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Merge patch series "add STATX_DIO_READ_ALIGN v3"

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Christoph Hellwig <hch@lst.de> says:

File systems that write out of place usually require different alignment
for direct I/O writes than what they can do for reads.  This series tries
to address this by adding yet another statx field.

* patches from https://lore.kernel.org/r/20250109083109.1441561-1-hch@lst.de:
  xfs: report larger dio alignment for COW inodes
  xfs: report the correct read/write dio alignment for reflinked inodes
  xfs: cleanup xfs_vn_getattr
  fs: add STATX_DIO_READ_ALIGN
  fs: reformat the statx definition

Link: https://lore.kernel.org/r/20250109083109.1441561-1-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner
2025-01-09 16:23:26 +01:00
parent 40384c840e 468210ec76
commit cf40ebb2ed
5 changed files with 125 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/stat.c
+1
View File
@@ -725,6 +725,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
tmp.stx_mnt_id = stat->mnt_id;
tmp.stx_dio_mem_align = stat->dio_mem_align;
tmp.stx_dio_offset_align = stat->dio_offset_align;
tmp.stx_dio_read_offset_align = stat->dio_read_offset_align;
tmp.stx_subvol = stat->subvol;
tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
fs/xfs/xfs_ioctl.c
+10 -1
View File
@@ -1204,7 +1204,16 @@ xfs_file_ioctl(
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
struct dioattr da;
da.d_mem = da.d_miniosz = target->bt_logical_sectorsize;
da.d_mem = target->bt_logical_sectorsize;
/*
* See xfs_report_dioalign() for an explanation about why this
* reports a value larger than the sector size for COW inodes.
*/
if (xfs_is_cow_inode(ip))
da.d_miniosz = xfs_inode_alloc_unitsize(ip);
else
da.d_miniosz = target->bt_logical_sectorsize;
da.d_maxiosz = INT_MAX & ~(da.d_miniosz - 1);
if (copy_to_user(arg, &da, sizeof(da)))
fs/xfs/xfs_iops.c
+38 -24
View File
@@ -573,17 +573,43 @@ xfs_stat_blksize(
}
static void
xfs_get_atomic_write_attr(
xfs_report_dioalign(
struct xfs_inode *ip,
unsigned int *unit_min,
unsigned int *unit_max)
struct kstat *stat)
{
if (!xfs_inode_can_atomicwrite(ip)) {
*unit_min = *unit_max = 0;
return;
}
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
struct block_device *bdev = target->bt_bdev;
*unit_min = *unit_max = ip->i_mount->m_sb.sb_blocksize;
stat->result_mask |= STATX_DIOALIGN | STATX_DIO_READ_ALIGN;
stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
/*
* For COW inodes, we can only perform out of place writes of entire
* allocation units (blocks or RT extents).
* For writes smaller than the allocation unit, we must fall back to
* buffered I/O to perform read-modify-write cycles. At best this is
* highly inefficient; at worst it leads to page cache invalidation
* races. Tell applications to avoid this by reporting the larger write
* alignment in dio_offset_align, and the smaller read alignment in
* dio_read_offset_align.
*/
stat->dio_read_offset_align = bdev_logical_block_size(bdev);
if (xfs_is_cow_inode(ip))
stat->dio_offset_align = xfs_inode_alloc_unitsize(ip);
else
stat->dio_offset_align = stat->dio_read_offset_align;
}
static void
xfs_report_atomic_write(
struct xfs_inode *ip,
struct kstat *stat)
{
unsigned int unit_min = 0, unit_max = 0;
if (xfs_inode_can_atomicwrite(ip))
unit_min = unit_max = ip->i_mount->m_sb.sb_blocksize;
generic_fill_statx_atomic_writes(stat, unit_min, unit_max);
}
STATIC int
@@ -647,22 +673,10 @@ xfs_vn_getattr(
stat->rdev = inode->i_rdev;
break;
case S_IFREG:
if (request_mask & STATX_DIOALIGN) {
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
struct block_device *bdev = target->bt_bdev;
stat->result_mask |= STATX_DIOALIGN;
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);
}
if (request_mask & (STATX_DIOALIGN | STATX_DIO_READ_ALIGN))
xfs_report_dioalign(ip, stat);
