attr->ia_uid);
+               bi->bi_uid = from_kuid(i_user_ns(&inode->v), attr->ia_uid);
        if (ia_valid & ATTR_GID)
-               bi->bi_gid = from_kgid(c->vfs_sb->s_user_ns, attr->ia_gid);
+               bi->bi_gid = from_kgid(i_user_ns(&inode->v), attr->ia_gid);
+
+       if (ia_valid & ATTR_SIZE)
+               bi->bi_size = attr->ia_size;
 
        if (ia_valid & ATTR_ATIME)
                bi->bi_atime = timespec_to_bch2_time(c, attr->ia_atime);
@@ -667,19 +674,20 @@ void bch2_setattr_copy(struct bch_inode_info *inode,
                        : inode->v.i_gid;
 
                if (!in_group_p(gid) &&
-                   !capable_wrt_inode_uidgid(&inode->v, CAP_FSETID))
+                   !capable_wrt_inode_uidgid(idmap, &inode->v, CAP_FSETID))
                        mode &= ~S_ISGID;
                bi->bi_mode = mode;
        }
 }
 
-static int bch2_setattr_nonsize(struct bch_inode_info *inode,
-                               struct iattr *attr)
+int bch2_setattr_nonsize(struct mnt_idmap *idmap,
+                        struct bch_inode_info *inode,
+                        struct iattr *attr)
 {
        struct bch_fs *c = inode->v.i_sb->s_fs_info;
        struct bch_qid qid;
-       struct btree_trans trans;
-       struct btree_iter *inode_iter;
+       struct btree_trans *trans;
+       struct btree_iter inode_iter = { NULL };
        struct bch_inode_unpacked inode_u;
        struct posix_acl *acl = NULL;
        int ret;
@@ -689,62 +697,61 @@ static int bch2_setattr_nonsize(struct bch_inode_info *inode,
        qid = inode->ei_qid;
 
        if (attr->ia_valid & ATTR_UID)
-               qid.q[QTYP_USR] = from_kuid(&init_user_ns, attr->ia_uid);
+               qid.q[QTYP_USR] = from_kuid(i_user_ns(&inode->v), attr->ia_uid);
 
        if (attr->ia_valid & ATTR_GID)
-               qid.q[QTYP_GRP] = from_kgid(&init_user_ns, attr->ia_gid);
+               qid.q[QTYP_GRP] = from_kgid(i_user_ns(&inode->v), attr->ia_gid);
 
        ret = bch2_fs_quota_transfer(c, inode, qid, ~0,
                                     KEY_TYPE_QUOTA_PREALLOC);
        if (ret)
                goto err;
 
-       bch2_trans_init(&trans, c, 0, 0);
+       trans = bch2_trans_get(c);
 retry:
-       bch2_trans_begin(&trans);
+       bch2_trans_begin(trans);
        kfree(acl);
        acl = NULL;
 
-       inode_iter = bch2_inode_peek(&trans, &inode_u, inode->v.i_ino,
-                                    BTREE_ITER_INTENT);
-       ret = PTR_ERR_OR_ZERO(inode_iter);
+       ret = bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
+                             BTREE_ITER_INTENT);
        if (ret)
                goto btree_err;
 
-       bch2_setattr_copy(inode, &inode_u, attr);
+       bch2_setattr_copy(idmap, inode, &inode_u, attr);
 
        if (attr->ia_valid & ATTR_MODE) {
-               ret = bch2_acl_chmod(&trans, &inode_u, inode_u.bi_mode, &acl);
+               ret = bch2_acl_chmod(trans, inode_inum(inode), &inode_u,
+                                    inode_u.bi_mode, &acl);
                if (ret)
                        goto btree_err;
        }
 
-       ret =   bch2_inode_write(&trans, inode_iter, &inode_u) ?:
-               bch2_trans_commit(&trans, NULL,
-                                 &inode->ei_journal_seq,
-                                 BTREE_INSERT_NOUNLOCK|
-                                 BTREE_INSERT_NOFAIL);
+       ret =   bch2_inode_write(trans, &inode_iter, &inode_u) ?:
+               bch2_trans_commit(trans, NULL, NULL,
+                                 BCH_TRANS_COMMIT_no_enospc);
 btree_err:
-       bch2_trans_iter_put(&trans, inode_iter);
+       bch2_trans_iter_exit(trans, &inode_iter);
 
-       if (ret == -EINTR)
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                goto retry;
        if (unlikely(ret))
                goto err_trans;
 
-       bch2_inode_update_after_write(c, inode, &inode_u, attr->ia_valid);
+       bch2_inode_update_after_write(trans, inode, &inode_u, attr->ia_valid);
 
        if (acl)
                set_cached_acl(&inode->v, ACL_TYPE_ACCESS, acl);
 err_trans:
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
 err:
        mutex_unlock(&inode->ei_update_lock);
 
-       return ret;
+       return bch2_err_class(ret);
 }
 
-static int bch2_getattr(const struct path *path, struct kstat *stat,
+static int bch2_getattr(struct mnt_idmap *idmap,
+                       const struct path *path, struct kstat *stat,
                        u32 request_mask, unsigned query_flags)
 {
        struct bch_inode_info *inode = to_bch_ei(d_inode(path->dentry));
@@ -758,9 +765,9 @@ static int bch2_getattr(const struct path *path, struct kstat *stat,
        stat->gid       = inode->v.i_gid;
        stat->rdev      = inode->v.i_rdev;
        stat->size      = i_size_read(&inode->v);
-       stat->atime     = inode->v.i_atime;
-       stat->mtime     = inode->v.i_mtime;
-       stat->ctime     = inode->v.i_ctime;
+       stat->atime     = inode_get_atime(&inode->v);
+       stat->mtime     = inode_get_mtime(&inode->v);
+       stat->ctime     = inode_get_ctime(&inode->v);
        stat->blksize   = block_bytes(c);
        stat->blocks    = inode->v.i_blocks;
 
