From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Subject: fs/ntfs/aops.c: don't disable interrupts during kmap_atomic()
ntfs_end_buffer_async_read() disables interrupts around kmap_atomic().
This is a leftover from the old kmap_atomic() implementation which relied
on fixed mapping slots, so the caller had to make sure that the same slot
could not be reused from an interrupting context.
kmap_atomic() was changed to dynamic slots long ago and commit
1ec9c5ddc17a ("include/linux/highmem.h: remove the second argument of
k[un]map_atomic()") removed the slot assignements, but the callers were
not checked for now redundant interrupt disabling.
Remove the conditional interrupt disable.
Link: http://lkml.kernel.org/r/20180611144913.gln5mklhqcrfsoom@xxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Anton Altaparmakov <anton@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ntfs/aops.c | 4 ----
1 file changed, 4 deletions(-)
--- a/fs/ntfs/aops.c~ntfs-dont-disable-interrupts-during-kmap_atomic
+++ a/fs/ntfs/aops.c
@@ -93,13 +93,11 @@ static void ntfs_end_buffer_async_read(s
ofs = 0;
if (file_ofs < init_size)
ofs = init_size - file_ofs;
- local_irq_save(flags);
kaddr = kmap_atomic(page);
memset(kaddr + bh_offset(bh) + ofs, 0,
bh->b_size - ofs);
flush_dcache_page(page);
kunmap_atomic(kaddr);
- local_irq_restore(flags);
}
} else {
clear_buffer_uptodate(bh);
@@ -146,13 +144,11 @@ static void ntfs_end_buffer_async_read(s
recs = PAGE_SIZE / rec_size;
/* Should have been verified before we got here... */
BUG_ON(!recs);
- local_irq_save(flags);
kaddr = kmap_atomic(page);
for (i = 0; i < recs; i++)
post_read_mst_fixup((NTFS_RECORD*)(kaddr +
i * rec_size), rec_size);
kunmap_atomic(kaddr);
- local_irq_restore(flags);
flush_dcache_page(page);
if (likely(page_uptodate && !PageError(page)))
SetPageUptodate(page);
_
