forked from Minki/linux
mainlining shenanigans
a801fcfeef
xfstests-generic/476 reports a warning message as below:
WARNING: CPU: 2 PID: 30347 at fs/inode.c:361 inc_nlink+0x52/0x70
Call Trace:
do_rename+0x502/0xd40 [ubifs]
ubifs_rename+0x8b/0x180 [ubifs]
vfs_rename+0x476/0x1080
do_renameat2+0x67c/0x7b0
__x64_sys_renameat2+0x6e/0x90
do_syscall_64+0x66/0xe0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Following race case can cause this:
rename_whiteout(Thread 1) wb_workfn(Thread 2)
ubifs_rename
do_rename
__writeback_single_inode
spin_lock(&inode->i_lock)
whiteout->i_state |= I_LINKABLE
inode->i_state &= ~dirty;
---- How race happens on i_state:
(tmp = whiteout->i_state | I_LINKABLE)
(tmp = inode->i_state & ~dirty)
(whiteout->i_state = tmp)
(inode->i_state = tmp)
----
spin_unlock(&inode->i_lock)
inc_nlink(whiteout)
WARN_ON(!(inode->i_state & I_LINKABLE)) !!!
Fix to add i_lock to avoid i_state update race condition.
Fixes:
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---|---|---|
arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.