xfs: introduce the CoW fork
Introduce a new in-core fork for storing copy-on-write delalloc
reservations and allocated extents that are in the process of being
written out.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 2be1fd3..dc24dd0 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -2924,6 +2924,7 @@
ASSERT(!isnullstartblock(new->br_startblock));
ASSERT(!bma->cur ||
!(bma->cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL));
+ ASSERT(whichfork != XFS_COW_FORK);
XFS_STATS_INC(mp, xs_add_exlist);
@@ -4072,12 +4073,11 @@
int error;
int eof;
int n = 0;
- int whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
- XFS_ATTR_FORK : XFS_DATA_FORK;
+ int whichfork = xfs_bmapi_whichfork(flags);
ASSERT(*nmap >= 1);
ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK|XFS_BMAPI_ENTIRE|
- XFS_BMAPI_IGSTATE)));
+ XFS_BMAPI_IGSTATE|XFS_BMAPI_COWFORK)));
ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED|XFS_ILOCK_EXCL));
if (unlikely(XFS_TEST_ERROR(
@@ -4095,6 +4095,16 @@
ifp = XFS_IFORK_PTR(ip, whichfork);
+ /* No CoW fork? Return a hole. */
+ if (whichfork == XFS_COW_FORK && !ifp) {
+ mval->br_startoff = bno;
+ mval->br_startblock = HOLESTARTBLOCK;
+ mval->br_blockcount = len;
+ mval->br_state = XFS_EXT_NORM;
+ *nmap = 1;
+ return 0;
+ }
+
if (!(ifp->if_flags & XFS_IFEXTENTS)) {
error = xfs_iread_extents(NULL, ip, whichfork);
if (error)
@@ -4368,8 +4378,7 @@
xfs_filblks_t len,
int flags)
{
- int whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
- XFS_ATTR_FORK : XFS_DATA_FORK;
+ int whichfork = xfs_bmapi_whichfork(flags);
struct xfs_ifork *ifp = XFS_IFORK_PTR(bma->ip, whichfork);
int tmp_logflags = 0;
int error;
@@ -4385,6 +4394,8 @@
(XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT))
return 0;
+ ASSERT(whichfork != XFS_COW_FORK);
+
/*
* Modify (by adding) the state flag, if writing.
*/
@@ -4795,6 +4806,8 @@
if (whichfork == XFS_ATTR_FORK)
state |= BMAP_ATTRFORK;
+ else if (whichfork == XFS_COW_FORK)
+ state |= BMAP_COWFORK;
ifp = XFS_IFORK_PTR(ip, whichfork);
ASSERT((*idx >= 0) && (*idx < ifp->if_bytes /
@@ -5133,8 +5146,8 @@
trace_xfs_bunmap(ip, bno, len, flags, _RET_IP_);
- whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
- XFS_ATTR_FORK : XFS_DATA_FORK;
+ whichfork = xfs_bmapi_whichfork(flags);
+ ASSERT(whichfork != XFS_COW_FORK);
ifp = XFS_IFORK_PTR(ip, whichfork);
if (unlikely(
XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index 85e3b9d..8774127 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -107,6 +107,9 @@
*/
#define XFS_BMAPI_REMAP 0x100
+/* Map something in the CoW fork. */
+#define XFS_BMAPI_COWFORK 0x200
+
#define XFS_BMAPI_FLAGS \
{ XFS_BMAPI_ENTIRE, "ENTIRE" }, \
{ XFS_BMAPI_METADATA, "METADATA" }, \
@@ -116,12 +119,23 @@
{ XFS_BMAPI_CONTIG, "CONTIG" }, \
{ XFS_BMAPI_CONVERT, "CONVERT" }, \
{ XFS_BMAPI_ZERO, "ZERO" }, \
- { XFS_BMAPI_REMAP, "REMAP" }
+ { XFS_BMAPI_REMAP, "REMAP" }, \
+ { XFS_BMAPI_COWFORK, "COWFORK" }
static inline int xfs_bmapi_aflag(int w)
{
- return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
+ return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK :
+ (w == XFS_COW_FORK ? XFS_BMAPI_COWFORK : 0));
+}
+
+static inline int xfs_bmapi_whichfork(int bmapi_flags)
+{
+ if (bmapi_flags & XFS_BMAPI_COWFORK)
+ return XFS_COW_FORK;
+ else if (bmapi_flags & XFS_BMAPI_ATTRFORK)
+ return XFS_ATTR_FORK;
+ return XFS_DATA_FORK;
}
/*
@@ -142,13 +156,15 @@
#define BMAP_LEFT_VALID (1 << 6)
#define BMAP_RIGHT_VALID (1 << 7)
#define BMAP_ATTRFORK (1 << 8)
+#define BMAP_COWFORK (1 << 9)
#define XFS_BMAP_EXT_FLAGS \
{ BMAP_LEFT_CONTIG, "LC" }, \
{ BMAP_RIGHT_CONTIG, "RC" }, \
{ BMAP_LEFT_FILLING, "LF" }, \
{ BMAP_RIGHT_FILLING, "RF" }, \
- { BMAP_ATTRFORK, "ATTR" }
+ { BMAP_ATTRFORK, "ATTR" }, \
+ { BMAP_COWFORK, "COW" }
/*
