Re: [PATCH] iomap: fix lockdep complaint when reads fail

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Mar 24, 2026 at 09:15:10AM +0100, Christian Brauner wrote:
> On Mon, 23 Mar 2026 14:00:17 -0700, Darrick J. Wong wrote:
> > Zorro Lang reported the following lockdep splat:
> > 
> > "While running fstests xfs/556 on kernel 7.0.0-rc4+ (HEAD=04a9f1766954),
> > a lockdep warning was triggered indicating an inconsistent lock state
> > for sb->s_type->i_lock_key.
> > 
> > "The deadlock might occur because iomap_read_end_io (called from a
> > hardware interrupt completion path) invokes fserror_report, which then
> > calls igrab.  igrab attempts to acquire the i_lock spinlock. However,
> > the i_lock is frequently acquired in process context with interrupts
> > enabled. If an interrupt occurs while a process holds the i_lock, and
> > that interrupt handler calls fserror_report, the system deadlocks.
> > 
> > [...]
> 
> Applied to the vfs.fixes branch of the vfs/vfs.git tree.
> Patches in the vfs.fixes branch should appear in linux-next soon.
> 
> Please report any outstanding bugs that were missed during review in a
> new review to the original patch series allowing us to drop it.
> 
> It's encouraged to provide Acked-bys and Reviewed-bys even though the
> patch has now been applied. If possible patch trailers will be updated.
> 
> Note that commit hashes shown below are subject to change due to rebase,
> trailer updates or similar. If in doubt, please check the listed branch.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
> branch: vfs.fixes
> 
> [1/1] iomap: fix lockdep complaint when reads fail

Hey Christian,

Is it not too late to rename this patch to:

"iomap: fix potential deadlock when buffered reads fail"

--D

>       https://git.kernel.org/vfs/vfs/c/f621324dfb3d