bcachefs: bch2_inode_insert()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index be0c059d70f03d7f1ab94100a43babdbca630ad9..bcc1436c1720680632193d35c912d45271b8747e 100644 (file)
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -176,45 +176,88 @@ 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)
+static struct bch_inode_info *bch2_inode_insert(struct bch_fs *c, struct bch_inode_info *inode)
 {
-       struct bch_inode_unpacked inode_u;
-       struct bch_inode_info *inode;
-       struct btree_trans *trans;
-       struct bch_subvolume subvol;
-       int ret;
+       subvol_inum inum = inode_inum(inode);
+       struct bch_inode_info *old = to_bch_ei(inode_insert5(&inode->v,
+                                     bch2_inode_hash(inum),
+                                     bch2_iget5_test,
+                                     bch2_iget5_set,
+                                     &inum));
+       BUG_ON(!old);
 
-       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;
+       if (unlikely(old != inode)) {
+               discard_new_inode(&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...
+                */
+               unlock_new_inode(&inode->v);
+       }
 
-       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));
+       return inode;
+}
 
-       if (!ret)
-               bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
-       bch2_trans_put(trans);
+#define memalloc_flags_do(_flags, _do)                                         \
+({                                                                             \
+       unsigned _saved_flags = memalloc_flags_save(_flags);                    \
+       typeof(_do) _ret = _do;                                                 \
+       memalloc_noreclaim_restore(_saved_flags);                               \
+       _ret;                                                                   \
+})
 
-       if (ret) {
-               iget_failed(&inode->v);
-               return ERR_PTR(bch2_err_class(ret));
+/*
+ * Allocate a new inode, dropping/retaking btree locks if necessary:
+ */
+static struct bch_inode_info *bch2_new_inode(struct btree_trans *trans)
+{
+       struct bch_fs *c = trans->c;
+
+       struct bch_inode_info *inode =
+               memalloc_flags_do(PF_MEMALLOC_NORECLAIM|PF_MEMALLOC_NOWARN,
+                                 to_bch_ei(new_inode(c->vfs_sb)));
+
+       if (unlikely(!inode)) {
+               int ret = drop_locks_do(trans, (inode = to_bch_ei(new_inode(c->vfs_sb))) ? 0 : -ENOMEM);
+               if (ret && inode)
+                       discard_new_inode(&inode->v);
+               if (ret)
+                       return ERR_PTR(ret);
        }
 
-       mutex_lock(&c->vfs_inodes_lock);
-       list_add(&inode->ei_vfs_inode_list, &c->vfs_inodes_list);
-       mutex_unlock(&c->vfs_inodes_lock);
+       return inode;
+}
 
-       unlock_new_inode(&inode->v);
+struct inode *bch2_vfs_inode_get(struct bch_fs *c, subvol_inum inum)
+{
+       struct bch_inode_info *inode =
+               to_bch_ei(ilookup5_nowait(c->vfs_sb,
+                                         bch2_inode_hash(inum),
+                                         bch2_iget5_test,
+                                         &inum));
+       if (inode)
+               return &inode->v;
 
-       return &inode->v;
+       struct btree_trans *trans = bch2_trans_get(c);
+
+       struct bch_inode_unpacked inode_u;
+       struct bch_subvolume subvol;
+       int ret = lockrestart_do(trans,
+               bch2_subvolume_get(trans, inum.subvol, true, 0, &subvol) ?:
+               bch2_inode_find_by_inum_trans(trans, inum, &inode_u)) ?:
+               PTR_ERR_OR_ZERO(inode = bch2_new_inode(trans));
+       if (!ret) {
+               bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
+               inode = bch2_inode_insert(c, inode);
+       }
+       bch2_trans_put(trans);
+
+       return ret ? ERR_PTR(ret) : &inode->v;
 }
 
 struct bch_inode_info *
@@ -226,7 +269,7 @@ __bch2_create(struct mnt_idmap *idmap,
        struct bch_fs *c = dir->v.i_sb->s_fs_info;
        struct btree_trans *trans;
        struct bch_inode_unpacked dir_u;
-       struct bch_inode_info *inode, *old;
+       struct bch_inode_info *inode;
        struct bch_inode_unpacked inode_u;
        struct posix_acl *default_acl = NULL, *acl = NULL;
        subvol_inum inum;
@@ -293,7 +336,6 @@ err_before_quota:
                mutex_unlock(&dir->ei_update_lock);
        }
 
-       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);
@@ -304,36 +346,7 @@ err_before_quota:
         * bch2_trans_exit() and dropping locks, else we could race with another
         * thread pulling the inode in and modifying it:
         */
-
-       inode->v.i_state |= I_CREATING;
-
-       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)) {
-               /*
-                * We raced, another process pulled the new inode into cache
-                * before us:
-                */
-               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...
-                */
-               unlock_new_inode(&inode->v);
-       }
-
+       inode = bch2_inode_insert(c, inode);
        bch2_trans_put(trans);
 err:
        posix_acl_release(default_acl);
@@ -1372,6 +1385,7 @@ static void bch2_vfs_inode_init(struct btree_trans *trans, subvol_inum inum,
                                struct bch_inode_unpacked *bi,
                                struct bch_subvolume *subvol)
 {
+       bch2_iget5_set(&inode->v, &inum);
        bch2_inode_update_after_write(trans, inode, bi, ~0);
 
        if (BCH_SUBVOLUME_SNAP(subvol))