Commit 1c9114f9 authored by Dmitry Monakhov's avatar Dmitry Monakhov Committed by Theodore Ts'o
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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) if i_size about to be reduced wait for outstanding DIO requests
3) and only after that truncate inode blocks

Reviewed-by: default avatarJan Kara <>
Signed-off-by: default avatarDmitry Monakhov <>
Signed-off-by: default avatar"Theodore Ts'o" <>
parent 17335dcc
......@@ -4283,7 +4283,6 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
if (attr->ia_valid & ATTR_SIZE) {
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
......@@ -4332,8 +4331,12 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
if (attr->ia_valid & ATTR_SIZE) {
if (attr->ia_size != i_size_read(inode))
if (attr->ia_size != i_size_read(inode)) {
truncate_setsize(inode, attr->ia_size);
/* Inode size will be reduced, wait for dio in flight */
if (orphan)
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