From 82d8a4f642421ece594542e1fabc689dcb094b1a Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 28 Jun 2023 01:00:56 -0700 Subject: [PATCH] f2fs: fix deadlock in i_xattr_sem and inode page lock Thread #1: [122554.641906][ T92] f2fs_getxattr+0xd4/0x5fc -> waiting for f2fs_down_read(&F2FS_I(inode)->i_xattr_sem); [122554.641927][ T92] __f2fs_get_acl+0x50/0x284 [122554.641948][ T92] f2fs_init_acl+0x84/0x54c [122554.641969][ T92] f2fs_init_inode_metadata+0x460/0x5f0 [122554.641990][ T92] f2fs_add_inline_entry+0x11c/0x350 -> Locked dir->inode_page by f2fs_get_node_page() [122554.642009][ T92] f2fs_do_add_link+0x100/0x1e4 [122554.642025][ T92] f2fs_create+0xf4/0x22c [122554.642047][ T92] vfs_create+0x130/0x1f4 Thread #2: [123996.386358][ T92] __get_node_page+0x8c/0x504 -> waiting for dir->inode_page lock [123996.386383][ T92] read_all_xattrs+0x11c/0x1f4 [123996.386405][ T92] __f2fs_setxattr+0xcc/0x528 [123996.386424][ T92] f2fs_setxattr+0x158/0x1f4 -> f2fs_down_write(&F2FS_I(inode)->i_xattr_sem); [123996.386443][ T92] __f2fs_set_acl+0x328/0x430 [123996.386618][ T92] f2fs_set_acl+0x38/0x50 [123996.386642][ T92] posix_acl_chmod+0xc8/0x1c8 [123996.386669][ T92] f2fs_setattr+0x5e0/0x6bc [123996.386689][ T92] notify_change+0x4d8/0x580 [123996.386717][ T92] chmod_common+0xd8/0x184 [123996.386748][ T92] do_fchmodat+0x60/0x124 [123996.386766][ T92] __arm64_sys_fchmodat+0x28/0x3c Fixes: 27161f13e3c3 "f2fs: avoid race in between read xattr & write xattr" Cc: Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 9 ++++++++- fs/f2fs/xattr.c | 6 ++++-- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 30cb141abc646..315cd77fa7f12 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -775,8 +775,15 @@ int f2fs_add_dentry(struct inode *dir, const struct f2fs_filename *fname, { int err = -EAGAIN; - if (f2fs_has_inline_dentry(dir)) + if (f2fs_has_inline_dentry(dir)) { + /* + * Should get i_xattr_sem to keep the lock order: + * i_xattr_sem -> inode_page lock used by f2fs_setxattr. + */ + f2fs_down_read(&F2FS_I(dir)->i_xattr_sem); err = f2fs_add_inline_entry(dir, fname, inode, ino, mode); + f2fs_up_read(&F2FS_I(dir)->i_xattr_sem); + } if (err == -EAGAIN) err = f2fs_add_regular_entry(dir, fname, inode, ino, mode); diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index dc2e8637189e2..db3b641f2158c 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -527,10 +527,12 @@ int f2fs_getxattr(struct inode *inode, int index, const char *name, if (len > F2FS_NAME_LEN) return -ERANGE; - f2fs_down_read(&F2FS_I(inode)->i_xattr_sem); + if (!ipage) + f2fs_down_read(&F2FS_I(inode)->i_xattr_sem); error = lookup_all_xattrs(inode, ipage, index, len, name, &entry, &base_addr, &base_size, &is_inline); - f2fs_up_read(&F2FS_I(inode)->i_xattr_sem); + if (!ipage) + f2fs_up_read(&F2FS_I(inode)->i_xattr_sem); if (error) return error;