if (request_mask & STATX_WRITE_ATOMIC)
xfs_report_atomic_write(ip, stat);
fallthrough;
default:
stat->blksize = xfs_stat_blksize(ip);
include/linux/stat.h
+1
View File
@@ -52,6 +52,7 @@ struct kstat {
u64 mnt_id;
u32 dio_mem_align;
u32 dio_offset_align;
u32 dio_read_offset_align;
u64 change_cookie;
u64 subvol;
u32 atomic_write_unit_min;
include/uapi/linux/stat.h
+75 -24
View File
@@ -98,43 +98,93 @@ struct statx_timestamp {
*/
struct statx {
/* 0x00 */
__u32 stx_mask; /* What results were written [uncond] */
__u32 stx_blksize; /* Preferred general I/O size [uncond] */
__u64 stx_attributes; /* Flags conveying information about the file [uncond] */
/* What results were written [uncond] */
__u32 stx_mask;
/* Preferred general I/O size [uncond] */
__u32 stx_blksize;
/* Flags conveying information about the file [uncond] */
__u64 stx_attributes;
/* 0x10 */
__u32 stx_nlink; /* Number of hard links */
__u32 stx_uid; /* User ID of owner */
__u32 stx_gid; /* Group ID of owner */
__u16 stx_mode; /* File mode */
/* Number of hard links */
__u32 stx_nlink;
/* User ID of owner */
__u32 stx_uid;
/* Group ID of owner */
__u32 stx_gid;
/* File mode */
__u16 stx_mode;
__u16 __spare0[1];
/* 0x20 */
__u64 stx_ino; /* Inode number */
__u64 stx_size; /* File size */
__u64 stx_blocks; /* Number of 512-byte blocks allocated */
__u64 stx_attributes_mask; /* Mask to show what's supported in stx_attributes */
/* Inode number */
__u64 stx_ino;
/* File size */
__u64 stx_size;
/* Number of 512-byte blocks allocated */
__u64 stx_blocks;
/* Mask to show what's supported in stx_attributes */
__u64 stx_attributes_mask;
/* 0x40 */
struct statx_timestamp stx_atime; /* Last access time */
struct statx_timestamp stx_btime; /* File creation time */
struct statx_timestamp stx_ctime; /* Last attribute change time */
struct statx_timestamp stx_mtime; /* Last data modification time */
/* Last access time */
struct statx_timestamp stx_atime;
/* File creation time */
struct statx_timestamp stx_btime;
/* Last attribute change time */
struct statx_timestamp stx_ctime;
/* Last data modification time */
struct statx_timestamp stx_mtime;
/* 0x80 */
__u32 stx_rdev_major; /* Device ID of special file [if bdev/cdev] */
/* Device ID of special file [if bdev/cdev] */
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major; /* ID of device containing file [uncond] */
/* ID of device containing file [uncond] */
__u32 stx_dev_major;
__u32 stx_dev_minor;
/* 0x90 */
__u64 stx_mnt_id;
__u32 stx_dio_mem_align; /* Memory buffer alignment for direct I/O */
__u32 stx_dio_offset_align; /* File offset alignment for direct I/O */
/* Memory buffer alignment for direct I/O */
__u32 stx_dio_mem_align;
/* File offset alignment for direct I/O */
__u32 stx_dio_offset_align;
/* 0xa0 */
__u64 stx_subvol; /* Subvolume identifier */
__u32 stx_atomic_write_unit_min; /* Min atomic write unit in bytes */
__u32 stx_atomic_write_unit_max; /* Max atomic write unit in bytes */
/* Subvolume identifier */
__u64 stx_subvol;
/* Min atomic write unit in bytes */
__u32 stx_atomic_write_unit_min;
/* Max atomic write unit in bytes */
__u32 stx_atomic_write_unit_max;
/* 0xb0 */
__u32 stx_atomic_write_segments_max; /* Max atomic write segment count */
__u32 __spare1[1];
/* Max atomic write segment count */
__u32 stx_atomic_write_segments_max;
/* File offset alignment for direct I/O reads */
__u32 stx_dio_read_offset_align;
/* 0xb8 */
__u64 __spare3[9]; /* Spare space for future expansion */
/* 0x100 */
};
@@ -164,6 +214,7 @@ struct statx {
#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */
#define STATX_SUBVOL 0x00008000U /* Want/got stx_subvol */
#define STATX_WRITE_ATOMIC 0x00010000U /* Want/got atomic_write_* fields */
#define STATX_DIO_READ_ALIGN 0x00020000U /* Want/got dio read alignment info */
#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */