Hi, I love your patch! Perhaps something to improve: [auto build test WARNING on hch-configfs/for-next] [cannot apply to linus/master v5.19-rc1 next-20220607] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/intel-lab-lkp/linux/commits/gregkh-linuxfoundation-org/FAILED-patch-PATCH-exportfs-support-idmapped-mounts-failed-to-apply-to-5-4-stable-tree/20220606-203330 base: git://git.infradead.org/users/hch/configfs.git for-next config: x86_64-rhel-8.3 (https://download.01.org/0day-ci/archive/20220607/202206072252.SYRt38ih-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-1) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/cda5e21742a0ec193c2dfd7e445a2024f9685eb9 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review gregkh-linuxfoundation-org/FAILED-patch-PATCH-exportfs-support-idmapped-mounts-failed-to-apply-to-5-4-stable-tree/20220606-203330 git checkout cda5e21742a0ec193c2dfd7e445a2024f9685eb9 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/exportfs/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): fs/exportfs/expfs.c: In function 'reconnect_one': fs/exportfs/expfs.c:148:15: error: implicit declaration of function 'lookup_one_unlocked'; did you mean 'lookup_one_len_unlocked'? [-Werror=implicit-function-declaration] 148 | tmp = lookup_one_unlocked(mnt_user_ns(mnt), nbuf, parent, strlen(nbuf)); | ^~~~~~~~~~~~~~~~~~~ | lookup_one_len_unlocked >> fs/exportfs/expfs.c:148:13: warning: assignment to 'struct dentry *' from 'int' makes pointer from integer without a cast [-Wint-conversion] 148 | tmp = lookup_one_unlocked(mnt_user_ns(mnt), nbuf, parent, strlen(nbuf)); | ^ cc1: some warnings being treated as errors vim +148 fs/exportfs/expfs.c 108 109 /* 110 * Reconnect a directory dentry with its parent. 111 * 112 * This can return a dentry, or NULL, or an error. 113 * 114 * In the first case the returned dentry is the parent of the given 115 * dentry, and may itself need to be reconnected to its parent. 116 * 117 * In the NULL case, a concurrent VFS operation has either renamed or 118 * removed this directory. The concurrent operation has reconnected our 119 * dentry, so we no longer need to. 120 */ 121 static struct dentry *reconnect_one(struct vfsmount *mnt, 122 struct dentry *dentry, char *nbuf) 123 { 124 struct dentry *parent; 125 struct dentry *tmp; 126 int err; 127 128 parent = ERR_PTR(-EACCES); 129 inode_lock(dentry->d_inode); 130 if (mnt->mnt_sb->s_export_op->get_parent) 131 parent = mnt->mnt_sb->s_export_op->get_parent(dentry); 132 inode_unlock(dentry->d_inode); 133 134 if (IS_ERR(parent)) { 135 dprintk("%s: get_parent of %ld failed, err %d\n", 136 __func__, dentry->d_inode->i_ino, PTR_ERR(parent)); 137 return parent; 138 } 139 140 dprintk("%s: find name of %lu in %lu\n", __func__, 141 dentry->d_inode->i_ino, parent->d_inode->i_ino); 142 err = exportfs_get_name(mnt, parent, nbuf, dentry); 143 if (err == -ENOENT) 144 goto out_reconnected; 145 if (err) 146 goto out_err; 147 dprintk("%s: found name: %s\n", __func__, nbuf); > 148 tmp = lookup_one_unlocked(mnt_user_ns(mnt), nbuf, parent, strlen(nbuf)); 149 if (IS_ERR(tmp)) { 150 dprintk("%s: lookup failed: %d\n", __func__, PTR_ERR(tmp)); 151 err = PTR_ERR(tmp); 152 goto out_err; 153 } 154 if (tmp != dentry) { 155 /* 156 * Somebody has renamed it since exportfs_get_name(); 157 * great, since it could've only been renamed if it 158 * got looked up and thus connected, and it would 159 * remain connected afterwards. We are done. 160 */ 161 dput(tmp); 162 goto out_reconnected; 163 } 164 dput(tmp); 165 if (IS_ROOT(dentry)) { 166 err = -ESTALE; 167 goto out_err; 168 } 169 return parent; 170 171 out_err: 172 dput(parent); 173 return ERR_PTR(err); 174 out_reconnected: 175 dput(parent); 176 /* 177 * Someone must have renamed our entry into another parent, in 178 * which case it has been reconnected by the rename. 179 * 180 * Or someone removed it entirely, in which case filehandle 181 * lookup will succeed but the directory is now IS_DEAD and 182 * subsequent operations on it will fail. 183 * 184 * Alternatively, maybe there was no race at all, and the 185 * filesystem is just corrupt and gave us a parent that doesn't 186 * actually contain any entry pointing to this inode. So, 187 * double check that this worked and return -ESTALE if not: 188 */ 189 if (!dentry_connected(dentry)) 190 return ERR_PTR(-ESTALE); 191 return NULL; 192 } 193 -- 0-DAY CI Kernel Test Service https://01.org/lkp