Hi Darrick, Do you have any comment on this?
-- Thanks, Ruan. > -----Original Message----- > From: Shiyang Ruan <[email protected]> > Subject: [PATCH v6.1 6/7] fs/xfs: Handle CoW for fsdax write() path > > 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
