The __f2fs_add_link is covered by cp_rwsem all the time.
This calls init_inode_metadata, which conducts some acl operations including
memory allocation with GFP_KERNEL previously.
But, under memory pressure, f2fs_write_data_page can be called, which also
grabs cp_rwsem too.
In this case, this incurs a deadlock pointed by Chao.
Thread #1 Thread #2
down_read
down_write
down_read
-> here down_read should wait forever.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Use clear_inode_flag to replace the redundant cond_clear_inode_flag.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previously, init_inode_metadata does not hold any parent directory's inode
page. So, f2fs_init_acl can grab its parent inode page without any problem.
But, when we use inline_dentry, that page is grabbed during f2fs_add_link,
so that we can fall into deadlock condition like below.
INFO: task mknod:11006 blocked for more than 120 seconds.
Tainted: G OE 3.17.0-rc1+ #13
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mknod D ffff88003fc94580 0 11006 11004 0x00000000
ffff880007717b10 0000000000000002 ffff88003c323220 ffff880007717fd8
0000000000014580 0000000000014580 ffff88003daecb30 ffff88003c323220
ffff88003fc94e80 ffff88003ffbb4e8 ffff880007717ba0 0000000000000002
Call Trace:
[<ffffffff8173dc40>] ? bit_wait+0x50/0x50
[<ffffffff8173d4cd>] io_schedule+0x9d/0x130
[<ffffffff8173dc6c>] bit_wait_io+0x2c/0x50
[<ffffffff8173da3b>] __wait_on_bit_lock+0x4b/0xb0
[<ffffffff811640a7>] __lock_page+0x67/0x70
[<ffffffff810acf50>] ? autoremove_wake_function+0x40/0x40
[<ffffffff811652cc>] pagecache_get_page+0x14c/0x1e0
[<ffffffffa029afa9>] get_node_page+0x59/0x130 [f2fs]
[<ffffffffa02a63ad>] read_all_xattrs+0x24d/0x430 [f2fs]
[<ffffffffa02a6ca2>] f2fs_getxattr+0x52/0xe0 [f2fs]
[<ffffffffa02a7481>] f2fs_get_acl+0x41/0x2d0 [f2fs]
[<ffffffff8122d847>] get_acl+0x47/0x70
[<ffffffff8122db5a>] posix_acl_create+0x5a/0x150
[<ffffffffa02a7759>] f2fs_init_acl+0x29/0xcb [f2fs]
[<ffffffffa0286a8d>] init_inode_metadata+0x5d/0x340 [f2fs]
[<ffffffffa029253a>] f2fs_add_inline_entry+0x12a/0x2e0 [f2fs]
[<ffffffffa0286ea5>] __f2fs_add_link+0x45/0x4a0 [f2fs]
[<ffffffffa028b5b6>] ? f2fs_new_inode+0x146/0x220 [f2fs]
[<ffffffffa028b816>] f2fs_mknod+0x86/0xf0 [f2fs]
[<ffffffff811e3ec1>] vfs_mknod+0xe1/0x160
[<ffffffff811e4b26>] SyS_mknod+0x1f6/0x200
[<ffffffff81741d7f>] tracesys+0xe1/0xe6
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
kernel side(xx_init_acl), the acl is get/cloned from the parent dir's,
which is credible. So remove the redundant validation check of acl
here.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch passes the "flags" field to the low level setxattr functions
to use XATTR_REPLACE in the following patches.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Before setting the acl, call posix_acl_valid() to check if it is
valid or not.
Signed-off-by: zhangzhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs has some weird mode bit handling, so still using the old
chmod code for now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Rename the current posix_acl_created to __posix_acl_create and add
a fully featured helper to set up the ACLs on file creation that
uses get_acl().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Rename the current posix_acl_chmod to __posix_acl_chmod and add
a fully featured ACL chmod helper that uses the ->set_acl inode
operation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The deadlock is found through the following scenario.
sys_mkdir()
-> f2fs_add_link()
-> __f2fs_add_link()
-> init_inode_metadata()
: lock_page(inode);
-> f2fs_init_acl()
-> f2fs_set_acl()
-> f2fs_setxattr(..., NULL)
: This NULL page incurs a deadlock at update_inode_page().
So, likewise f2fs_init_security(), this patch adds a parameter to transfer the
locked inode page to f2fs_setxattr().
Found by Linux File System Verification project (linuxtesting.org).
Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch adds the support of security labels for f2fs, which will be used
by Linus Security Models (LSMs).
Quote from http://en.wikipedia.org/wiki/Linux_Security_Modules:
"Linux Security Modules (LSM) is a framework that allows the Linux kernel to
support a variety of computer security models while avoiding favoritism toward
any single security implementation. The framework is licensed under the terms of
the GNU General Public License and is standard part of the Linux kernel since
Linux 2.6. AppArmor, SELinux, Smack and TOMOYO Linux are the currently accepted
modules in the official kernel.".
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
With user namespaces enabled building f2fs fails with:
CC fs/f2fs/acl.o
fs/f2fs/acl.c: In function ‘f2fs_acl_from_disk’:
fs/f2fs/acl.c:85:21: error: ‘struct posix_acl_entry’ has no member named ‘e_id’
make[2]: *** [fs/f2fs/acl.o] Error 1
make[2]: Target `__build' not remade because of errors.
e_id is a backwards compatibility field only used for file systems
that haven't been converted to use kuids and kgids. When the posix
acl tag field is neither ACL_USER nor ACL_GROUP assigning e_id is
unnecessary. Remove the assignment so f2fs will build with user
namespaces enabled.
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There exist two build failures reported by Randy Dunlap as follows.
(on i386)
a. (config-r8857)
ERROR: "f2fs_xattr_advise_handler" [fs/f2fs/f2fs.ko] undefined!
Key configs in (config-r8857) are as follows.
CONFIG_F2FS_FS=m
# CONFIG_F2FS_STAT_FS is not set
CONFIG_F2FS_FS_XATTR=y
# CONFIG_F2FS_FS_POSIX_ACL is not set
The error was occurred due to the function location that we made a mistake.
Recently we added a new functionality for users to indicate cold files
explicitly through xattr operations (i.e., f2fs_xattr_advise_handler).
This handler should have been added in xattr.c instead of acl.c in order
to avoid an undefined operation like in this case where XATTR is set and
ACL is not set.
b. (config-r8855)
fs/f2fs/file.c: In function 'f2fs_vm_page_mkwrite':
fs/f2fs/file.c:97:2: error: implicit declaration of function
'block_page_mkwrite_return'
Key config in (config-r8855) is CONFIG_BLOCK.
Obviously, f2fs works on top of the block device so that we should consider
carefully a sort of config dependencies.
The reason why this error was occurred was that f2fs_vm_page_mkwrite() calls
block_page_mkwrite_return() which is enalbed only if CONFIG_BLOCK is set.
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This implements xattr and acl functionalities.
- F2FS uses a node page to contain use extended attributes.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
