Currently, filesystem can indiate cgroup writeback support per
superblock; however, depending on the filesystem, especially if inodes
are used to carry metadata, it can be useful to indicate cgroup
writeback support per inode.
This patch replaces the superblock flag SB_I_CGROUPWB with per-inode
S_CGROUPWB, so that cgroup writeback can be enabled selectively.
* block_dev sets the new flag in bdget() when initializing new inode.
* ext2 sets the new flag in ext2_set_inode_flags().
* ext4 sets the new flag in ext4_set_inode_flags() if
!ext4_should_journal_data(inode). This makes inodes whose data is
journalled due to inode flags to bypass cgroup writeback. This
behavior change is intended.
* btrfs sets the new flag in btrfs_update_iflags() function. Note
that this automatically excludes btree_inode which doesn't use
btrfs_update_iflags() during initialization. This behavior change
is intended.
v2: Use ext4_should_journal_data() as suggested by Jan.
Signed-off-by: Tejun Heo <t...@kernel.org>
Reviewed-by: Jan Kara <j...@suse.cz>
Cc: Jens Axboe <ax...@kernel.dk>
Cc: Chris Mason <c...@fb.com>
Cc: Josef Bacik <jba...@fb.com>
Cc: linux-btrfs@vger.kernel.org
Cc: "Theodore Ts'o" <ty...@mit.edu>
Cc: Andreas Dilger <adilger.ker...@dilger.ca>
Cc: linux-e...@vger.kernel.org
---
fs/block_dev.c | 3 +--
fs/btrfs/ioctl.c | 4 +++-
fs/btrfs/super.c | 1 -
fs/ext2/inode.c | 3 ++-
fs/ext2/super.c | 1 -
fs/ext4/inode.c | 5 ++++-
fs/ext4/super.c | 2 --
include/linux/backing-dev.h | 2 +-
include/linux/fs.h | 3 ++-
9 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 93d088f..ff9c282 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -800,8 +800,6 @@ static struct dentry *bd_mount(struct file_system_type
*fs_type,
{
struct dentry *dent;
dent = mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC);
- if (!IS_ERR(dent))
- dent->d_sb->s_iflags |= SB_I_CGROUPWB;
return dent;
}
@@ -893,6 +891,7 @@ struct block_device *bdget(dev_t dev)
inode->i_mode = S_IFBLK;
inode->i_rdev = dev;
inode->i_bdev = bdev;
+ inode->i_flags |= S_CGROUPWB;
inode->i_data.a_ops = &def_blk_aops;
mapping_set_gfp_mask(&inode->i_data, GFP_USER);
spin_lock(&bdev_lock);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 6c7a49f..117cc63 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -150,9 +150,11 @@ void btrfs_update_iflags(struct inode *inode)
new_fl |= S_NOATIME;
if (ip->flags & BTRFS_INODE_DIRSYNC)
new_fl |= S_DIRSYNC;
+ new_fl |= S_CGROUPWB;
set_mask_bits(&inode->i_flags,
- S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
+ S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
+ S_CGROUPWB,
new_fl);
}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 35a128a..46a1488 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1136,7 +1136,6 @@ static int btrfs_fill_super(struct super_block *sb,
sb->s_flags |= MS_POSIXACL;
#endif
sb->s_flags |= MS_I_VERSION;
- sb->s_iflags |= SB_I_CGROUPWB;
err = super_setup_bdi(sb);
if (err) {
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 4dca6f3..3c5d822 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1372,7 +1372,7 @@ void ext2_set_inode_flags(struct inode *inode)
unsigned int flags = EXT2_I(inode)->i_flags;
inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
- S_DIRSYNC | S_DAX);
+ S_DIRSYNC | S_DAX | S_CGROUPWB);
if (flags & EXT2_SYNC_FL)
inode->i_flags |= S_SYNC;
if (flags & EXT2_APPEND_FL)
@@ -1385,6 +1385,7 @@ void ext2_set_inode_flags(struct inode *inode)
inode->i_flags |= S_DIRSYNC;
if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
inode->i_flags |= S_DAX;
+ inode->i_flags |= S_CGROUPWB;
}
struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 1458706..e6ba669e 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -922,7 +922,6 @@ static int ext2_fill_super(struct super_block *sb, void
*data, int silent)
sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
MS_POSIXACL : 0);
- sb->s_iflags |= SB_I_CGROUPWB;
if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
(EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875..d92c356 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4591,8 +4591,11 @@ void ext4_set_inode_flags(struct inode *inode)
!ext4_should_journal_data(inode) && !ext4_has_inline_data(inode) &&
!ext4_encrypted_inode(inode))
new_fl |= S_DAX;
+ if (!ext4_should_journal_data(inode))
+ new_fl |= S_CGROUPWB;
inode_set_flags(inode, new_fl,
- S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);
+ S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX|
+ S_CGROUPWB);
}
static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b104096..44ddf1d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3620,8 +3620,6 @@ static int ext4_fill_super(struct super_block *sb, void
*data, int silent)
}
if (test_opt(sb, DELALLOC))
clear_opt(sb, DELALLOC);
- } else {
- sb->s_iflags |= SB_I_CGROUPWB;
}
sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 854e1bd..7274de0 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -246,7 +246,7 @@ static inline bool inode_cgwb_enabled(struct inode *inode)
cgroup_subsys_on_dfl(io_cgrp_subsys) &&
bdi_cap_account_dirty(bdi) &&
(bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
- (inode->i_sb->s_iflags & SB_I_CGROUPWB);
+ IS_CGROUPWB(inode);
}
/**
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab19..be2d8a6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1308,7 +1308,6 @@ extern int send_sigurg(struct fown_struct *fown);
#define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */
/* sb->s_iflags */
-#define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */
#define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */
#define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */
@@ -1853,6 +1852,7 @@ struct super_operations {
#else
#define S_DAX 0 /* Make all the DAX code disappear */
#endif
+#define S_CGROUPWB 16384 /* Enable cgroup writeback for this inode */
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
@@ -1892,6 +1892,7 @@ static inline bool sb_rdonly(const struct super_block
*sb) { return sb->s_flags
#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT)
#define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC)
#define IS_DAX(inode) ((inode)->i_flags & S_DAX)
+#define IS_CGROUPWB(inode) ((inode)->i_flags & S_CGROUPWB)
#define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \
(inode)->i_rdev == WHITEOUT_DEV)
--
2.9.5
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