Dear Jaegeuk,
Testing F2FS in the following configuration:
CONFIG_F2FS_FS=m
CONFIG_F2FS_STAT_FS=y
CONFIG_F2FS_FS_XATTR=y
CONFIG_F2FS_FS_POSIX_ACL=y
CONFIG_F2FS_FS_SECURITY=y
I have got a deadlock:
[16921.437845] INFO: task fs-driver-tests:12695 blocked for more than
120 seconds.
[16921.437899] Tainted: G W 3.12-rc6-284-generic #1
[16921.437941] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[16921.437980] fs-driver-tests D ffff88007dd3fb78 0 12695 12361
0x00000000
[16921.438017] ffff88007dd3fae8 0000000000000092 ffff880036c4bfa0
ffff88007dd3ffd8
[16921.438049] ffff88007dd3ffd8 ffff88007dd3ffd8 ffffffff81c104e0
ffff880036c4bfa0
[16921.438078] ffff880036c4bfa0 ffff880082a14858 0000000000000002
ffffffff8113f600
[16921.438106] Call Trace:
[16921.438156] [<ffffffff8113f600>] ? __lock_page+0x70/0x70
[16921.438196] [<ffffffff8165e599>] schedule+0x29/0x70
[16921.438229] [<ffffffff8165e66f>] io_schedule+0x8f/0xd0
[16921.438257] [<ffffffff8113f60e>] sleep_on_page+0xe/0x20
[16921.438281] [<ffffffff8165a53d>] __wait_on_bit_lock+0x5d/0xc0
[16921.438302] [<ffffffff8113f5f7>] __lock_page+0x67/0x70
[16921.438323] [<ffffffff81077760>] ? wake_atomic_t_function+0x40/0x40
[16921.438340] [<ffffffff811402b1>] find_lock_page+0x61/0x90
[16921.438355] [<ffffffff8114040f>] find_or_create_page+0x3f/0xb0
[16921.438375] [<ffffffffa02b6979>] get_node_page+0x39/0x180 [f2fs]
[16921.438398] [<ffffffffa02aa723>] update_inode_page+0x23/0x70 [f2fs]
[16921.438412] [<ffffffffa02b6da8>] sync_inode_page+0xd8/0xe0 [f2fs]
[16921.438425] [<ffffffffa02b7068>] new_node_page+0x2b8/0x2e0 [f2fs]
[16921.438438] [<ffffffffa02c0c2c>] f2fs_setxattr+0x44c/0x650 [f2fs]
[16921.438451] [<ffffffffa02c1205>] f2fs_set_acl+0x235/0x350 [f2fs]
[16921.438462] [<ffffffffa02c179a>] ? f2fs_get_acl+0x8a/0xc0 [f2fs]
[16921.438473] [<ffffffffa02c19d0>] f2fs_init_acl+0x140/0x170 [f2fs]
[16921.438483] [<ffffffffa02a7a46>] __f2fs_add_link+0x276/0x720 [f2fs]
[16921.438494] [<ffffffffa02ab866>] f2fs_mkdir+0x116/0x1b0 [f2fs]
[16921.438503] [<ffffffff811ab744>] ? __inode_permission+0x64/0xe0
[16921.438512] [<ffffffff811aecf6>] vfs_mkdir+0xa6/0x130
[16921.438521] [<ffffffff811b0d2a>] SyS_mkdirat+0xaa/0xf0
[16921.438530] [<ffffffff811b0d89>] SyS_mkdir+0x19/0x20
[16921.438540] [<ffffffff81668e92>] system_call_fastpath+0x16/0x1b
[16921.438545] 4 locks held by fs-driver-tests/12695:
[16921.438550] #0: (sb_writers#11){.+.+.+}, at: [<ffffffff811c0504>]
mnt_want_write+0x24/0x50
[16921.438559] #1: (&type->i_mutex_dir_key#3/1){+.+.+.}, at:
[<ffffffff811acec7>] kern_path_create+0x87/0x170
[16921.438567] #2: (&sbi->fs_lock[i]){+.+.+.}, at:
[<ffffffffa02ab81c>] f2fs_mkdir+0xcc/0x1b0 [f2fs]
[16921.438576] #3: (&sbi->fs_lock[i]){+.+.+.}, at:
[<ffffffffa02c08a4>] f2fs_setxattr+0xc4/0x650 [f2fs]
Analysis shown the following problem:
sys_mkdir() calls
-> f2fs_add_link()
-> __f2fs_add_link()
-> init_inode_metadata():
static struct page *init_inode_metadata(struct inode *inode,
struct inode *dir, const struct qstr *name)
{
struct page *page;
int err;
if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
page = new_inode_page(inode, name); <--- NEW PAGE CAME LOCKED HERE
if (IS_ERR(page))
return page;
if (S_ISDIR(inode->i_mode)) {
err = make_empty_dir(inode, dir, page);
if (err)
goto error;
}
err = f2fs_init_acl(inode, dir);
...........
return page;
PAGE IS RETURNED FROM init_inode_metadata() LOCKED
But
f2fs_init_acl() calls
-> f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
-> f2fs_setxattr(inode, ...)
-> write_all_xattrs(inode, ...)
-> new_node_page(&dn, ...), where dn->inode = inode
-> sync_inode_page(dn)
-> update_inode_page(dn->inode):
-> get_node_page(sbi, inode->i_ino):
struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
{
struct address_space *mapping = sbi->node_inode->i_mapping;
struct page *page;
int err;
repeat:
page = grab_cache_page(mapping, nid); <-- DEADLOCK: PAGE IS ALREADY
LOCKED
Found by Linux File System Verification project (linuxtesting.org).
--
Best regards,
Alexey Khoroshilov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org