[RFC PATCH v2 07/19] fs/xfs: Teach xfs to use new dax_layout_busy_page()

ira.weiny
2019-08-09T22:58:58Z

From: Ira Weiny <ira.weiny@intel.com>

dax_layout_busy_page() can now operate on a sub-range of the
address_space provided.

Have xfs specify the sub range to dax_layout_busy_page()

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
fs/xfs/xfs_file.c | 19 +++++++++++++------
fs/xfs/xfs_inode.h | 5 +++--
fs/xfs/xfs_ioctl.c | 15 ++++++++++++---
fs/xfs/xfs_iops.c | 14 ++++++++++----
4 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 8f8d478f9ec6..447571e3cb02 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -295,7 +295,11 @@ xfs_file_aio_write_checks(
if (error <= 0)
return error;

- error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
+ /*
+ * BREAK_WRITE ignores offset/len tuple just specify the whole file
+ * (0 - ULONG_MAX to be safe.
+ */
+ error = xfs_break_layouts(inode, iolock, 0, ULONG_MAX, BREAK_WRITE);
if (error)
return error;

@@ -734,14 +738,15 @@ xfs_wait_dax_page(
static int
xfs_break_dax_layouts(
struct inode *inode,
- bool *retry)
+ bool *retry,
+ loff_t off,
+ loff_t len)
{
struct page *page;

ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL));

- /* We default to the "whole file" */
- page = dax_layout_busy_page(inode->i_mapping, 0, ULONG_MAX);
+ page = dax_layout_busy_page(inode->i_mapping, off, len);
if (!page)
return 0;

@@ -755,6 +760,8 @@ int
xfs_break_layouts(
struct inode *inode,
uint *iolock,
+ loff_t off,
+ loff_t len,
enum layout_break_reason reason)
{
bool retry;
@@ -766,7 +773,7 @@ xfs_break_layouts(
retry = false;
switch (reason) {
case BREAK_UNMAP:
- error = xfs_break_dax_layouts(inode, &retry);
+ error = xfs_break_dax_layouts(inode, &retry, off, len);
if (error || retry)
break;
/* fall through */
@@ -808,7 +815,7 @@ xfs_file_fallocate(
return -EOPNOTSUPP;

xfs_ilock(ip, iolock);
- error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
+ error = xfs_break_layouts(inode, &iolock, offset, len, BREAK_UNMAP);
if (error)
goto out_unlock;

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 558173f95a03..1b0948f5267c 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -475,8 +475,9 @@ enum xfs_prealloc_flags {

int xfs_update_prealloc_flags(struct xfs_inode *ip,
enum xfs_prealloc_flags flags);
-int xfs_break_layouts(struct inode *inode, uint *iolock,
- enum layout_break_reason reason);
+int xfs_break_layouts(struct inode *inode, uint *iolock,
+ loff_t off, loff_t len,
+ enum layout_break_reason reason);

/* from xfs_iops.c */
extern void xfs_setup_inode(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 6f7848cd5527..3897b88080bd 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -597,6 +597,7 @@ xfs_ioc_space(
enum xfs_prealloc_flags flags = 0;
uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
int error;
+ loff_t break_length;

if (inode->i_flags & (S_IMMUTABLE|S_APPEND))
return -EPERM;
@@ -617,9 +618,6 @@ xfs_ioc_space(
return error;

xfs_ilock(ip, iolock);
- error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
- if (error)
- goto out_unlock;

switch (bf->l_whence) {
case 0: /*SEEK_SET*/
@@ -665,6 +663,17 @@ xfs_ioc_space(
goto out_unlock;
}

+ /* break layout for the whole file if len ends up 0 */
+ if (bf->l_len == 0)
+ break_length = ULONG_MAX;
+ else
+ break_length = bf->l_len;
+
+ error = xfs_break_layouts(inode, &iolock, bf->l_start, break_length,
+ BREAK_UNMAP);
+ if (error)
+ goto out_unlock;
+
switch (cmd) {
case XFS_IOC_ZERO_RANGE:
flags |= XFS_PREALLOC_SET;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index ff3c1fae5357..f0de5486f6c1 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1042,10 +1042,16 @@ xfs_vn_setattr(
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;

- error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
- if (error) {
- xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
- return error;
+ if (iattr->ia_size < inode->i_size) {
+ loff_t off = iattr->ia_size;
+ loff_t len = inode->i_size - iattr->ia_size;
+
+ error = xfs_break_layouts(inode, &iolock, off, len,
+ BREAK_UNMAP);
+ if (error) {
+ xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
+ return error;
+ }
}

error = xfs_vn_setattr_size(dentry, iattr);
--
2.20.1