lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue,  4 Sep 2012 21:36:52 +0400
From:	Dmitry Monakhov <>
Cc:, Dmitry Monakhov <>
Subject: [PATCH 2/4] ext4: serialize unlocked dio reads with truncate

Current serialization will works only for DIO which holds
i_mutex, but nonlocked DIO following race is possible:

dio_nolock_read_task            truncate_task
				 #alloc truncated blocks
				 #to other inode

In order to serialize with unlocked DIO reads we have to
rearrange wait sequence
1) update i_size first
2) wait for outstanding DIO requests
3) and only after that truncate inode blocks

Reviewed-by: Jan Kara <>
Signed-off-by: Dmitry Monakhov <>
 fs/ext4/inode.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 58ef61a..709ec5a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4304,7 +4304,6 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 	if (attr->ia_valid & ATTR_SIZE) {
-		inode_dio_wait(inode);
 		if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 			struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -4355,6 +4354,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 	if (attr->ia_valid & ATTR_SIZE) {
 		if (attr->ia_size != i_size_read(inode))
 			truncate_setsize(inode, attr->ia_size);
+		inode_dio_wait(inode);

To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists