From 6432c6e723fffd93e5cb65117ff48a3aa734e259 Mon Sep 17 00:00:00 2001 From: John Garry Date: Mon, 4 Nov 2024 16:14:03 -0800 Subject: xfs: Support atomic write for statx Support providing info on atomic write unit min and max for an inode. For simplicity, currently we limit the min at the FS block size. As for max, we limit also at FS block size, as there is no current method to guarantee extent alignment or granularity for regular files. Reviewed-by: "Darrick J. Wong" Reviewed-by: Christoph Hellwig Signed-off-by: John Garry Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_buf.c | 7 +++++++ fs/xfs/xfs_buf.h | 4 ++++ fs/xfs/xfs_inode.h | 15 +++++++++++++++ fs/xfs/xfs_iops.c | 22 ++++++++++++++++++++++ 4 files changed, 48 insertions(+) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index aa4dbda7b536..e8196f5778e2 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -2115,6 +2115,13 @@ xfs_alloc_buftarg( btp->bt_daxdev = fs_dax_get_by_bdev(btp->bt_bdev, &btp->bt_dax_part_off, mp, ops); + if (bdev_can_atomic_write(btp->bt_bdev)) { + btp->bt_bdev_awu_min = bdev_atomic_write_unit_min_bytes( + btp->bt_bdev); + btp->bt_bdev_awu_max = bdev_atomic_write_unit_max_bytes( + btp->bt_bdev); + } + /* * When allocating the buftargs we have not yet read the super block and * thus don't know the file system sector size yet. diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index 209a389f2abc..3d56bc7a35cc 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -124,6 +124,10 @@ struct xfs_buftarg { struct percpu_counter bt_io_count; struct ratelimit_state bt_ioerror_rl; + /* Atomic write unit values */ + unsigned int bt_bdev_awu_min; + unsigned int bt_bdev_awu_max; + /* built-in cache, if we're not using the perag one */ struct xfs_buf_cache bt_cache[]; }; diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 97ed912306fd..73009a25a119 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -327,6 +327,21 @@ static inline bool xfs_inode_has_bigrtalloc(struct xfs_inode *ip) (XFS_IS_REALTIME_INODE(ip) ? \ (ip)->i_mount->m_rtdev_targp : (ip)->i_mount->m_ddev_targp) +static inline bool +xfs_inode_can_atomicwrite( + struct xfs_inode *ip) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + + if (mp->m_sb.sb_blocksize < target->bt_bdev_awu_min) + return false; + if (mp->m_sb.sb_blocksize > target->bt_bdev_awu_max) + return false; + + return true; +} + /* * In-core inode flags. */ diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index ee79cf161312..5cd804812efd 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -570,6 +570,20 @@ xfs_stat_blksize( return max_t(uint32_t, PAGE_SIZE, mp->m_sb.sb_blocksize); } +static void +xfs_get_atomic_write_attr( + struct xfs_inode *ip, + unsigned int *unit_min, + unsigned int *unit_max) +{ + if (!xfs_inode_can_atomicwrite(ip)) { + *unit_min = *unit_max = 0; + return; + } + + *unit_min = *unit_max = ip->i_mount->m_sb.sb_blocksize; +} + STATIC int xfs_vn_getattr( struct mnt_idmap *idmap, @@ -643,6 +657,14 @@ xfs_vn_getattr( stat->dio_mem_align = bdev_dma_alignment(bdev) + 1; stat->dio_offset_align = bdev_logical_block_size(bdev); } + if (request_mask & STATX_WRITE_ATOMIC) { + unsigned int unit_min, unit_max; + + xfs_get_atomic_write_attr(ip, &unit_min, + &unit_max); + generic_fill_statx_atomic_writes(stat, + unit_min, unit_max); + } fallthrough; default: stat->blksize = xfs_stat_blksize(ip); -- cgit v1.3.1 From f096207d327692a066954435dafb4bedbc031d9e Mon Sep 17 00:00:00 2001 From: John Garry Date: Mon, 4 Nov 2024 16:14:04 -0800 Subject: xfs: Validate atomic writes Validate that an atomic write adheres to length/offset rules. Currently we can only write a single FS block. For an IOCB with IOCB_ATOMIC set to get as far as xfs_file_write_iter(), FMODE_CAN_ATOMIC_WRITE will need to be set for the file; for this, ATOMICWRITES flags would also need to be set for the inode. Reviewed-by: Christoph Hellwig Reviewed-by: "Darrick J. Wong" Signed-off-by: John Garry Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_file.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 412b1d71b52b..44be10490342 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -822,6 +822,20 @@ xfs_file_write_iter( if (IS_DAX(inode)) return xfs_file_dax_write(iocb, from); + if (iocb->ki_flags & IOCB_ATOMIC) { + /* + * Currently only atomic writing of a single FS block is + * supported. It would be possible to atomic write smaller than + * a FS block, but there is no requirement to support this. + * Note that iomap also does not support this yet. + */ + if (ocount != ip->i_mount->m_sb.sb_blocksize) + return -EINVAL; + ret = generic_atomic_write_valid(iocb, from); + if (ret) + return ret; + } + if (iocb->ki_flags & IOCB_DIRECT) { /* * Allow a directio write to fall back to a buffered -- cgit v1.3.1 From 3af5298ce94bb672845adadf347874ba5bcfad2c Mon Sep 17 00:00:00 2001 From: John Garry Date: Mon, 4 Nov 2024 16:14:04 -0800 Subject: xfs: Support setting FMODE_CAN_ATOMIC_WRITE Set FMODE_CAN_ATOMIC_WRITE flag if we can atomic write for that inode. Reviewed-by: Christoph Hellwig Reviewed-by: "Darrick J. Wong" Signed-off-by: John Garry Signed-off-by: Darrick J. Wong Reviewed-by: Jan Kara Reviewed-by: John Garry Tested-by: Ojaswin Mujoo #On ppc64 --- fs/xfs/xfs_file.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 44be10490342..c94019b12537 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1223,6 +1223,8 @@ xfs_file_open( if (xfs_is_shutdown(XFS_M(inode->i_sb))) return -EIO; file->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT; + if (xfs_inode_can_atomicwrite(XFS_I(inode))) + file->f_mode |= FMODE_CAN_ATOMIC_WRITE; return generic_file_open(inode, file); } -- cgit v1.3.1