Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "This merge window, we've added some performance improvements in how we
  handle inode locking in the read/write paths, and improving the
  performance of Direct I/O overwrites.

  We also now record the error code which caused the first and most
  recent ext4_error() report in the superblock, to make it easier to
  root cause problems in production systems.

  There are also many of the usual cleanups and miscellaneous bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (49 commits)
  jbd2: clean __jbd2_journal_abort_hard() and __journal_abort_soft()
  jbd2: make sure ESHUTDOWN to be recorded in the journal superblock
  ext4, jbd2: ensure panic when aborting with zero errno
  jbd2: switch to use jbd2_journal_abort() when failed to submit the commit record
  jbd2_seq_info_next should increase position index
  jbd2: remove pointless assertion in __journal_remove_journal_head
  ext4,jbd2: fix comment and code style
  jbd2: delete the duplicated words in the comments
  ext4: fix extent_status trace points
  ext4: fix symbolic enum printing in trace output
  ext4: choose hardlimit when softlimit is larger than hardlimit in ext4_statfs_project()
  ext4: fix race conditions in ->d_compare() and ->d_hash()
  ext4: make dioread_nolock the default
  ext4: fix extent_status fragmentation for plain files
  jbd2: clear JBD2_ABORT flag before journal_reset to update log tail info when load journal
  ext4: drop ext4_kvmalloc()
  ext4: Add EXT4_IOC_FSGETXATTR/EXT4_IOC_FSSETXATTR to compat_ioctl
  ext4: remove unused macro MPAGE_DA_EXTENT_TAIL
  ext4: add missing braces in ext4_ext_drop_refs()
  ext4: fix some nonstandard indentation in extents.c
  ...

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 4e093277c8bf..1f340743c9a8 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -462,7 +462,6 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 	new_fn->name_len = ent_name->len;
 	new_fn->file_type = dirent->file_type;
 	memcpy(new_fn->name, ent_name->name, ent_name->len);
-	new_fn->name[ent_name->len] = 0;
 
 	while (*p) {
 		parent = *p;
@@ -672,9 +671,11 @@ static int ext4_d_compare(const struct dentry *dentry, unsigned int len,
 			  const char *str, const struct qstr *name)
 {
 	struct qstr qstr = {.name = str, .len = len };
-	struct inode *inode = dentry->d_parent->d_inode;
+	const struct dentry *parent = READ_ONCE(dentry->d_parent);
+	const struct inode *inode = READ_ONCE(parent->d_inode);
 
-	if (!IS_CASEFOLDED(inode) || !EXT4_SB(inode->i_sb)->s_encoding) {
+	if (!inode || !IS_CASEFOLDED(inode) ||
+	    !EXT4_SB(inode->i_sb)->s_encoding) {
 		if (len != name->len)
 			return -1;
 		return memcmp(str, name->name, len);
@@ -687,10 +688,11 @@ static int ext4_d_hash(const struct dentry *dentry, struct qstr *str)
 {
 	const struct ext4_sb_info *sbi = EXT4_SB(dentry->d_sb);
 	const struct unicode_map *um = sbi->s_encoding;
+	const struct inode *inode = READ_ONCE(dentry->d_inode);
 	unsigned char *norm;
 	int len, ret = 0;
 
-	if (!IS_CASEFOLDED(dentry->d_inode) || !um)
+	if (!inode || !IS_CASEFOLDED(inode) || !um)
 		return 0;
 
 	norm = kmalloc(PATH_MAX, GFP_ATOMIC);