Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On Mon, Jul 13, 2020 at 08:39:20AM -0700, Darrick J. Wong wrote: > -ENOTBLK is already being used as a "magic" return code that means > "retry this direct write as a buffered write". Shouldn't we use that > instead? > > -EREMCHG was a private hack we put in XFS for the one case where a > direct write had to be done through the page cache (non block-aligned > COW), but maybe it's time we put that to rest since the rest of the > world apparently thinks the magic fallback code is -ENOTBLK. Sure, I can switch the error code.
Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On Mon, Jul 13, 2020 at 12:55:09PM +0100, Matthew Wilcox wrote: > On Mon, Jul 13, 2020 at 09:46:33AM +0200, Christoph Hellwig wrote: > > Failing to invalid the page cache means data in incoherent, which is > > a very bad state for the system. Always fall back to buffered I/O > > through the page cache if we can't invalidate mappings. > > Is that the right approach though? I don't have a full picture in my head, > but wouldn't we be better off marking these pages as !Uptodate and doing > the direct I/O? Isn't that a problem if e.g. pages are mapped into userspace and mlocked?
Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On 2020/07/13 16:51, Christoph Hellwig wrote:
> Failing to invalid the page cache means data in incoherent, which is
s/in incoherent/is incoherent
> a very bad state for the system. Always fall back to buffered I/O
> through the page cache if we can't invalidate mappings.
>
> Signed-off-by: Christoph Hellwig
> ---
> fs/ext4/file.c | 2 ++
> fs/gfs2/file.c | 3 ++-
> fs/iomap/direct-io.c | 13 -
> fs/iomap/trace.h | 1 +
> fs/xfs/xfs_file.c| 4 ++--
> fs/zonefs/super.c| 7 +--
> 6 files changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 2a01e31a032c4c..0da6c2a2c32c1e 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -544,6 +544,8 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb,
> struct iov_iter *from)
> iomap_ops = &ext4_iomap_overwrite_ops;
> ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
> is_sync_kiocb(iocb) || unaligned_io || extend);
> + if (ret == -EREMCHG)
> + ret = 0;
>
> if (extend)
> ret = ext4_handle_inode_extension(inode, offset, ret, count);
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index fe305e4bfd3734..c7907d40c61d17 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -814,7 +814,8 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb,
> struct iov_iter *from)
>
> ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
> is_sync_kiocb(iocb));
> -
> + if (ret == -EREMCHG)
> + ret = 0;
> out:
> gfs2_glock_dq(&gh);
> out_uninit:
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 190967e87b69e4..62626235cdbe8d 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -10,6 +10,7 @@
> #include
> #include
> #include
> +#include "trace.h"
>
> #include "../internal.h"
>
> @@ -478,13 +479,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> if (iov_iter_rw(iter) == WRITE) {
> /*
>* Try to invalidate cache pages for the range we are writing.
> - * If this invalidation fails, tough, the write will still work,
> - * but racing two incompatible write paths is a pretty crazy
> - * thing to do, so we don't support it 100%.
> + * If this invalidation fails, let the caller fall back to
> + * buffered I/O.
>*/
> if (invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
> - end >> PAGE_SHIFT))
> - dio_warn_stale_pagecache(iocb->ki_filp);
> + end >> PAGE_SHIFT)) {
> + trace_iomap_dio_invalidate_fail(inode, pos, count);
> + ret = -EREMCHG;
I am wondering if it is OK to unconditionally always return -EREMCHG here.
Shouldn't this depend on the return code of invalidate_inode_pages2_range() ?
ret may be the value returned by mapping->a_ops->launder_page(page) instead of
-EBUSY that invalidate_inode_pages2_range() otherwise returns for a failed
invalidation. Isn't their any error condition that would be better served by not
forcing the fallback to buffered write ? E.g. -ENOMEM ?
> + goto out_free_dio;
> + }
>
> if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) {
> ret = sb_init_dio_done_wq(inode->i_sb);
> diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
> index 5693a39d52fb63..fdc7ae388476f5 100644
> --- a/fs/iomap/trace.h
> +++ b/fs/iomap/trace.h
> @@ -74,6 +74,7 @@ DEFINE_EVENT(iomap_range_class, name, \
> DEFINE_RANGE_EVENT(iomap_writepage);
> DEFINE_RANGE_EVENT(iomap_releasepage);
> DEFINE_RANGE_EVENT(iomap_invalidatepage);
> +DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail);
>
> #define IOMAP_TYPE_STRINGS \
> { IOMAP_HOLE, "HOLE" }, \
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 00db81eac80d6c..551cca39fa3ba6 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -553,8 +553,8 @@ xfs_file_dio_aio_write(
> xfs_iunlock(ip, iolock);
>
> /*
> - * No fallback to buffered IO on errors for XFS, direct IO will either
> - * complete fully or fail.