@@ -769,48 +776,54 @@ static int bch2_getattr(const struct path *path, struct kstat *stat,
                stat->btime = bch2_time_to_timespec(c, inode->ei_inode.bi_otime);
        }
 
-       if (inode->ei_inode.bi_flags & BCH_INODE_IMMUTABLE)
+       if (inode->ei_inode.bi_flags & BCH_INODE_immutable)
                stat->attributes |= STATX_ATTR_IMMUTABLE;
        stat->attributes_mask    |= STATX_ATTR_IMMUTABLE;
 
-       if (inode->ei_inode.bi_flags & BCH_INODE_APPEND)
+       if (inode->ei_inode.bi_flags & BCH_INODE_append)
                stat->attributes |= STATX_ATTR_APPEND;
        stat->attributes_mask    |= STATX_ATTR_APPEND;
 
-       if (inode->ei_inode.bi_flags & BCH_INODE_NODUMP)
+       if (inode->ei_inode.bi_flags & BCH_INODE_nodump)
                stat->attributes |= STATX_ATTR_NODUMP;
        stat->attributes_mask    |= STATX_ATTR_NODUMP;
 
        return 0;
 }
 
-static int bch2_setattr(struct dentry *dentry, struct iattr *iattr)
+static int bch2_setattr(struct mnt_idmap *idmap,
+                       struct dentry *dentry, struct iattr *iattr)
 {
        struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
+       struct bch_fs *c = inode->v.i_sb->s_fs_info;
        int ret;
 
        lockdep_assert_held(&inode->v.i_rwsem);
 
-       ret = setattr_prepare(dentry, iattr);
+       ret   = bch2_subvol_is_ro(c, inode->ei_subvol) ?:
+               setattr_prepare(idmap, dentry, iattr);
        if (ret)
                return ret;
 
        return iattr->ia_valid & ATTR_SIZE
-               ? bch2_truncate(inode, iattr)
-               : bch2_setattr_nonsize(inode, iattr);
+               ? bchfs_truncate(idmap, inode, iattr)
+               : bch2_setattr_nonsize(idmap, inode, iattr);
 }
 
-static int bch2_tmpfile(struct inode *vdir, struct dentry *dentry, umode_t mode)
+static int bch2_tmpfile(struct mnt_idmap *idmap,
+                       struct inode *vdir, struct file *file, umode_t mode)
 {
        struct bch_inode_info *inode =
-               __bch2_create(to_bch_ei(vdir), dentry, mode, 0, true);
+               __bch2_create(idmap, to_bch_ei(vdir),
+                             file->f_path.dentry, mode, 0,
+                             (subvol_inum) { 0 }, BCH_CREATE_TMPFILE);
 
        if (IS_ERR(inode))
-               return PTR_ERR(inode);
+               return bch2_err_class(PTR_ERR(inode));
 
-       d_mark_tmpfile(dentry, &inode->v);
-       d_instantiate(dentry, &inode->v);
-       return 0;
+       d_mark_tmpfile(file, &inode->v);
+       d_instantiate(file->f_path.dentry, &inode->v);
+       return finish_open_simple(file, 0);
 }
 
 static int bch2_fill_extent(struct bch_fs *c,
@@ -830,13 +843,16 @@ static int bch2_fill_extent(struct bch_fs *c,
                        int flags2 = 0;
                        u64 offset = p.ptr.offset;
 
+                       if (p.ptr.unwritten)
+                               flags2 |= FIEMAP_EXTENT_UNWRITTEN;
+
                        if (p.crc.compression_type)
                                flags2 |= FIEMAP_EXTENT_ENCODED;
                        else
                                offset += p.crc.offset;
 
-                       if ((offset & (c->opts.block_size - 1)) ||
-                           (k.k->size & (c->opts.block_size - 1)))
+                       if ((offset & (block_sectors(c) - 1)) ||
+                           (k.k->size & (block_sectors(c) - 1)))
                                flags2 |= FIEMAP_EXTENT_NOT_ALIGNED;
 
                        ret = fiemap_fill_next_extent(info,
@@ -871,13 +887,14 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
 {
        struct bch_fs *c = vinode->i_sb->s_fs_info;
        struct bch_inode_info *ei = to_bch_ei(vinode);
-       struct btree_trans trans;
-       struct btree_iter *iter;
+       struct btree_trans *trans;
+       struct btree_iter iter;
        struct bkey_s_c k;
        struct bkey_buf cur, prev;
        struct bpos end = POS(ei->v.i_ino, (start + len) >> 9);
        unsigned offset_into_extent, sectors;
        bool have_extent = false;
+       u32 snapshot;
        int ret = 0;
 
        ret = fiemap_prep(&ei->v, info, start, &len, FIEMAP_FLAG_SYNC);
@@ -887,31 +904,39 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
        if (start + len < start)
                return -EINVAL;
 
+       start >>= 9;
+
        bch2_bkey_buf_init(&cur);
        bch2_bkey_buf_init(&prev);
-       bch2_trans_init(&trans, c, 0, 0);
-
-       iter = bch2_trans_get_iter(&trans, BTREE_ID_extents,
-                                  POS(ei->v.i_ino, start >> 9), 0);
+       trans = bch2_trans_get(c);
 retry:
-       while ((k = bch2_btree_iter_peek(iter)).k &&
-              !(ret = bkey_err(k)) &&
-              bkey_cmp(iter->pos, end) < 0) {
+       bch2_trans_begin(trans);
+
+       ret = bch2_subvolume_get_snapshot(trans, ei->ei_subvol, &snapshot);
+       if (ret)
+               goto err;
+
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
+                            SPOS(ei->v.i_ino, start, snapshot), 0);
+
+       while (!(ret = btree_trans_too_many_iters(trans)) &&
+              (k = bch2_btree_iter_peek_upto(&iter, end)).k &&
+              !(ret = bkey_err(k))) {
                enum btree_id data_btree = BTREE_ID_extents;
 
                if (!bkey_extent_is_data(k.k) &&
                    k.k->type != KEY_TYPE_reservation) {
-                       bch2_btree_iter_advance(iter);
+                       bch2_btree_iter_advance(&iter);
                        continue;
                }
 
