UBI: allocate memory with GFP_NOFS
Use GFP_NOFS flag when allocating memory on I/O path, because otherwise
we may deadlock the filesystem which works on top of us. We observed
the deadlocks with UBIFS. Example:
VFS->FS lock a lock->UBI->kmalloc()->VFS writeback->FS locks the same
lock again.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 7c5e29e..8919310 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -157,7 +157,7 @@
{
struct ltree_entry *le, *le1, *le_free;
- le = kmem_cache_alloc(ltree_slab, GFP_KERNEL);
+ le = kmem_cache_alloc(ltree_slab, GFP_NOFS);
if (!le)
return ERR_PTR(-ENOMEM);
@@ -397,7 +397,7 @@
retry:
if (check) {
- vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr) {
err = -ENOMEM;
goto out_unlock;
@@ -497,7 +497,7 @@
struct ubi_vid_hdr *vid_hdr;
unsigned char *new_buf;
- vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr) {
return -ENOMEM;
}
@@ -627,7 +627,7 @@
* The logical eraseblock is not mapped. We have to get a free physical
* eraseblock and write the volume identifier header there first.
*/
- vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr) {
leb_write_unlock(ubi, vol_id, lnum);
return -ENOMEM;
@@ -738,7 +738,7 @@
else
ubi_assert(len % ubi->min_io_size == 0);
- vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
return -ENOMEM;
@@ -844,7 +844,7 @@
if (ubi->ro_mode)
return -EROFS;
- vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
return -ENOMEM;