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>

1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 7c5e29eaf11..89193104c6c 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -157,7 +157,7 @@ static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id,
 {
         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 @@ int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
 
 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 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
         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 @@ int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
          * 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 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
         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 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
         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;