-               offset_into_extent      = iter->pos.offset -
+               offset_into_extent      = iter.pos.offset -
                        bkey_start_offset(k.k);
                sectors                 = k.k->size - offset_into_extent;
 
                bch2_bkey_buf_reassemble(&cur, c, k);
 
-               ret = bch2_read_indirect_extent(&trans, &data_btree,
+               ret = bch2_read_indirect_extent(trans, &data_btree,
                                        &offset_into_extent, &cur);
                if (ret)
                        break;
@@ -926,10 +951,11 @@ retry:
                                   offset_into_extent),
                               cur.k);
                bch2_key_resize(&cur.k->k, sectors);
-               cur.k->k.p = iter->pos;
+               cur.k->k.p = iter.pos;
                cur.k->k.p.offset += cur.k->k.size;
 
                if (have_extent) {
+                       bch2_trans_unlock(trans);
                        ret = bch2_fill_extent(c, info,
                                        bkey_i_to_s_c(prev.k), 0);
                        if (ret)
@@ -939,19 +965,22 @@ retry:
                bkey_copy(prev.k, cur.k);
                have_extent = true;
 
-               bch2_btree_iter_set_pos(iter,
-                       POS(iter->pos.inode, iter->pos.offset + sectors));
+               bch2_btree_iter_set_pos(&iter,
+                       POS(iter.pos.inode, iter.pos.offset + sectors));
        }
-
-       if (ret == -EINTR)
+       start = iter.pos.offset;
+       bch2_trans_iter_exit(trans, &iter);
+err:
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                goto retry;
 
-       if (!ret && have_extent)
+       if (!ret && have_extent) {
+               bch2_trans_unlock(trans);
                ret = bch2_fill_extent(c, info, bkey_i_to_s_c(prev.k),
                                       FIEMAP_EXTENT_LAST);
+       }
 
-       bch2_trans_iter_put(&trans, iter);
-       ret = bch2_trans_exit(&trans) ?: ret;
+       bch2_trans_put(trans);
        bch2_bkey_buf_exit(&cur, c);
        bch2_bkey_buf_exit(&prev, c);
        return ret < 0 ? ret : 0;
@@ -987,17 +1016,34 @@ static int bch2_vfs_readdir(struct file *file, struct dir_context *ctx)
        if (!dir_emit_dots(file, ctx))
                return 0;
 
-       return bch2_readdir(c, inode->v.i_ino, ctx);
+       int ret = bch2_readdir(c, inode_inum(inode), ctx);
+
+       bch_err_fn(c, ret);
+       return bch2_err_class(ret);
+}
+
+static int bch2_open(struct inode *vinode, struct file *file)
+{
+       if (file->f_flags & (O_WRONLY|O_RDWR)) {
+               struct bch_inode_info *inode = to_bch_ei(vinode);
+               struct bch_fs *c = inode->v.i_sb->s_fs_info;
+
+               int ret = bch2_subvol_is_ro(c, inode->ei_subvol);
+               if (ret)
+                       return ret;
+       }
+
+       return generic_file_open(vinode, file);
 }
 
 static const struct file_operations bch_file_operations = {
+       .open           = bch2_open,
        .llseek         = bch2_llseek,
        .read_iter      = bch2_read_iter,
        .write_iter     = bch2_write_iter,
        .mmap           = bch2_mmap,
-       .open           = generic_file_open,
        .fsync          = bch2_fsync,
-       .splice_read    = generic_file_splice_read,
+       .splice_read    = filemap_splice_read,
        .splice_write   = iter_file_splice_write,
        .fallocate      = bch2_fallocate_dispatch,
        .unlocked_ioctl = bch2_fs_file_ioctl,
@@ -1071,67 +1117,266 @@ static const struct inode_operations bch_special_inode_operations = {
 };
 
 static const struct address_space_operations bch_address_space_operations = {
-       .writepage      = bch2_writepage,
-       .readpage       = bch2_readpage,
+       .read_folio     = bch2_read_folio,
        .writepages     = bch2_writepages,
        .readahead      = bch2_readahead,
-       .set_page_dirty = __set_page_dirty_nobuffers,
+       .dirty_folio    = filemap_dirty_folio,
        .write_begin    = bch2_write_begin,
        .write_end      = bch2_write_end,
-       .invalidatepage = bch2_invalidatepage,
-       .releasepage    = bch2_releasepage,
+       .invalidate_folio = bch2_invalidate_folio,
+       .release_folio  = bch2_release_folio,
        .direct_IO      = noop_direct_IO,
 #ifdef CONFIG_MIGRATION
-       .migratepage    = bch2_migrate_page,
+       .migrate_folio  = filemap_migrate_folio,
 #endif
-       .error_remove_page = generic_error_remove_page,
+       .error_remove_folio = generic_error_remove_folio,
 };
 
