[PATCH REPOST] ntfs: don't disable interrupts during kmap_atomic()

From: Sebastian Andrzej Siewior
Date: Mon Jun 11 2018 - 10:49:20 EST


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.

Cc: Anton Altaparmakov <anton@xxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
Repost from
https://lkml.kernel.org/r/20180504144222.5443-1-bigeasy@xxxxxxxxxxxxx

fs/ntfs/aops.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 3a2e509c77c5..01c770979921 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -93,13 +93,11 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
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(struct buffer_head *bh, int uptodate)
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);
--
2.17.1