From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> mainline inclusion from mainline-v6.12-rc1 commit 6dfc1c1d597f8b6ebffe25f51f013494994f9b84 category: feature bugzilla: https://atomgit.com/src-openeuler/kernel/issues/8862 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- This patch adds base support for atomic writes via statx getattr. On bs < ps systems, we can create FS with say bs of 16k. That means both atomic write min and max unit can be set to 16k for supporting atomic writes. Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Conflicts: fs/ext4/ext4.h [Context conflicts] Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/ext4/ext4.h | 10 ++++++++++ fs/ext4/inode.c | 12 ++++++++++++ fs/ext4/super.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 53 insertions(+) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index baa94e1937c3..fed0e5986adb 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1727,6 +1727,10 @@ struct ext4_sb_info { */ struct work_struct s_sb_upd_work; + /* Atomic write unit values in bytes */ + unsigned int s_awu_min; + unsigned int s_awu_max; + /* Ext4 fast commit sub transaction ID */ atomic_t s_fc_subtid; @@ -3867,6 +3871,12 @@ static inline int ext4_buffer_uptodate(struct buffer_head *bh) return buffer_uptodate(bh); } +static inline bool ext4_inode_can_atomic_write(struct inode *inode) +{ + + return S_ISREG(inode->i_mode) && EXT4_SB(inode->i_sb)->s_awu_min > 0; +} + #endif /* __KERNEL__ */ #define EFSBADCRC EBADMSG /* Bad CRC detected */ diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 26de65393ef7..729ed40b1d47 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -6440,6 +6440,18 @@ int ext4_getattr(struct mnt_idmap *idmap, const struct path *path, } } + if ((request_mask & STATX_WRITE_ATOMIC) && S_ISREG(inode->i_mode)) { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + unsigned int awu_min = 0, awu_max = 0; + + if (ext4_inode_can_atomic_write(inode)) { + awu_min = sbi->s_awu_min; + awu_max = sbi->s_awu_max; + } + + generic_fill_statx_atomic_writes(stat, awu_min, awu_max); + } + flags = ei->i_flags & EXT4_FL_USER_VISIBLE; if (flags & EXT4_APPEND_FL) stat->attributes |= STATX_ATTR_APPEND; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index e616d63b5a5e..8bfa85c57022 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4582,6 +4582,36 @@ static int ext4_handle_clustersize(struct super_block *sb) return 0; } +/* + * ext4_atomic_write_init: Initializes filesystem min & max atomic write units. + * @sb: super block + * TODO: Later add support for bigalloc + */ +static void ext4_atomic_write_init(struct super_block *sb) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct block_device *bdev = sb->s_bdev; + + if (!bdev_can_atomic_write(bdev)) + return; + + if (!ext4_has_feature_extents(sb)) + return; + + sbi->s_awu_min = max(sb->s_blocksize, + bdev_atomic_write_unit_min_bytes(bdev)); + sbi->s_awu_max = min(sb->s_blocksize, + bdev_atomic_write_unit_max_bytes(bdev)); + if (sbi->s_awu_min && sbi->s_awu_max && + sbi->s_awu_min <= sbi->s_awu_max) { + ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u", + sbi->s_awu_min, sbi->s_awu_max); + } else { + sbi->s_awu_min = 0; + sbi->s_awu_max = 0; + } +} + static void ext4_fast_commit_init(struct super_block *sb) { struct ext4_sb_info *sbi = EXT4_SB(sb); @@ -5487,6 +5517,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) spin_lock_init(&sbi->s_bdev_wb_lock); + ext4_atomic_write_init(sb); ext4_fast_commit_init(sb); sb->s_root = NULL; -- 2.52.0