-static struct inode *bch2_nfs_get_inode(struct super_block *sb,
-               u64 ino, u32 generation)
+struct bcachefs_fid {
+       u64             inum;
+       u32             subvol;
+       u32             gen;
+} __packed;
+
+struct bcachefs_fid_with_parent {
+       struct bcachefs_fid     fid;
+       struct bcachefs_fid     dir;
+} __packed;
+
+static int bcachefs_fid_valid(int fh_len, int fh_type)
 {
-       struct bch_fs *c = sb->s_fs_info;
-       struct inode *vinode;
+       switch (fh_type) {
+       case FILEID_BCACHEFS_WITHOUT_PARENT:
+               return fh_len == sizeof(struct bcachefs_fid) / sizeof(u32);
+       case FILEID_BCACHEFS_WITH_PARENT:
+               return fh_len == sizeof(struct bcachefs_fid_with_parent) / sizeof(u32);
+       default:
+               return false;
+       }
+}
+
+static struct bcachefs_fid bch2_inode_to_fid(struct bch_inode_info *inode)
+{
+       return (struct bcachefs_fid) {
+               .inum   = inode->ei_inode.bi_inum,
+               .subvol = inode->ei_subvol,
+               .gen    = inode->ei_inode.bi_generation,
+       };
+}
+
+static int bch2_encode_fh(struct inode *vinode, u32 *fh, int *len,
+                         struct inode *vdir)
+{
+       struct bch_inode_info *inode    = to_bch_ei(vinode);
+       struct bch_inode_info *dir      = to_bch_ei(vdir);
+       int min_len;
+
+       if (!S_ISDIR(inode->v.i_mode) && dir) {
+               struct bcachefs_fid_with_parent *fid = (void *) fh;
+
+               min_len = sizeof(*fid) / sizeof(u32);
+               if (*len < min_len) {
+                       *len = min_len;
+                       return FILEID_INVALID;
+               }
+
+               fid->fid = bch2_inode_to_fid(inode);
+               fid->dir = bch2_inode_to_fid(dir);
 
-       if (ino < BCACHEFS_ROOT_INO)
-               return ERR_PTR(-ESTALE);
+               *len = min_len;
+               return FILEID_BCACHEFS_WITH_PARENT;
+       } else {
+               struct bcachefs_fid *fid = (void *) fh;
+
+               min_len = sizeof(*fid) / sizeof(u32);
+               if (*len < min_len) {
+                       *len = min_len;
+                       return FILEID_INVALID;
+               }
+               *fid = bch2_inode_to_fid(inode);
 
-       vinode = bch2_vfs_inode_get(c, ino);
-       if (IS_ERR(vinode))
-               return ERR_CAST(vinode);
-       if (generation && vinode->i_generation != generation) {
-               /* we didn't find the right inode.. */
+               *len = min_len;
+               return FILEID_BCACHEFS_WITHOUT_PARENT;
+       }
+}
+
+static struct inode *bch2_nfs_get_inode(struct super_block *sb,
+                                       struct bcachefs_fid fid)
+{
+       struct bch_fs *c = sb->s_fs_info;
+       struct inode *vinode = bch2_vfs_inode_get(c, (subvol_inum) {
+                                   .subvol = fid.subvol,
+                                   .inum = fid.inum,
+       });
+       if (!IS_ERR(vinode) && vinode->i_generation != fid.gen) {
                iput(vinode);
-               return ERR_PTR(-ESTALE);
+               vinode = ERR_PTR(-ESTALE);
        }
        return vinode;
 }
 
-static struct dentry *bch2_fh_to_dentry(struct super_block *sb, struct fid *fid,
+static struct dentry *bch2_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,
-                                   bch2_nfs_get_inode);
+       struct bcachefs_fid *fid = (void *) _fid;
+
+       if (!bcachefs_fid_valid(fh_len, fh_type))
+               return NULL;
+
+       return d_obtain_alias(bch2_nfs_get_inode(sb, *fid));
 }
 
-static struct dentry *bch2_fh_to_parent(struct super_block *sb, struct fid *fid,
+static struct dentry *bch2_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,
-                                   bch2_nfs_get_inode);
+       struct bcachefs_fid_with_parent *fid = (void *) _fid;
+
+       if (!bcachefs_fid_valid(fh_len, fh_type) ||
+           fh_type != FILEID_BCACHEFS_WITH_PARENT)
+               return NULL;
+
+       return d_obtain_alias(bch2_nfs_get_inode(sb, fid->dir));
+}
+
+static struct dentry *bch2_get_parent(struct dentry *child)
+{
+       struct bch_inode_info *inode = to_bch_ei(child->d_inode);
+       struct bch_fs *c = inode->v.i_sb->s_fs_info;
+       subvol_inum parent_inum = {
+               .subvol = inode->ei_inode.bi_parent_subvol ?:
+                       inode->ei_subvol,
+               .inum = inode->ei_inode.bi_dir,
+       };
+
+       return d_obtain_alias(bch2_vfs_inode_get(c, parent_inum));
+}
+
+static int bch2_get_name(struct dentry *parent, char *name, struct dentry *child)
+{
+       struct bch_inode_info *inode    = to_bch_ei(child->d_inode);
+       struct bch_inode_info *dir      = to_bch_ei(parent->d_inode);
+       struct bch_fs *c = inode->v.i_sb->s_fs_info;
+       struct btree_trans *trans;
+       struct btree_iter iter1;
+       struct btree_iter iter2;
+       struct bkey_s_c k;
+       struct bkey_s_c_dirent d;
+       struct bch_inode_unpacked inode_u;
+       subvol_inum target;
+       u32 snapshot;
+       struct qstr dirent_name;
+       unsigned name_len = 0;
+       int ret;
+
+       if (!S_ISDIR(dir->v.i_mode))
+               return -EINVAL;
+
+       trans = bch2_trans_get(c);
+
+       bch2_trans_iter_init(trans, &iter1, BTREE_ID_dirents,
+                            POS(dir->ei_inode.bi_inum, 0), 0);
+       bch2_trans_iter_init(trans, &iter2, BTREE_ID_dirents,
+                            POS(dir->ei_inode.bi_inum, 0), 0);
+retry:
+       bch2_trans_begin(trans);
+
+       ret = bch2_subvolume_get_snapshot(trans, dir->ei_subvol, &snapshot);
+       if (ret)
+               goto err;
+
+       bch2_btree_iter_set_snapshot(&iter1, snapshot);
+       bch2_btree_iter_set_snapshot(&iter2, snapshot);
+
+       ret = bch2_inode_find_by_inum_trans(trans, inode_inum(inode), &inode_u);
+       if (ret)
+               goto err;
+
+       if (inode_u.bi_dir == dir->ei_inode.bi_inum) {
+               bch2_btree_iter_set_pos(&iter1, POS(inode_u.bi_dir, inode_u.bi_dir_offset));
+
+               k = bch2_btree_iter_peek_slot(&iter1);
+               ret = bkey_err(k);
+               if (ret)
+                       goto err;
+
+               if (k.k->type != KEY_TYPE_dirent) {
+                       ret = -BCH_ERR_ENOENT_dirent_doesnt_match_inode;
+                       goto err;
+               }
+
+               d = bkey_s_c_to_dirent(k);
+               ret = bch2_dirent_read_target(trans, inode_inum(dir), d, &target);
+               if (ret > 0)
+                       ret = -BCH_ERR_ENOENT_dirent_doesnt_match_inode;
+               if (ret)
+                       goto err;
+
+               if (target.subvol       == inode->ei_subvol &&
+                   target.inum         == inode->ei_inode.bi_inum)
+                       goto found;
+       } else {
+               /*
+                * File with multiple hardlinks and our backref is to the wrong
+                * directory - linear search:
+                */
+               for_each_btree_key_continue_norestart(iter2, 0, k, ret) {
+                       if (k.k->p.inode > dir->ei_inode.bi_inum)
+                               break;
+
+                       if (k.k->type != KEY_TYPE_dirent)
+                               continue;
+
+                       d = bkey_s_c_to_dirent(k);
+                       ret = bch2_dirent_read_target(trans, inode_inum(dir), d, &target);
+                       if (ret < 0)
+                               break;
+                       if (ret)
+                               continue;
+
+                       if (target.subvol       == inode->ei_subvol &&
+                           target.inum         == inode->ei_inode.bi_inum)
+                               goto found;
+               }
+       }
+
+       ret = -ENOENT;
+       goto err;
+found:
+       dirent_name = bch2_dirent_get_name(d);
+
+       name_len = min_t(unsigned, dirent_name.len, NAME_MAX);
+       memcpy(name, dirent_name.name, name_len);
+       name[name_len] = '\0';
+err:
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+               goto retry;
+
+       bch2_trans_iter_exit(trans, &iter1);
+       bch2_trans_iter_exit(trans, &iter2);
+       bch2_trans_put(trans);
+
+       return ret;
 }
 
