Modify the writepage handler to find and convert pending delalloc
extents to real allocations.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/xfs_aops.c | 63 +++++++++++++++++++++++++++++++++++---------
fs/xfs/xfs_aops.h | 10 +++++++
fs/xfs/xfs_reflink.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_reflink.h | 3 ++
4 files changed, 135 insertions(+), 13 deletions(-)
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 13629d2..7179b25 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -285,7 +285,8 @@ xfs_map_blocks(
loff_t offset,
struct xfs_bmbt_irec *imap,
int type,
- int nonblocking)
+ int nonblocking,
+ bool is_cow)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
@@ -294,10 +295,15 @@ xfs_map_blocks(
int error = 0;
int bmapi_flags = XFS_BMAPI_ENTIRE;
int nimaps = 1;
+ int whichfork;
+ bool need_alloc;
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
+ whichfork = (is_cow ? XFS_COW_FORK : XFS_DATA_FORK);
+ need_alloc = (type == XFS_IO_DELALLOC);
+
if (type == XFS_IO_UNWRITTEN)
bmapi_flags |= XFS_BMAPI_IGSTATE;
@@ -315,16 +321,21 @@ xfs_map_blocks(
count = mp->m_super->s_maxbytes - offset;
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
- error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
- imap, &nimaps, bmapi_flags);
+
+ if (is_cow)
+ error = xfs_reflink_find_cow_mapping(ip, offset, imap,
+ &need_alloc);
+ else
+ error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
+ imap, &nimaps, bmapi_flags);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (error)
return error;
- if (type == XFS_IO_DELALLOC &&
+ if (need_alloc &&
(!nimaps || isnullstartblock(imap->br_startblock))) {
- error = xfs_iomap_write_allocate(ip, XFS_DATA_FORK, offset,
+ error = xfs_iomap_write_allocate(ip, whichfork, offset,
imap);
if (!error)
trace_xfs_map_blocks_alloc(ip, offset, count, type,
@@ -575,7 +586,8 @@ xfs_add_to_ioend(
xfs_off_t offset,
unsigned int type,
xfs_ioend_t **result,
- int need_ioend)
+ int need_ioend,
+ bool is_cow)
{
xfs_ioend_t *ioend = *result;
@@ -593,6 +605,8 @@ xfs_add_to_ioend(
ioend->io_buffer_tail->b_private = bh;
ioend->io_buffer_tail = bh;
}
+ if (is_cow)
+ ioend->io_flags |= XFS_IOEND_COW;
bh->b_private = NULL;
ioend->io_size += bh->b_size;
@@ -703,6 +717,8 @@ xfs_convert_page(
int len, page_dirty;
int count = 0, done = 0, uptodate = 1;
xfs_off_t offset = page_offset(page);
+ bool is_cow;
+ struct xfs_inode *ip = XFS_I(inode);
if (page->index != tindex)
goto fail;
@@ -786,6 +802,15 @@ xfs_convert_page(
else
type = XFS_IO_OVERWRITE;
+ /* Figure out if CoW is pending for the other pages. */
+ is_cow = false;
+ if (type == XFS_IO_OVERWRITE &&
+ xfs_sb_version_hasreflink(&ip->i_mount->m_sb)) {
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ is_cow = xfs_reflink_is_cow_pending(ip, offset);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ }
+
/*
* imap should always be valid because of the above
* partial page end_offset check on the imap.
@@ -793,10 +818,10 @@ xfs_convert_page(
ASSERT(xfs_imap_valid(inode, imap, offset));
lock_buffer(bh);
- if (type != XFS_IO_OVERWRITE)
+ if (type != XFS_IO_OVERWRITE || is_cow)
xfs_map_at_offset(inode, bh, imap, offset);
xfs_add_to_ioend(inode, bh, offset, type,
- ioendp, done);
+ ioendp, done, is_cow);
page_dirty--;
count++;
@@ -959,6 +984,8 @@ xfs_vm_writepage(
int err, imap_valid = 0, uptodate = 1;
int count = 0;
int nonblocking = 0;
+ struct xfs_inode *ip = XFS_I(inode);
+ bool was_cow, is_cow;
trace_xfs_writepage(inode, page, 0, 0);
@@ -1057,6 +1084,7 @@ xfs_vm_writepage(
bh = head = page_buffers(page);
offset = page_offset(page);
type = XFS_IO_OVERWRITE;
+ was_cow = false;
if (wbc->sync_mode == WB_SYNC_NONE)
nonblocking = 1;
@@ -1069,6 +1097,7 @@ xfs_vm_writepage(
if (!buffer_uptodate(bh))
uptodate = 0;
+ is_cow = false;
/*
* set_page_dirty dirties all buffers in a page, independent
* of their state. The dirty state however is entirely
@@ -1091,7 +1120,15 @@ xfs_vm_writepage(
imap_valid = 0;
}
} else if (buffer_uptodate(bh)) {
- if (type != XFS_IO_OVERWRITE) {
+ if (xfs_sb_version_hasreflink(&ip->i_mount->m_sb)) {
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ is_cow = xfs_reflink_is_cow_pending(ip,
+ offset);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ }
+
+ if (type != XFS_IO_OVERWRITE ||
+ is_cow != was_cow) {
type = XFS_IO_OVERWRITE;
imap_valid = 0;
}
@@ -1121,23 +1158,23 @@ xfs_vm_writepage(
*/
new_ioend = 1;
err = xfs_map_blocks(inode, offset, &imap, type,
- nonblocking);
+ nonblocking, is_cow);
if (err)
goto error;
imap_valid = xfs_imap_valid(inode, &imap, offset);
}
if (imap_valid) {
lock_buffer(bh);
- if (type != XFS_IO_OVERWRITE)
+ if (type != XFS_IO_OVERWRITE || is_cow)
xfs_map_at_offset(inode, bh, &imap, offset);
xfs_add_to_ioend(inode, bh, offset, type, &ioend,
- new_ioend);
+ new_ioend, is_cow);
count++;
}
if (!iohead)
iohead = ioend;
-
+ was_cow = is_cow;
} while (offset += len, ((bh = bh->b_this_page) != head));
if (uptodate && bh == head)
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index f6ffc9a..ac59548 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -34,6 +34,8 @@ enum {
{ XFS_IO_UNWRITTEN, "unwritten" }, \
{ XFS_IO_OVERWRITE, "overwrite" }
+#define XFS_IOEND_COW (1)
+
/*
* xfs_ioend struct manages large extent writes for XFS.
