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/wl.c b/drivers/mtd/ubi/wl.c
index 12b25e5..248ff9e 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -508,7 +508,7 @@
ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM ||
dtype == UBI_UNKNOWN);
- pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_KERNEL);
+ pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
if (!pe)
return -ENOMEM;
@@ -645,7 +645,7 @@
if (err > 0)
return -EINVAL;
- ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
if (!ec_hdr)
return -ENOMEM;
@@ -768,7 +768,7 @@
dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
e->pnum, e->ec, torture);
- wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_KERNEL);
+ wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
if (!wl_wrk)
return -ENOMEM;
@@ -802,7 +802,7 @@
if (cancel)
return 0;
- vid_hdr = ubi_zalloc_vid_hdr(ubi);
+ vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
return -ENOMEM;
@@ -1028,7 +1028,7 @@
ubi->wl_scheduled = 1;
spin_unlock(&ubi->wl_lock);
- wrk = kmalloc(sizeof(struct ubi_work), GFP_KERNEL);
+ wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
if (!wrk) {
err = -ENOMEM;
goto out_cancel;
@@ -1631,7 +1631,7 @@
long long read_ec;
struct ubi_ec_hdr *ec_hdr;
- ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
if (!ec_hdr)
return -ENOMEM;