 static const struct export_operations bch_export_ops = {
+       .encode_fh      = bch2_encode_fh,
        .fh_to_dentry   = bch2_fh_to_dentry,
        .fh_to_parent   = bch2_fh_to_parent,
-       //.get_parent   = bch2_get_parent,
+       .get_parent     = bch2_get_parent,
+       .get_name       = bch2_get_name,
 };
 
-static void bch2_vfs_inode_init(struct bch_fs *c,
+static void bch2_vfs_inode_init(struct btree_trans *trans, subvol_inum inum,
                                struct bch_inode_info *inode,
-                               struct bch_inode_unpacked *bi)
+                               struct bch_inode_unpacked *bi,
+                               struct bch_subvolume *subvol)
 {
-       bch2_inode_update_after_write(c, inode, bi, ~0);
+       bch2_inode_update_after_write(trans, inode, bi, ~0);
+
+       if (BCH_SUBVOLUME_SNAP(subvol))
+               set_bit(EI_INODE_SNAPSHOT, &inode->ei_flags);
+       else
+               clear_bit(EI_INODE_SNAPSHOT, &inode->ei_flags);
 
        inode->v.i_blocks       = bi->bi_sectors;
        inode->v.i_ino          = bi->bi_inum;
@@ -1140,9 +1385,9 @@ static void bch2_vfs_inode_init(struct bch_fs *c,
        inode->v.i_size         = bi->bi_size;
 
        inode->ei_flags         = 0;
-       inode->ei_journal_seq   = 0;
        inode->ei_quota_reserved = 0;
        inode->ei_qid           = bch_qid(bi);
+       inode->ei_subvol        = inum.subvol;
 
        inode->v.i_mapping->a_ops = &bch_address_space_operations;
 
@@ -1164,6 +1409,8 @@ static void bch2_vfs_inode_init(struct bch_fs *c,
                inode->v.i_op   = &bch_special_inode_operations;
                break;
        }
+
+       mapping_set_large_folios(inode->v.i_mapping);
 }
 
 static struct inode *bch2_alloc_inode(struct super_block *sb)
@@ -1176,9 +1423,9 @@ static struct inode *bch2_alloc_inode(struct super_block *sb)
 
        inode_init_once(&inode->v);
        mutex_init(&inode->ei_update_lock);
-       pagecache_lock_init(&inode->ei_pagecache_lock);
+       two_state_lock_init(&inode->ei_pagecache_lock);
+       INIT_LIST_HEAD(&inode->ei_vfs_inode_list);
        mutex_init(&inode->ei_quota_lock);
-       inode->ei_journal_seq = 0;
 
        return &inode->v;
 }
@@ -1196,15 +1443,16 @@ static void bch2_destroy_inode(struct inode *vinode)
        call_rcu(&vinode->i_rcu, bch2_i_callback);
 }
 
-static int inode_update_times_fn(struct bch_inode_info *inode,
+static int inode_update_times_fn(struct btree_trans *trans,
+                                struct bch_inode_info *inode,
                                 struct bch_inode_unpacked *bi,
                                 void *p)
 {
        struct bch_fs *c = inode->v.i_sb->s_fs_info;
 
