Hi Darrick, Since other patches looks good, I post this RFC patch singly to hot-fix the problem in xfs_dax_write_iomap_ops->iomap_end() of v6 that the error code was ingored. I will split this in two patches(changes in iomap and xfs respectively) in next formal version if it looks ok.
==== Introduce a new interface called "iomap_post_actor()" in iomap_ops. And call it between ->actor() and ->iomap_end(). It is mean to handle the error code returned from ->actor(). In this patchset, it is used to remap or cancel the CoW extents according to the error code. Signed-off-by: Shiyang Ruan <[email protected]> --- fs/dax.c | 27 ++++++++++++++++++--------- fs/iomap/apply.c | 4 ++++ fs/xfs/xfs_bmap_util.c | 3 +-- fs/xfs/xfs_file.c | 5 +++-- fs/xfs/xfs_iomap.c | 33 ++++++++++++++++++++++++++++++++- fs/xfs/xfs_iomap.h | 24 ++++++++++++++++++++++++ fs/xfs/xfs_iops.c | 7 +++---- fs/xfs/xfs_reflink.c | 3 +-- include/linux/iomap.h | 8 ++++++++ 9 files changed, 94 insertions(+), 20 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 93f16210847b..0740c2610b6f 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1537,7 +1537,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, struct iomap iomap = { .type = IOMAP_HOLE }; struct iomap srcmap = { .type = IOMAP_HOLE }; unsigned flags = IOMAP_FAULT; - int error; + int error, copied = PAGE_SIZE; bool write = vmf->flags & FAULT_FLAG_WRITE; vm_fault_t ret = 0, major = 0; void *entry; @@ -1598,7 +1598,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, ret = dax_fault_actor(vmf, pfnp, &xas, &entry, false, flags, &iomap, &srcmap); if (ret == VM_FAULT_SIGBUS) - goto finish_iomap; + goto finish_iomap_actor; /* read/write MAPPED, CoW UNWRITTEN */ if (iomap.flags & IOMAP_F_NEW) { @@ -1607,10 +1607,16 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, major = VM_FAULT_MAJOR; } + finish_iomap_actor: + if (ops->iomap_post_actor) { + if (ret & VM_FAULT_ERROR) + copied = 0; + ops->iomap_post_actor(inode, pos, PMD_SIZE, copied, flags, + &iomap, &srcmap); + } + finish_iomap: if (ops->iomap_end) { - int copied = PAGE_SIZE; - if (ret & VM_FAULT_ERROR) copied = 0; /* @@ -1677,7 +1683,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, pgoff_t max_pgoff; void *entry; loff_t pos; - int error; + int error, copied = PMD_SIZE; /* * Check whether offset isn't beyond end of file now. Caller is @@ -1736,12 +1742,15 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, ret = dax_fault_actor(vmf, pfnp, &xas, &entry, true, flags, &iomap, &srcmap); + if (ret == VM_FAULT_FALLBACK) + copied = 0; + if (ops->iomap_post_actor) { + ops->iomap_post_actor(inode, pos, PMD_SIZE, copied, flags, + &iomap, &srcmap); + } + finish_iomap: if (ops->iomap_end) { - int copied = PMD_SIZE; - - if (ret == VM_FAULT_FALLBACK) - copied = 0; /* * The fault is done by now and there's no way back (other * thread may be already happily using PMD we have installed). diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c index 0493da5286ad..26a54ded184f 100644 --- a/fs/iomap/apply.c +++ b/fs/iomap/apply.c @@ -84,6 +84,10 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, written = actor(inode, pos, length, data, &iomap, srcmap.type != IOMAP_HOLE ? &srcmap : &iomap); + if (ops->iomap_post_actor) { + written = ops->iomap_post_actor(inode, pos, length, written, + flags, &iomap, &srcmap); + } out: /* * Now the data has been copied, commit the range we've copied. This diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index a5e9d7d34023..2a36dc93ff27 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -965,8 +965,7 @@ xfs_free_file_space( return 0; if (offset + len > XFS_ISIZE(ip)) len = XFS_ISIZE(ip) - offset; - error = iomap_zero_range(VFS_I(ip), offset, len, NULL, - &xfs_buffered_write_iomap_ops); + error = xfs_iomap_zero_range(ip, offset, len, NULL); if (error) return error; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 396ef36dcd0a..89406ec6741b 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -684,11 +684,12 @@ xfs_file_dax_write( pos = iocb->ki_pos; trace_xfs_file_dax_write(iocb, from); - ret = dax_iomap_rw(iocb, from, &xfs_direct_write_iomap_ops); + ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops); if (ret > 0 && iocb->ki_pos > i_size_read(inode)) { i_size_write(inode, iocb->ki_pos); error = xfs_setfilesize(ip, pos, ret); } + out: if (iolock) xfs_iunlock(ip, iolock); @@ -1309,7 +1310,7 @@ __xfs_filemap_fault( ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, (write_fault && !vmf->cow_page) ? - &xfs_direct_write_iomap_ops : + &xfs_dax_write_iomap_ops : &xfs_read_iomap_ops); if (ret & VM_FAULT_NEEDDSYNC) ret = dax_finish_sync_fault(vmf, pe_size, pfn); diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index d154f42e2dc6..2f322e2f8544 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -761,7 +761,8 @@ xfs_direct_write_iomap_begin( /* may drop and re-acquire the ilock */ error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared, - &lockmode, flags & IOMAP_DIRECT); + &lockmode, + (flags & IOMAP_DIRECT) || IS_DAX(inode)); if (error) goto out_unlock; if (shared) @@ -854,6 +855,36 @@ const struct iomap_ops xfs_direct_write_iomap_ops = { .iomap_begin = xfs_direct_write_iomap_begin, }; +static int +xfs_dax_write_iomap_post_actor( + struct inode *inode, + loff_t pos, + loff_t length, + ssize_t written, + unsigned int flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + int error = 0; + struct xfs_inode *ip = XFS_I(inode); + bool cow = xfs_is_cow_inode(ip); + + if (written <= 0) { + if (cow) + xfs_reflink_cancel_cow_range(ip, pos, length, true); + return written; + } + + if (cow) + error = xfs_reflink_end_cow(ip, pos, written); + return error ?: written; +} + +const struct iomap_ops xfs_dax_write_iomap_ops = { + .iomap_begin = xfs_direct_write_iomap_begin, + .iomap_post_actor = xfs_dax_write_iomap_post_actor, +}; + static int xfs_buffered_write_iomap_begin( struct inode *inode, diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h index 7d3703556d0e..fbacf638ab21 100644 --- a/fs/xfs/xfs_iomap.h +++ b/fs/xfs/xfs_iomap.h @@ -42,8 +42,32 @@ xfs_aligned_fsb_count( extern const struct iomap_ops xfs_buffered_write_iomap_ops; extern const struct iomap_ops xfs_direct_write_iomap_ops; +extern const struct iomap_ops xfs_dax_write_iomap_ops; extern const struct iomap_ops xfs_read_iomap_ops; extern const struct iomap_ops xfs_seek_iomap_ops; extern const struct iomap_ops xfs_xattr_iomap_ops; +static inline int +xfs_iomap_zero_range( + struct xfs_inode *ip, + loff_t offset, + loff_t len, + bool *did_zero) +{ + return iomap_zero_range(VFS_I(ip), offset, len, did_zero, + IS_DAX(VFS_I(ip)) ? &xfs_dax_write_iomap_ops + : &xfs_buffered_write_iomap_ops); +} + +static inline int +xfs_iomap_truncate_page( + struct xfs_inode *ip, + loff_t pos, + bool *did_zero) +{ + return iomap_truncate_page(VFS_I(ip), pos, did_zero, + IS_DAX(VFS_I(ip)) ? &xfs_dax_write_iomap_ops + : &xfs_buffered_write_iomap_ops); +} + #endif /* __XFS_IOMAP_H__*/ diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index dfe24b7f26e5..6d936c3e1a6e 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -911,8 +911,8 @@ xfs_setattr_size( */ if (newsize > oldsize) { trace_xfs_zero_eof(ip, oldsize, newsize - oldsize); - error = iomap_zero_range(inode, oldsize, newsize - oldsize, - &did_zeroing, &xfs_buffered_write_iomap_ops); + error = xfs_iomap_zero_range(ip, oldsize, newsize - oldsize, + &did_zeroing); } else { /* * iomap won't detect a dirty page over an unwritten block (or a @@ -924,8 +924,7 @@ xfs_setattr_size( newsize); if (error) return error; - error = iomap_truncate_page(inode, newsize, &did_zeroing, - &xfs_buffered_write_iomap_ops); + error = xfs_iomap_truncate_page(ip, newsize, &did_zeroing); } if (error) diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index d25434f93235..9a780948dbd0 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1266,8 +1266,7 @@ xfs_reflink_zero_posteof( return 0; trace_xfs_zero_eof(ip, isize, pos - isize); - return iomap_zero_range(VFS_I(ip), isize, pos - isize, NULL, - &xfs_buffered_write_iomap_ops); + return xfs_iomap_zero_range(ip, isize, pos - isize, NULL); } /* diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 95562f863ad0..58f2e1c78018 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -135,6 +135,14 @@ struct iomap_ops { unsigned flags, struct iomap *iomap, struct iomap *srcmap); + /* + * Handle the error code from actor(). Do the finishing jobs for extra + * operations, such as CoW, according to whether written is negative. + */ + int (*iomap_post_actor)(struct inode *inode, loff_t pos, loff_t length, + ssize_t written, unsigned flags, struct iomap *iomap, + struct iomap *srcmap); + /* * Commit and/or unreserve space previous allocated using iomap_begin. * Written indicates the length of the successful write operation which -- 2.31.1
