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-rw-r--r--fs/ntfs/mft.c29
1 files changed, 19 insertions, 10 deletions
diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c
index 3d0ba8e..ac9ff39 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
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