> + * No partial fallback to buffered IO on errors for XFS, direct IO will
> + * either complete fully or fail.
>*/
> ASSERT(ret < 0 || ret == count);
> return ret;
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 07bc42d62673ce..793850454b752f 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -786,8 +786,11 @@ static ssize_t zonefs_file_write_iter(struct kiocb
> *iocb, struct iov_iter *from)
> if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
> return -EFBIG;
>
> - if (iocb->ki_flags & IOCB_DIRECT)
> - return zonefs_file_dio_write(iocb, from);
> +
Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On Mon, Jul 13, 2020 at 09:46:33AM +0200, Christoph Hellwig wrote:
> Failing to invalid the page cache means data in incoherent, which is
> a very bad state for the system. Always fall back to buffered I/O
> through the page cache if we can't invalidate mappings.
>
> Signed-off-by: Christoph Hellwig
> ---
> fs/ext4/file.c | 2 ++
> fs/gfs2/file.c | 3 ++-
> fs/iomap/direct-io.c | 13 -
> fs/iomap/trace.h | 1 +
> fs/xfs/xfs_file.c| 4 ++--
> fs/zonefs/super.c| 7 +--
> 6 files changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 2a01e31a032c4c..0da6c2a2c32c1e 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -544,6 +544,8 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb,
> struct iov_iter *from)
> iomap_ops = &ext4_iomap_overwrite_ops;
> ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
> is_sync_kiocb(iocb) || unaligned_io || extend);
> + if (ret == -EREMCHG)
> + ret = 0;
>
> if (extend)
> ret = ext4_handle_inode_extension(inode, offset, ret, count);
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index fe305e4bfd3734..c7907d40c61d17 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -814,7 +814,8 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb,
> struct iov_iter *from)
>
> ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
> is_sync_kiocb(iocb));
> -
> + if (ret == -EREMCHG)
> + ret = 0;
> out:
> gfs2_glock_dq(&gh);
> out_uninit:
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 190967e87b69e4..62626235cdbe8d 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -10,6 +10,7 @@
> #include
> #include
> #include
> +#include "trace.h"
>
> #include "../internal.h"
>
> @@ -478,13 +479,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> if (iov_iter_rw(iter) == WRITE) {
> /*
>* Try to invalidate cache pages for the range we are writing.
> - * If this invalidation fails, tough, the write will still work,
> - * but racing two incompatible write paths is a pretty crazy
> - * thing to do, so we don't support it 100%.
> + * If this invalidation fails, let the caller fall back to
> + * buffered I/O.
>*/
> if (invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
> - end >> PAGE_SHIFT))
> - dio_warn_stale_pagecache(iocb->ki_filp);
> + end >> PAGE_SHIFT)) {
> + trace_iomap_dio_invalidate_fail(inode, pos, count);
> + ret = -EREMCHG;
-ENOTBLK is already being used as a "magic" return code that means
"retry this direct write as a buffered write". Shouldn't we use that
instead?
-EREMCHG was a private hack we put in XFS for the one case where a
direct write had to be done through the page cache (non block-aligned
COW), but maybe it's time we put that to rest since the rest of the
world apparently thinks the magic fallback code is -ENOTBLK.
--D
> + goto out_free_dio;
> + }
>
> if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) {
> ret = sb_init_dio_done_wq(inode->i_sb);
> diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
> index 5693a39d52fb63..fdc7ae388476f5 100644
> --- a/fs/iomap/trace.h
> +++ b/fs/iomap/trace.h
> @@ -74,6 +74,7 @@ DEFINE_EVENT(iomap_range_class, name, \
> DEFINE_RANGE_EVENT(iomap_writepage);
> DEFINE_RANGE_EVENT(iomap_releasepage);
> DEFINE_RANGE_EVENT(iomap_invalidatepage);
> +DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail);
>
> #define IOMAP_TYPE_STRINGS \
> { IOMAP_HOLE, "HOLE" }, \
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 00db81eac80d6c..551cca39fa3ba6 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -553,8 +553,8 @@ xfs_file_dio_aio_write(
> xfs_iunlock(ip, iolock);
>
> /*
> - * No fallback to buffered IO on errors for XFS, direct IO will either
> - * complete fully or fail.
> + * No partial fallback to buffered IO on errors for XFS, direct IO will
> + * either complete fully or fail.
>*/
> ASSERT(ret < 0 || ret == count);
> return ret;
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 07bc42d62673ce..793850454b752f 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -786,8 +786,11 @@ static ssize_t zonefs_file_write_iter(struct kiocb
> *iocb, struct iov_iter *from)
> if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
> return -EFBIG;
>
> - if (iocb->ki_flags & IOCB_DIRECT)
> - return zonefs_file_dio_write(iocb, from);
> + if (iocb->ki_flags & IOCB_DIRECT) {
Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On Mon, Jul 13, 2020 at 07:20:50AM -0500, Goldwyn Rodrigues wrote: > On 9:46 13/07, Christoph Hellwig wrote: > > Failing to invalid the page cache means data in incoherent, which is > > a very bad state for the system. Always fall back to buffered I/O > > through the page cache if we can't invalidate mappings. > > > > Signed-off-by: Christoph Hellwig > > Thanks. This will help btrfs. The current next tree contains the iomap > changes I recomended and would need to be reverted in order to > incorporate this. Once this is in the next tree I will (re)format the > btrfs iomap dio patches. Patches in next don't need to be reverted, if you put together a branch with any iomap or other prep patches + btrfs iomap-dio I'll replace it in the for-next snapshot I push.
Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On 9:46 13/07, Christoph Hellwig wrote:
> Failing to invalid the page cache means data in incoherent, which is
> a very bad state for the system. Always fall back to buffered I/O
> through the page cache if we can't invalidate mappings.
>
> Signed-off-by: Christoph Hellwig
Thanks. This will help btrfs. The current next tree contains the iomap
changes I recomended and would need to be reverted in order to
incorporate this. Once this is in the next tree I will (re)format the
btrfs iomap dio patches.
Reviewed-by: Goldwyn Rodrigues
> ---
> fs/ext4/file.c | 2 ++
> fs/gfs2/file.c | 3 ++-
> fs/iomap/direct-io.c | 13 -
> fs/iomap/trace.h | 1 +
> fs/xfs/xfs_file.c| 4 ++--
> fs/zonefs/super.c| 7 +--
> 6 files changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 2a01e31a032c4c..0da6c2a2c32c1e 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -544,6 +544,8 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb,
> struct iov_iter *from)
> iomap_ops = &ext4_iomap_overwrite_ops;
> ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
> is_sync_kiocb(iocb) || unaligned_io || extend);
> + if (ret == -EREMCHG)
> + ret = 0;
>
> if (extend)
> ret = ext4_handle_inode_extension(inode, offset, ret, count);
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index fe305e4bfd3734..c7907d40c61d17 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -814,7 +814,8 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb,
> struct iov_iter *from)
>
> ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
> is_sync_kiocb(iocb));
> -
> + if (ret == -EREMCHG)
> + ret = 0;
> out:
> gfs2_glock_dq(&gh);
> out_uninit:
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 190967e87b69e4..62626235cdbe8d 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -10,6 +10,7 @@
> #include
> #include
> #include
> +#include "trace.h"
>
> #include "../internal.h"
>
> @@ -478,13 +479,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> if (iov_iter_rw(iter) == WRITE) {
> /*
>* Try to invalidate cache pages for the range we are writing.
> - * If this invalidation fails, tough, the write will still work,
> - * but racing two incompatible write paths is a pretty crazy
> - * thing to do, so we don't support it 100%.
> + * If this invalidation fails, let the caller fall back to
> + * buffered I/O.
>*/
> if (invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
> - end >> PAGE_SHIFT))
> - dio_warn_stale_pagecache(iocb->ki_filp);
> + end >> PAGE_SHIFT)) {
> + trace_iomap_dio_invalidate_fail(inode, pos, count);
> + ret = -EREMCHG;
> + goto out_free_dio;
> + }
>
> if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) {
> ret = sb_init_dio_done_wq(inode->i_sb);
> diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
> index 5693a39d52fb63..fdc7ae388476f5 100644
> --- a/fs/iomap/trace.h
> +++ b/fs/iomap/trace.h
> @@ -74,6 +74,7 @@ DEFINE_EVENT(iomap_range_class, name, \
> DEFINE_RANGE_EVENT(iomap_writepage);
> DEFINE_RANGE_EVENT(iomap_releasepage);
> DEFINE_RANGE_EVENT(iomap_invalidatepage);
> +DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail);
>
> #define IOMAP_TYPE_STRINGS \
> { IOMAP_HOLE, "HOLE" }, \
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 00db81eac80d6c..551cca39fa3ba6 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -553,8 +553,8 @@ xfs_file_dio_aio_write(
> xfs_iunlock(ip, iolock);
>
> /*
> - * No fallback to buffered IO on errors for XFS, direct IO will either
> - * complete fully or fail.
> + * No partial fallback to buffered IO on errors for XFS, direct IO will
> + * either complete fully or fail.