-       bi->bi_atime    = timespec_to_bch2_time(c, inode->v.i_atime);
-       bi->bi_mtime    = timespec_to_bch2_time(c, inode->v.i_mtime);
-       bi->bi_ctime    = timespec_to_bch2_time(c, inode->v.i_ctime);
+       bi->bi_atime    = timespec_to_bch2_time(c, inode_get_atime(&inode->v));
+       bi->bi_mtime    = timespec_to_bch2_time(c, inode_get_mtime(&inode->v));
+       bi->bi_ctime    = timespec_to_bch2_time(c, inode_get_ctime(&inode->v));
 
        return 0;
 }
@@ -1221,7 +1469,7 @@ static int bch2_vfs_write_inode(struct inode *vinode,
                               ATTR_ATIME|ATTR_MTIME|ATTR_CTIME);
        mutex_unlock(&inode->ei_update_lock);
 
-       return ret;
+       return bch2_err_class(ret);
 }
 
 static void bch2_evict_inode(struct inode *vinode)
@@ -1240,8 +1488,76 @@ static void bch2_evict_inode(struct inode *vinode)
                                KEY_TYPE_QUOTA_WARN);
                bch2_quota_acct(c, inode->ei_qid, Q_INO, -1,
                                KEY_TYPE_QUOTA_WARN);
-               bch2_inode_rm(c, inode->v.i_ino, true);
+               bch2_inode_rm(c, inode_inum(inode));
+       }
+
+       mutex_lock(&c->vfs_inodes_lock);
+       list_del_init(&inode->ei_vfs_inode_list);
+       mutex_unlock(&c->vfs_inodes_lock);
+}
+
+void bch2_evict_subvolume_inodes(struct bch_fs *c, snapshot_id_list *s)
+{
+       struct bch_inode_info *inode;
+       DARRAY(struct bch_inode_info *) grabbed;
+       bool clean_pass = false, this_pass_clean;
+
+       /*
+        * Initially, we scan for inodes without I_DONTCACHE, then mark them to
+        * be pruned with d_mark_dontcache().
+        *
+        * Once we've had a clean pass where we didn't find any inodes without
+        * I_DONTCACHE, we wait for them to be freed:
+        */
+
+       darray_init(&grabbed);
+       darray_make_room(&grabbed, 1024);
+again:
+       cond_resched();
+       this_pass_clean = true;
+
+       mutex_lock(&c->vfs_inodes_lock);
+       list_for_each_entry(inode, &c->vfs_inodes_list, ei_vfs_inode_list) {
+               if (!snapshot_list_has_id(s, inode->ei_subvol))
+                       continue;
+
+               if (!(inode->v.i_state & I_DONTCACHE) &&
+                   !(inode->v.i_state & I_FREEING) &&
+                   igrab(&inode->v)) {
+                       this_pass_clean = false;
+
+                       if (darray_push_gfp(&grabbed, inode, GFP_ATOMIC|__GFP_NOWARN)) {
+                               iput(&inode->v);
+                               break;
+                       }
+               } else if (clean_pass && this_pass_clean) {
+                       wait_queue_head_t *wq = bit_waitqueue(&inode->v.i_state, __I_NEW);
+                       DEFINE_WAIT_BIT(wait, &inode->v.i_state, __I_NEW);
+
+                       prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+                       mutex_unlock(&c->vfs_inodes_lock);
+
+                       schedule();
+                       finish_wait(wq, &wait.wq_entry);
+                       goto again;
+               }
        }
+       mutex_unlock(&c->vfs_inodes_lock);
+
+       darray_for_each(grabbed, i) {
+               inode = *i;
+               d_mark_dontcache(&inode->v);
+               d_prune_aliases(&inode->v);
+               iput(&inode->v);
+       }
+       grabbed.nr = 0;
+
+       if (!clean_pass || !this_pass_clean) {
+               clean_pass = this_pass_clean;
+               goto again;
+       }
+
+       darray_exit(&grabbed);
 }
 
 static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
@@ -1260,8 +1576,8 @@ static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
        buf->f_type     = BCACHEFS_STATFS_MAGIC;
        buf->f_bsize    = sb->s_blocksize;
        buf->f_blocks   = usage.capacity >> shift;
-       buf->f_bfree    = (usage.capacity - usage.used) >> shift;
-       buf->f_bavail   = buf->f_bfree;
+       buf->f_bfree    = usage.free >> shift;
+       buf->f_bavail   = avail_factor(usage.free) >> shift;
 
        buf->f_files    = usage.nr_inodes + avail_inodes;
        buf->f_ffree    = avail_inodes;
@@ -1278,6 +1594,7 @@ static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
 static int bch2_sync_fs(struct super_block *sb, int wait)
 {
        struct bch_fs *c = sb->s_fs_info;
+       int ret;
 
        if (c->opts.journal_flush_disabled)
                return 0;
@@ -1287,7 +1604,8 @@ static int bch2_sync_fs(struct super_block *sb, int wait)
                return 0;
        }
 
-       return bch2_journal_flush(&c->journal);
+       ret = bch2_journal_flush(&c->journal);
+       return bch2_err_class(ret);
 }
 
 static struct bch_fs *bch2_path_to_fs(const char *path)
@@ -1306,44 +1624,17 @@ static struct bch_fs *bch2_path_to_fs(const char *path)
        return c ?: ERR_PTR(-ENOENT);
 }
 
-static char **split_devs(const char *_dev_name, unsigned *nr)
-{
-       char *dev_name = NULL, **devs = NULL, *s;
-       size_t i, nr_devs = 0;
-
-       dev_name = kstrdup(_dev_name, GFP_KERNEL);
-       if (!dev_name)
-               return NULL;
-
-       for (s = dev_name; s; s = strchr(s + 1, ':'))
-               nr_devs++;
-
-       devs = kcalloc(nr_devs + 1, sizeof(const char *), GFP_KERNEL);
-       if (!devs) {
-               kfree(dev_name);
-               return NULL;
-       }
-
-       for (i = 0, s = dev_name;
-            s;
-            (s = strchr(s, ':')) && (*s++ = '\0'))
-               devs[i++] = s;
-
-       *nr = nr_devs;
-       return devs;
-}
-
 static int bch2_remount(struct super_block *sb, int *flags, char *data)
 {
        struct bch_fs *c = sb->s_fs_info;
        struct bch_opts opts = bch2_opts_empty();
        int ret;
 
