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Date: Wed, 25 Mar 2020 13:28:23 +0100
From: Christoph Hellwig <hch@....de>
To: "Theodore Ts'o" <tytso@....edu>, Jaegeuk Kim <jaegeuk@...nel.org>,
Chao Yu <chao@...nel.org>, Al Viro <viro@...iv.linux.org.uk>,
Richard Weinberger <richard@....at>, linux-xfs@...r.kernel.org
Cc: Eric Biggers <ebiggers@...nel.org>, linux-ext4@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net,
linux-fsdevel@...r.kernel.org, linux-mtd@...ts.infradead.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 2/4] fs: avoid double-writing the inode on a lazytime expiration
In the case that an inode has dirty timestamp for longer than the
lazytime expiration timeout (or if all such inodes are being flushed
out due to a sync or syncfs system call), we need to inform the file
system that the inode is dirty so that the inode's timestamps can be
copied out to the on-disk data structures. That's because if the file
system supports lazytime, it will have ignored the dirty_inode(inode,
I_DIRTY_TIME) notification when the timestamp was modified in memory.q
Previously, this was accomplished by calling mark_inode_dirty_sync(),
but that has the unfortunate side effect of also putting the inode the
writeback list, and that's not necessary in this case, since we will
immediately call write_inode() afterwards. Replace the call to
mark_inode_dirty_sync() with a new lazytime_expired method to clearly
separate out this case.
Eric Biggers noticed that this was causing problems for fscrypt after
the key was removed[1].
Based on a patch from Theodore Ts'o.
[1] https://lore.kernel.org/r/20200306004555.GB225345@gmail.com
Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option")
Reported-by: Eric Biggers <ebiggers@...nel.org>
Signed-off-by: Christoph Hellwig <hch@....de>
---
fs/ext4/super.c | 6 ++++++
fs/f2fs/super.c | 6 ++++++
fs/fs-writeback.c | 3 ++-
fs/inode.c | 3 ++-
fs/xfs/xfs_super.c | 12 +++---------
include/linux/fs.h | 1 +
6 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0c7c4adb664e..ebbf6370ccd6 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1448,6 +1448,11 @@ static struct dquot **ext4_get_dquots(struct inode *inode)
return EXT4_I(inode)->i_dquot;
}
+static void ext4_lazytime_expired(struct inode *inode)
+{
+ return ext4_dirty_inode(inode, I_DIRTY_SYNC);
+}
+
static const struct dquot_operations ext4_quota_operations = {
.get_reserved_space = ext4_get_reserved_space,
.write_dquot = ext4_write_dquot,
@@ -1480,6 +1485,7 @@ static const struct super_operations ext4_sops = {
.destroy_inode = ext4_destroy_inode,
.write_inode = ext4_write_inode,
.dirty_inode = ext4_dirty_inode,
+ .lazytime_expired = ext4_lazytime_expired,
.drop_inode = ext4_drop_inode,
.evict_inode = ext4_evict_inode,
.put_super = ext4_put_super,
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 65a7a432dfee..529334573944 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1100,6 +1100,11 @@ static void f2fs_dirty_inode(struct inode *inode, int flags)
f2fs_inode_dirtied(inode, false);
}
+static void f2fs_lazytime_expired(struct inode *inode)
+{
+ return f2fs_dirty_inode(inode, I_DIRTY_SYNC);
+}
+
static void f2fs_free_inode(struct inode *inode)
{
fscrypt_free_inode(inode);
@@ -2355,6 +2360,7 @@ static const struct super_operations f2fs_sops = {
.drop_inode = f2fs_drop_inode,
.write_inode = f2fs_write_inode,
.dirty_inode = f2fs_dirty_inode,
+ .lazytime_expired = f2fs_lazytime_expired,
.show_options = f2fs_show_options,
#ifdef CONFIG_QUOTA
.quota_read = f2fs_quota_read,
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 76ac9c7d32ec..dc2d65c765ae 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1505,7 +1505,8 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
spin_unlock(&inode->i_lock);
if (dirty & I_DIRTY_TIME)
- mark_inode_dirty_sync(inode);
+ inode->i_sb->s_op->lazytime_expired(inode);
+
/* Don't write the inode if only I_DIRTY_PAGES was set */
if (dirty & ~I_DIRTY_PAGES) {
int err = write_inode(inode, wbc);
diff --git a/fs/inode.c b/fs/inode.c
index 93d9252a00ab..96cf26ed4c7b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1674,7 +1674,8 @@ int generic_update_time(struct inode *inode, struct timespec64 *time, int flags)
if (flags & S_MTIME)
inode->i_mtime = *time;
if ((flags & (S_ATIME | S_CTIME | S_MTIME)) &&
- !(inode->i_sb->s_flags & SB_LAZYTIME))
+ (!inode->i_sb->s_op->lazytime_expired ||
+ !(inode->i_sb->s_flags & SB_LAZYTIME)))
dirty = true;
if (dirty)
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 2094386af8ac..e5aafd40dd0f 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -612,19 +612,13 @@ xfs_fs_destroy_inode(
}
static void
-xfs_fs_dirty_inode(
- struct inode *inode,
- int flag)
+xfs_fs_lazytime_expired(
+ struct inode *inode)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
- if (!(inode->i_sb->s_flags & SB_LAZYTIME))
- return;
- if (flag != I_DIRTY_SYNC || !(inode->i_state & I_DIRTY_TIME))
- return;
-
if (xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp))
return;
xfs_ilock(ip, XFS_ILOCK_EXCL);
@@ -1053,7 +1047,7 @@ xfs_fs_free_cached_objects(
static const struct super_operations xfs_super_operations = {
.alloc_inode = xfs_fs_alloc_inode,
.destroy_inode = xfs_fs_destroy_inode,
- .dirty_inode = xfs_fs_dirty_inode,
+ .lazytime_expired = xfs_fs_lazytime_expired,
.drop_inode = xfs_fs_drop_inode,
.put_super = xfs_fs_put_super,
.sync_fs = xfs_fs_sync_fs,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index abedbffe2c9e..07c213cdecf3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1948,6 +1948,7 @@ struct super_operations {
int (*write_inode) (struct inode *, struct writeback_control *wbc);
int (*drop_inode) (struct inode *);
void (*evict_inode) (struct inode *);
+ void (*lazytime_expired)(struct inode *inode);
void (*put_super) (struct super_block *);
int (*sync_fs)(struct super_block *sb, int wait);
int (*freeze_super) (struct super_block *);
--
2.25.1
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