>*/
> ASSERT(ret < 0 || ret == count);
> return ret;
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 07bc42d62673ce..793850454b752f 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -786,8 +786,11 @@ static ssize_t zonefs_file_write_iter(struct kiocb
> *iocb, struct iov_iter *from)
> if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
> return -EFBIG;
>
> - if (iocb->ki_flags & IOCB_DIRECT)
> - return zonefs_file_dio_write(iocb, from);
> + if (iocb->ki_flags & IOCB_DIRECT) {
> + ret = zonefs_file_dio_write(iocb, from);
> + if (ret != -EREMCHG)
> + return ret;
> + }
>
> return zonefs_file_buffered_wri
Re: [Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
On Mon, Jul 13, 2020 at 09:46:33AM +0200, Christoph Hellwig wrote: > Failing to invalid the page cache means data in incoherent, which is > a very bad state for the system. Always fall back to buffered I/O > through the page cache if we can't invalidate mappings. Is that the right approach though? I don't have a full picture in my head, but wouldn't we be better off marking these pages as !Uptodate and doing the direct I/O?
[Cluster-devel] [PATCH 2/2] iomap: fall back to buffered writes for invalidation failures
Failing to invalid the page cache means data in incoherent, which is
a very bad state for the system. Always fall back to buffered I/O
through the page cache if we can't invalidate mappings.
Signed-off-by: Christoph Hellwig
---
fs/ext4/file.c | 2 ++
fs/gfs2/file.c | 3 ++-
fs/iomap/direct-io.c | 13 -
fs/iomap/trace.h | 1 +
fs/xfs/xfs_file.c| 4 ++--
fs/zonefs/super.c| 7 +--
6 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 2a01e31a032c4c..0da6c2a2c32c1e 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -544,6 +544,8 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb,
struct iov_iter *from)
iomap_ops = &ext4_iomap_overwrite_ops;
ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
is_sync_kiocb(iocb) || unaligned_io || extend);
+ if (ret == -EREMCHG)
+ ret = 0;
if (extend)
ret = ext4_handle_inode_extension(inode, offset, ret, count);
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index fe305e4bfd3734..c7907d40c61d17 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -814,7 +814,8 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb,
struct iov_iter *from)
ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
is_sync_kiocb(iocb));
-
+ if (ret == -EREMCHG)
+ ret = 0;
out:
gfs2_glock_dq(&gh);
out_uninit:
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 190967e87b69e4..62626235cdbe8d 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -10,6 +10,7 @@
#include
#include
#include
+#include "trace.h"
#include "../internal.h"
@@ -478,13 +479,15 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
if (iov_iter_rw(iter) == WRITE) {
/*
* Try to invalidate cache pages for the range we are writing.
-* If this invalidation fails, tough, the write will still work,
-* but racing two incompatible write paths is a pretty crazy
-* thing to do, so we don't support it 100%.
+* If this invalidation fails, let the caller fall back to
+* buffered I/O.
*/
if (invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
- end >> PAGE_SHIFT))
- dio_warn_stale_pagecache(iocb->ki_filp);
+ end >> PAGE_SHIFT)) {
+ trace_iomap_dio_invalidate_fail(inode, pos, count);
+ ret = -EREMCHG;
+ goto out_free_dio;
+ }
if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) {
ret = sb_init_dio_done_wq(inode->i_sb);
diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
index 5693a39d52fb63..fdc7ae388476f5 100644
--- a/fs/iomap/trace.h
+++ b/fs/iomap/trace.h
@@ -74,6 +74,7 @@ DEFINE_EVENT(iomap_range_class, name, \
DEFINE_RANGE_EVENT(iomap_writepage);
DEFINE_RANGE_EVENT(iomap_releasepage);
DEFINE_RANGE_EVENT(iomap_invalidatepage);
+DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail);
#define IOMAP_TYPE_STRINGS \
{ IOMAP_HOLE, "HOLE" }, \
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 00db81eac80d6c..551cca39fa3ba6 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -553,8 +553,8 @@ xfs_file_dio_aio_write(
xfs_iunlock(ip, iolock);
/*
-* No fallback to buffered IO on errors for XFS, direct IO will either
-* complete fully or fail.
+* No partial fallback to buffered IO on errors for XFS, direct IO will
+* either complete fully or fail.
*/
ASSERT(ret < 0 || ret == count);
return ret;
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 07bc42d62673ce..793850454b752f 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -786,8 +786,11 @@ static ssize_t zonefs_file_write_iter(struct kiocb *iocb,
struct iov_iter *from)
if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
return -EFBIG;
- if (iocb->ki_flags & IOCB_DIRECT)
- return zonefs_file_dio_write(iocb, from);
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ ret = zonefs_file_dio_write(iocb, from);
+ if (ret != -EREMCHG)
+ return ret;
+ }
return zonefs_file_buffered_write(iocb, from);
}
--
2.26.2