-       opt_set(opts, read_only, (*flags & SB_RDONLY) != 0);
-
        ret = bch2_parse_mount_opts(c, &opts, data);
        if (ret)
-               return ret;
+               goto err;
+
+       opt_set(opts, read_only, (*flags & SB_RDONLY) != 0);
 
        if (opts.read_only != c->opts.read_only) {
                down_write(&c->state_lock);
@@ -1357,7 +1648,8 @@ static int bch2_remount(struct super_block *sb, int *flags, char *data)
                        if (ret) {
                                bch_err(c, "error going rw: %i", ret);
                                up_write(&c->state_lock);
-                               return -EINVAL;
+                               ret = -EINVAL;
+                               goto err;
                        }
 
                        sb->s_flags &= ~SB_RDONLY;
@@ -1368,25 +1660,22 @@ static int bch2_remount(struct super_block *sb, int *flags, char *data)
                up_write(&c->state_lock);
        }
 
-       if (opts.errors >= 0)
+       if (opt_defined(opts, errors))
                c->opts.errors = opts.errors;
-
-       return ret;
+err:
+       return bch2_err_class(ret);
 }
 
 static int bch2_show_devname(struct seq_file *seq, struct dentry *root)
 {
        struct bch_fs *c = root->d_sb->s_fs_info;
-       struct bch_dev *ca;
-       unsigned i;
        bool first = true;
 
-       for_each_online_member(ca, c, i) {
+       for_each_online_member(c, ca) {
                if (!first)
                        seq_putc(seq, ':');
                first = false;
-               seq_puts(seq, "/dev/");
-               seq_puts(seq, ca->name);
+               seq_puts(seq, ca->disk_sb.sb_name);
        }
 
        return 0;
@@ -1396,25 +1685,30 @@ static int bch2_show_options(struct seq_file *seq, struct dentry *root)
 {
        struct bch_fs *c = root->d_sb->s_fs_info;
        enum bch_opt_id i;
-       char buf[512];
+       struct printbuf buf = PRINTBUF;
+       int ret = 0;
 
        for (i = 0; i < bch2_opts_nr; i++) {
                const struct bch_option *opt = &bch2_opt_table[i];
                u64 v = bch2_opt_get_by_id(&c->opts, i);
 
-               if (!(opt->mode & OPT_MOUNT))
+               if (!(opt->flags & OPT_MOUNT))
                        continue;
 
                if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
                        continue;
 
-               bch2_opt_to_text(&PBUF(buf), c, opt, v,
+               printbuf_reset(&buf);
+               bch2_opt_to_text(&buf, c, c->disk_sb.sb, opt, v,
                                 OPT_SHOW_MOUNT_STYLE);
                seq_putc(seq, ',');
-               seq_puts(seq, buf);
+               seq_puts(seq, buf.buf);
        }
 
-       return 0;
+       if (buf.allocation_failure)
+               ret = -ENOMEM;
+       printbuf_exit(&buf);
+       return ret;
 }
 
 static void bch2_put_super(struct super_block *sb)
@@ -1424,6 +1718,38 @@ static void bch2_put_super(struct super_block *sb)
        __bch2_fs_stop(c);
 }
 
+/*
+ * bcachefs doesn't currently integrate intwrite freeze protection but the
+ * internal write references serve the same purpose. Therefore reuse the
+ * read-only transition code to perform the quiesce. The caveat is that we don't
+ * currently have the ability to block tasks that want a write reference while
+ * the superblock is frozen. This is fine for now, but we should either add
+ * blocking support or find a way to integrate sb_start_intwrite() and friends.
+ */
+static int bch2_freeze(struct super_block *sb)
+{
+       struct bch_fs *c = sb->s_fs_info;
+
+       down_write(&c->state_lock);
+       bch2_fs_read_only(c);
+       up_write(&c->state_lock);
+       return 0;
+}
+
+static int bch2_unfreeze(struct super_block *sb)
+{
+       struct bch_fs *c = sb->s_fs_info;
+       int ret;
+
+       if (test_bit(BCH_FS_emergency_ro, &c->flags))
+               return 0;
+
+       down_write(&c->state_lock);
+       ret = bch2_fs_read_write(c);
+       up_write(&c->state_lock);
+       return ret;
+}
+
 static const struct super_operations bch_super_operations = {
        .alloc_inode    = bch2_alloc_inode,
        .destroy_inode  = bch2_destroy_inode,
@@ -1435,10 +1761,8 @@ static const struct super_operations bch_super_operations = {
        .show_options   = bch2_show_options,
        .remount_fs     = bch2_remount,
        .put_super      = bch2_put_super,
-#if 0
        .freeze_fs      = bch2_freeze,
        .unfreeze_fs    = bch2_unfreeze,
-#endif
 };
 
 static int bch2_set_super(struct super_block *s, void *data)
@@ -1452,17 +1776,18 @@ static int bch2_noset_super(struct super_block *s, void *data)
        return -EBUSY;
 }
 
+typedef DARRAY(struct bch_fs *) darray_fs;
+
 static int bch2_test_super(struct super_block *s, void *data)
 {
        struct bch_fs *c = s->s_fs_info;
-       struct bch_fs **devs = data;
-       unsigned i;
+       darray_fs *d = data;
 
        if (!c)
                return false;
 