* It can manage several multi-page bio's at once.
@@ -50,8 +52,16 @@ typedef struct xfs_ioend {
xfs_off_t io_offset; /* offset in the file */
struct work_struct io_work; /* xfsdatad work queue */
struct xfs_trans *io_append_trans;/* xact. for size update */
+ unsigned long io_flags; /* status flags */
} xfs_ioend_t;
+static inline bool
+xfs_ioend_is_cow(
+ struct xfs_ioend *ioend)
+{
+ return ioend->io_flags & XFS_IOEND_COW;
+}
+
extern const struct address_space_operations xfs_address_space_operations;
int xfs_get_blocks(struct inode *inode, sector_t offset,
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index fdc538e..65d4c2d 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -249,3 +249,75 @@ xfs_reflink_reserve_cow_range(
trace_xfs_reflink_reserve_cow_range_error(ip, error, _RET_IP_);
return error;
}
+
+/**
+ * xfs_reflink_is_cow_pending() -- Determine if CoW is pending for a given
+ * file and offset.
+ *
+ * @ip: XFS inode object.
+ * @offset: The file offset, in bytes.
+ */
+bool
+xfs_reflink_is_cow_pending(
+ struct xfs_inode *ip,
+ xfs_off_t offset)
+{
+ struct xfs_ifork *ifp;
+ struct xfs_bmbt_rec_host *gotp;
+ struct xfs_bmbt_irec irec;
+ xfs_fileoff_t bno;
+ xfs_extnum_t idx;
+
+ if (!xfs_is_reflink_inode(ip))
+ return false;
+
+ ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+ bno = XFS_B_TO_FSBT(ip->i_mount, offset);
+ gotp = xfs_iext_bno_to_ext(ifp, bno, &idx);
+
+ if (!gotp)
+ return false;
+
+ xfs_bmbt_get_all(gotp, &irec);
+ if (bno >= irec.br_startoff + irec.br_blockcount ||
+ bno < irec.br_startoff)
+ return false;
+ return true;
+}
+
+/**
+ * xfs_reflink_find_cow_mapping() -- Find the mapping for a CoW block.
+ *
+ * @ip: The XFS inode object.
+ * @offset: The file offset, in bytes.
+ * @imap: The mapping we're going to use for this block.
+ * @nimaps: Number of mappings we're returning.
+ */
+int
+xfs_reflink_find_cow_mapping(
+ struct xfs_inode *ip,
+ xfs_off_t offset,
+ struct xfs_bmbt_irec *imap,
+ bool *need_alloc)
+{
+ struct xfs_bmbt_irec irec;
+ struct xfs_ifork *ifp;
+ struct xfs_bmbt_rec_host *gotp;
+ xfs_fileoff_t bno;
+ xfs_extnum_t idx;
+
+ /* Find the extent in the CoW fork. */
+ ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+ bno = XFS_B_TO_FSBT(ip->i_mount, offset);
+ gotp = xfs_iext_bno_to_ext(ifp, bno, &idx);
+ xfs_bmbt_get_all(gotp, &irec);
+
+ trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE,
+ &irec);
+
+ /* If it's still delalloc, we must allocate later. */
+ *imap = irec;
+ *need_alloc = !!(isnullstartblock(irec.br_startblock));
+
+ return 0;
+}
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 41afdbe..1018ac9 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -20,5 +20,8 @@
extern int xfs_reflink_reserve_cow_range(struct xfs_inode *ip, xfs_off_t pos,
xfs_off_t len);
+extern bool xfs_reflink_is_cow_pending(struct xfs_inode *ip, xfs_off_t offset);
+extern int xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
+ struct xfs_bmbt_irec *imap, bool *need_alloc);
#endif /* __XFS_REFLINK_H */
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