The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 5eda1ad1aaffdfebdecf7a164e586060a210f74f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023072038-aviation-crepe-3bf1@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

5eda1ad1aaff ("f2fs: fix deadlock in i_xattr_sem and inode page lock") e4544b63a7ee ("f2fs: move f2fs to use reader-unfair rwsems") 3e0203893e0d ("f2fs: support fault injection to f2fs_trylock_op()") a9419b63bf41 ("f2fs: do not bother checkpoint by f2fs_get_node_info") 0df035c7208c ("f2fs: avoid down_write on nat_tree_lock during checkpoint") a1e09b03e6f5 ("f2fs: use iomap for direct I/O") ccf7cf92373d ("f2fs: fix the f2fs_file_write_iter tracepoint") d4dd19ec1ea0 ("f2fs: do not expose unwritten blocks to user by DIO") b31bf0f96e71 ("f2fs: reduce indentation in f2fs_file_write_iter()") 3d697a4a6b7d ("f2fs: rework write preallocations") 5664896ba29e ("Merge tag 'f2fs-for-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5eda1ad1aaffdfebdecf7a164e586060a210f74f Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim jaegeuk@kernel.org 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

Cc: stable@vger.kernel.org Fixes: 27161f13e3c3 "f2fs: avoid race in between read xattr & write xattr" Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org

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;