1 files changed, 19 insertions, 10 deletions

diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
index 3d0ba8e60adc..ac9ff39aa834 100644
--- a/fs/ntfs/mft.c
+++ b/fs/ntfs/mft.c
@@ -948,20 +948,23 @@ BOOL ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no,
         na.name_len = 0;
         na.type = AT_UNUSED;
         /*
-         * For inode 0, i.e. $MFT itself, we cannot use ilookup5() from here or
-         * we deadlock because the inode is already locked by the kernel
-         * (fs/fs-writeback.c::__sync_single_inode()) and ilookup5() waits
-         * until the inode is unlocked before returning it and it never gets
-         * unlocked because ntfs_should_write_mft_record() never returns.  )-:
-         * Fortunately, we have inode 0 pinned in icache for the duration of
-         * the mount so we can access it directly.
+         * Optimize inode 0, i.e. $MFT itself, since we have it in memory and
+         * we get here for it rather often.
          */
         if (!mft_no) {
                 /* Balance the below iput(). */
                 vi = igrab(mft_vi);
                 BUG_ON(vi != mft_vi);
-        } else
-                vi = ilookup5(sb, mft_no, (test_t)ntfs_test_inode, &na);
+        } else {
+                /*
+                 * Have to use ilookup5_nowait() since ilookup5() waits for the
+                 * inode lock which causes ntfs to deadlock when a concurrent
+                 * inode write via the inode dirty code paths and the page
+                 * dirty code path of the inode dirty code path when writing
+                 * $MFT occurs.
+                 */
+                vi = ilookup5_nowait(sb, mft_no, (test_t)ntfs_test_inode, &na);
+        }
         if (vi) {
                 ntfs_debug("Base inode 0x%lx is in icache.", mft_no);
                 /* The inode is in icache. */
@@ -1016,7 +1019,13 @@ BOOL ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no,
         na.mft_no = MREF_LE(m->base_mft_record);
         ntfs_debug("Mft record 0x%lx is an extent record.  Looking for base "
                         "inode 0x%lx in icache.", mft_no, na.mft_no);
-        vi = ilookup5(sb, na.mft_no, (test_t)ntfs_test_inode, &na);
+        if (!na.mft_no) {
+                /* Balance the below iput(). */
+                vi = igrab(mft_vi);
+                BUG_ON(vi != mft_vi);
+        } else
+                vi = ilookup5_nowait(sb, na.mft_no, (test_t)ntfs_test_inode,
+                                &na);
         if (!vi) {
                 /*
                  * The base inode is not in icache, write this extent mft