On Mon, 29 Jan 2007 23:27:27 -0800
Andrew Morton <akpm@osdl.org> wrote:
Actually, this isn't related to softirq-vs-hardirq. Most interrupt
handlers are interruptible, so the rule is simply that KM_BIO_SRC_IRQ must
always be taken under local_irq_disable().
A quick scan indicates that the following files might be buggy in this
regard:
drivers/mmc/wbsd.c
drivers/mmc/at91_mci.c
drivers/mmc/sdhci.c
drivers/scsi/scsi_lib.c when called from stex.c
fs/ntfs/aops.c
Happily, KM_BIO_DST_IRQ has no users and can presumably be removed.
Fixes for stex and ntfs follow.
From: Andrew Morton <akpm@osdl.org>
The KM_BIO_SRC_IRQ kmap slot requires local irq protection.
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Ed Lin <ed.lin@promise.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
drivers/scsi/stex.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff -puN drivers/scsi/stex.c~stex-kmap_atomic-atomicity-fix drivers/scsi/stex.c
--- a/drivers/scsi/stex.c~stex-kmap_atomic-atomicity-fix
+++ a/drivers/scsi/stex.c
@@ -459,15 +459,19 @@ static void stex_internal_copy(struct sc
*count = cmd->request_bufflen;
lcount = *count;
while (lcount) {
+ unsigned long flags = flags; /* Suppress uninit warning */
+
len = lcount;
s = (void *)src;
if (cmd->use_sg) {
size_t offset = *count - lcount;
s += offset;
+ local_irq_save(flags);
base = scsi_kmap_atomic_sg(cmd->request_buffer,
sg_count, &offset, &len);
if (base == NULL) {
*count -= lcount;
+ local_irq_restore(flags);
return;
}
d = base + offset;
@@ -480,8 +484,10 @@ static void stex_internal_copy(struct sc
memcpy(s, d, len);
lcount -= len;
- if (cmd->use_sg)
+ if (cmd->use_sg) {
scsi_kunmap_atomic_sg(base);
+ local_irq_restore(flags);
+ }
}
}
_
From: Andrew Morton <akpm@osdl.org>
The KM_BIO_SRC_IRQ kmap slot requires local irq protection.
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
fs/ntfs/aops.c | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN fs/ntfs/aops.c~ntfs-kmap_atomic-atomicity-fix fs/ntfs/aops.c
--- a/fs/ntfs/aops.c~ntfs-kmap_atomic-atomicity-fix
+++ a/fs/ntfs/aops.c
@@ -88,14 +88,17 @@ static void ntfs_end_buffer_async_read(s
if (unlikely(file_ofs + bh->b_size > init_size)) {
u8 *kaddr;
int ofs;
+ unsigned long flags;
ofs = 0;
if (file_ofs < init_size)
ofs = init_size - file_ofs;
+ local_irq_save(flags);
kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
memset(kaddr + bh_offset(bh) + ofs, 0,
bh->b_size - ofs);
kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
+ local_irq_restore(flags);
flush_dcache_page(page);
}
} else {
@@ -138,16 +141,19 @@ static void ntfs_end_buffer_async_read(s
u8 *kaddr;
unsigned int i, recs;
u32 rec_size;
+ unsigned long flags;
rec_size = ni->itype.index.block_size;
recs = PAGE_CACHE_SIZE / rec_size;
/* Should have been verified before we got here... */
BUG_ON(!recs);
+ local_irq_save(flags);
kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
for (i = 0; i < recs; i++)
post_read_mst_fixup((NTFS_RECORD*)(kaddr +
i * rec_size), rec_size);
kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
+ local_irq_restore(flags);
flush_dcache_page(page);
if (likely(page_uptodate && !PageError(page)))
SetPageUptodate(page);
_
-
