f2fs: vm_unmap_ram() may be called from an invalid context

In the Linux kernel, the following vulnerability has been resolved:

f2fs: vm_unmap_ram() may be called from an invalid context

When testing F2FS with xfstests using UFS backed virtual disks the
kernel complains sometimes that f2fs_release_decomp_mem() calls
vm_unmap_ram() from an invalid context. Example trace from
f2fs/007 test:

f2fs/007 5s ... [12:59:38][ 8.902525] run fstests f2fs/007
[ 11.468026] BUG: sleeping function called from invalid context at mm/vmalloc.c:2978
[ 11.471849] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 68, name: irq/22-ufshcd
[ 11.475357] preempt_count: 1, expected: 0
[ 11.476970] RCU nest depth: 0, expected: 0
[ 11.478531] CPU: 0 UID: 0 PID: 68 Comm: irq/22-ufshcd Tainted: G W 6.16.0-rc5-xfstests-ufs-g40f92e79b0aa #9 PREEMPT(none)
[ 11.478535] Tainted: [W]=WARN
[ 11.478536] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 11.478537] Call Trace:
[ 11.478543] <TASK>
[ 11.478545] dump_stack_lvl+0x4e/0x70
[ 11.478554] __might_resched.cold+0xaf/0xbe
[ 11.478557] vm_unmap_ram+0x21/0xb0
[ 11.478560] f2fs_release_decomp_mem+0x59/0x80
[ 11.478563] f2fs_free_dic+0x18/0x1a0
[ 11.478565] f2fs_finish_read_bio+0xd7/0x290
[ 11.478570] blk_update_request+0xec/0x3b0
[ 11.478574] ? sbitmap_queue_clear+0x3b/0x60
[ 11.478576] scsi_end_request+0x27/0x1a0
[ 11.478582] scsi_io_completion+0x40/0x300
[ 11.478583] ufshcd_mcq_poll_cqe_lock+0xa3/0xe0
[ 11.478588] ufshcd_sl_intr+0x194/0x1f0
[ 11.478592] ufshcd_threaded_intr+0x68/0xb0
[ 11.478594] ? __pfx_irq_thread_fn+0x10/0x10
[ 11.478599] irq_thread_fn+0x20/0x60
[ 11.478602] ? __pfx_irq_thread_fn+0x10/0x10
[ 11.478603] irq_thread+0xb9/0x180
[ 11.478605] ? __pfx_irq_thread_dtor+0x10/0x10
[ 11.478607] ? __pfx_irq_thread+0x10/0x10
[ 11.478609] kthread+0x10a/0x230
[ 11.478614] ? __pfx_kthread+0x10/0x10
[ 11.478615] ret_from_fork+0x7e/0xd0
[ 11.478619] ? __pfx_kthread+0x10/0x10
[ 11.478621] ret_from_fork_asm+0x1a/0x30
[ 11.478623] </TASK>

This patch modifies in_task() check inside f2fs_read_end_io() to also
check if interrupts are disabled. This ensures that pages are unmapped
asynchronously in an interrupt handler.