Messages in this thread | | | Date | Sat, 1 Jul 2023 07:36:20 +0800 | Subject | Re: [f2fs-dev] [PATCH v2] f2fs: fix deadlock in i_xattr_sem and inode page lock and fix the original issue | From | Chao Yu <> |
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On 2023/7/1 5:59, Jaegeuk Kim wrote: > On 06/28, Jaegeuk Kim wrote: >> On 06/28, Chao Yu wrote: >>> On 2023/6/28 16:08, Jaegeuk Kim wrote: >>>> 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 >>> >>> Back to the race condition, my question is why we can chmod on inode before >>> it has been created? >> >> This is touching the directory. > > Chao, > > Do you have other concern? Otherwise, I'll include this into the next pull > request.
Jaegeuk,
Sorry for late reply, I was misled by "dir->inode_page" and "inode" words in commit message, it should be "dir->inode_page" and "dir_inode".
Anyway, the patch looks good to me.
Reviewed-by: Chao Yu <chao@kernel.org>
Thanks,
> > Thanks, > >> >>> >>> Thanks, >>> >>>> >>>> Fixes: 27161f13e3c3 "f2fs: avoid race in between read xattr & write xattr" >>>> Cc: <stable@vger.kernel.org> >>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> >>>> --- >>>> 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 887e55988450..d635c58cf5a3 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 213805d3592c..476b186b90a6 100644 >>>> --- a/fs/f2fs/xattr.c >>>> +++ b/fs/f2fs/xattr.c >>>> @@ -528,10 +528,12 @@ 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; >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
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