-       for (i = 0; devs[i]; i++)
-               if (c != devs[i])
+       darray_for_each(*d, i)
+               if (c != *i)
                        return false;
        return true;
 }
@@ -1471,13 +1796,9 @@ static struct dentry *bch2_mount(struct file_system_type *fs_type,
                                 int flags, const char *dev_name, void *data)
 {
        struct bch_fs *c;
-       struct bch_dev *ca;
        struct super_block *sb;
        struct inode *vinode;
        struct bch_opts opts = bch2_opts_empty();
-       char **devs;
-       struct bch_fs **devs_to_fs = NULL;
-       unsigned i, nr_devs;
        int ret;
 
        opt_set(opts, read_only, (flags & SB_RDONLY) != 0);
@@ -1486,25 +1807,28 @@ static struct dentry *bch2_mount(struct file_system_type *fs_type,
        if (ret)
                return ERR_PTR(ret);
 
-       devs = split_devs(dev_name, &nr_devs);
-       if (!devs)
-               return ERR_PTR(-ENOMEM);
+       if (!dev_name || strlen(dev_name) == 0)
+               return ERR_PTR(-EINVAL);
 
-       devs_to_fs = kcalloc(nr_devs + 1, sizeof(void *), GFP_KERNEL);
-       if (!devs_to_fs) {
-               sb = ERR_PTR(-ENOMEM);
-               goto got_sb;
-       }
+       darray_str devs;
+       ret = bch2_split_devs(dev_name, &devs);
+       if (ret)
+               return ERR_PTR(ret);
 
-       for (i = 0; i < nr_devs; i++)
-               devs_to_fs[i] = bch2_path_to_fs(devs[i]);
+       darray_fs devs_to_fs = {};
+       darray_for_each(devs, i) {
+               ret = darray_push(&devs_to_fs, bch2_path_to_fs(*i));
+               if (ret) {
+                       sb = ERR_PTR(ret);
+                       goto got_sb;
+               }
+       }
 
-       sb = sget(fs_type, bch2_test_super, bch2_noset_super,
-                 flags|SB_NOSEC, devs_to_fs);
+       sb = sget(fs_type, bch2_test_super, bch2_noset_super, flags|SB_NOSEC, &devs_to_fs);
        if (!IS_ERR(sb))
                goto got_sb;
 
-       c = bch2_fs_open(devs, nr_devs, opts);
+       c = bch2_fs_open(devs.data, devs.nr, opts);
        if (IS_ERR(c)) {
                sb = ERR_CAST(c);
                goto got_sb;
@@ -1524,12 +1848,14 @@ static struct dentry *bch2_mount(struct file_system_type *fs_type,
        if (IS_ERR(sb))
                bch2_fs_stop(c);
 got_sb:
-       kfree(devs_to_fs);
-       kfree(devs[0]);
-       kfree(devs);
+       darray_exit(&devs_to_fs);
+       bch2_darray_str_exit(&devs);
 
-       if (IS_ERR(sb))
-               return ERR_CAST(sb);
+       if (IS_ERR(sb)) {
+               ret = PTR_ERR(sb);
+               ret = bch2_err_class(ret);
+               return ERR_PTR(ret);
+       }
 
        c = sb->s_fs_info;
 
@@ -1556,7 +1882,7 @@ got_sb:
        sb->s_time_min          = div_s64(S64_MIN, c->sb.time_units_per_sec) + 1;
        sb->s_time_max          = div_s64(S64_MAX, c->sb.time_units_per_sec);
        c->vfs_sb               = sb;
-       strlcpy(sb->s_id, c->name, sizeof(sb->s_id));
+       strscpy(sb->s_id, c->name, sizeof(sb->s_id));
 
        ret = super_setup_bdi(sb);
        if (ret)
@@ -1564,7 +1890,7 @@ got_sb:
 
        sb->s_bdi->ra_pages             = VM_READAHEAD_PAGES;
 
-       for_each_online_member(ca, c, i) {
+       for_each_online_member(c, ca) {
                struct block_device *bdev = ca->disk_sb.bdev;
 
                /* XXX: create an anonymous device for multi device filesystems */
@@ -1574,18 +1900,20 @@ got_sb:
                break;
        }
 
+       c->dev = sb->s_dev;
+
 #ifdef CONFIG_BCACHEFS_POSIX_ACL
        if (c->opts.acl)
                sb->s_flags     |= SB_POSIXACL;
 #endif
 
-       vinode = bch2_vfs_inode_get(c, BCACHEFS_ROOT_INO);
-       if (IS_ERR(vinode)) {
-               bch_err(c, "error mounting: error getting root inode %i",
-                       (int) PTR_ERR(vinode));
-               ret = PTR_ERR(vinode);
+       sb->s_shrink->seeks = 0;
+
+       vinode = bch2_vfs_inode_get(c, BCACHEFS_ROOT_SUBVOL_INUM);
+       ret = PTR_ERR_OR_ZERO(vinode);
+       bch_err_msg(c, ret, "mounting: error getting root inode");
+       if (ret)
                goto err_put_super;
-       }
 
        sb->s_root = d_make_root(vinode);
        if (!sb->s_root) {
@@ -1600,7 +1928,7 @@ out:
 
 err_put_super:
        deactivate_locked_super(sb);
-       return ERR_PTR(ret);
+       return ERR_PTR(bch2_err_class(ret));
 }
 
 static void bch2_kill_sb(struct super_block *sb)
@@ -1624,15 +1952,14 @@ MODULE_ALIAS_FS("bcachefs");
 void bch2_vfs_exit(void)
 {
        unregister_filesystem(&bcache_fs_type);
-       if (bch2_inode_cache)
-               kmem_cache_destroy(bch2_inode_cache);
+       kmem_cache_destroy(bch2_inode_cache);
 }
 
 int __init bch2_vfs_init(void)
 {
        int ret = -ENOMEM;
 
-       bch2_inode_cache = KMEM_CACHE(bch_inode_info, 0);
+       bch2_inode_cache = KMEM_CACHE(bch_inode_info, SLAB_RECLAIM_ACCOUNT);
        if (!bch2_inode_cache)
                goto err;