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index cd85274..37f0d9d 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -777,6 +777,7 @@
{
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
struct xfs_btree_cur *cur;
+ ASSERT(whichfork != XFS_COW_FORK);
cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 7699a03..5dd56d3 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -206,9 +206,14 @@
XFS_ERROR_REPORT("xfs_iformat(7)", XFS_ERRLEVEL_LOW, ip->i_mount);
return -EFSCORRUPTED;
}
- if (error) {
+ if (error)
return error;
+
+ if (xfs_is_reflink_inode(ip)) {
+ ASSERT(ip->i_cowfp == NULL);
+ xfs_ifork_init_cow(ip);
}
+
if (!XFS_DFORK_Q(dip))
return 0;
@@ -247,6 +252,9 @@
if (error) {
kmem_zone_free(xfs_ifork_zone, ip->i_afp);
ip->i_afp = NULL;
+ if (ip->i_cowfp)
+ kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
+ ip->i_cowfp = NULL;
xfs_idestroy_fork(ip, XFS_DATA_FORK);
}
return error;
@@ -761,6 +769,9 @@
if (whichfork == XFS_ATTR_FORK) {
kmem_zone_free(xfs_ifork_zone, ip->i_afp);
ip->i_afp = NULL;
+ } else if (whichfork == XFS_COW_FORK) {
+ kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
+ ip->i_cowfp = NULL;
}
}
@@ -948,6 +959,19 @@
}
}
+/* Convert bmap state flags to an inode fork. */
+struct xfs_ifork *
+xfs_iext_state_to_fork(
+ struct xfs_inode *ip,
+ int state)
+{
+ if (state & BMAP_COWFORK)
+ return ip->i_cowfp;
+ else if (state & BMAP_ATTRFORK)
+ return ip->i_afp;
+ return &ip->i_df;
+}
+
/*
* Insert new item(s) into the extent records for incore inode
* fork 'ifp'. 'count' new items are inserted at index 'idx'.
@@ -960,7 +984,7 @@
xfs_bmbt_irec_t *new, /* items to insert */
int state) /* type of extent conversion */
{
- xfs_ifork_t *ifp = (state & BMAP_ATTRFORK) ? ip->i_afp : &ip->i_df;
+ xfs_ifork_t *ifp = xfs_iext_state_to_fork(ip, state);
xfs_extnum_t i; /* extent record index */
trace_xfs_iext_insert(ip, idx, new, state, _RET_IP_);
@@ -1210,7 +1234,7 @@
int ext_diff, /* number of extents to remove */
int state) /* type of extent conversion */
{
- xfs_ifork_t *ifp = (state & BMAP_ATTRFORK) ? ip->i_afp : &ip->i_df;
+ xfs_ifork_t *ifp = xfs_iext_state_to_fork(ip, state);
xfs_extnum_t nextents; /* number of extents in file */
int new_size; /* size of extents after removal */
@@ -1955,3 +1979,20 @@
ifp->if_u1.if_ext_irec[i].er_extoff += ext_diff;
}
}
+
+/*
+ * Initialize an inode's copy-on-write fork.
+ */
+void
+xfs_ifork_init_cow(
+ struct xfs_inode *ip)
+{
+ if (ip->i_cowfp)
+ return;
+
+ ip->i_cowfp = kmem_zone_zalloc(xfs_ifork_zone,
+ KM_SLEEP | KM_NOFS);
+ ip->i_cowfp->if_flags = XFS_IFEXTENTS;
+ ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
+ ip->i_cnextents = 0;
+}
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index f95e072..c9476f5 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h
@@ -92,7 +92,9 @@
#define XFS_IFORK_PTR(ip,w) \
((w) == XFS_DATA_FORK ? \
&(ip)->i_df : \
- (ip)->i_afp)
+ ((w) == XFS_ATTR_FORK ? \
+ (ip)->i_afp : \
+ (ip)->i_cowfp))
#define XFS_IFORK_DSIZE(ip) \
(XFS_IFORK_Q(ip) ? \
XFS_IFORK_BOFF(ip) : \
@@ -105,26 +107,38 @@
#define XFS_IFORK_SIZE(ip,w) \
((w) == XFS_DATA_FORK ? \
XFS_IFORK_DSIZE(ip) : \
- XFS_IFORK_ASIZE(ip))
+ ((w) == XFS_ATTR_FORK ? \
+ XFS_IFORK_ASIZE(ip) : \
+ 0))
#define XFS_IFORK_FORMAT(ip,w) \
((w) == XFS_DATA_FORK ? \
(ip)->i_d.di_format : \
- (ip)->i_d.di_aformat)
+ ((w) == XFS_ATTR_FORK ? \
+ (ip)->i_d.di_aformat : \
+ (ip)->i_cformat))
#define XFS_IFORK_FMT_SET(ip,w,n) \
((w) == XFS_DATA_FORK ? \
((ip)->i_d.di_format = (n)) : \
- ((ip)->i_d.di_aformat = (n)))
+ ((w) == XFS_ATTR_FORK ? \
+ ((ip)->i_d.di_aformat = (n)) : \
+ ((ip)->i_cformat = (n))))
#define XFS_IFORK_NEXTENTS(ip,w) \
((w) == XFS_DATA_FORK ? \
(ip)->i_d.di_nextents : \
- (ip)->i_d.di_anextents)
+ ((w) == XFS_ATTR_FORK ? \
+ (ip)->i_d.di_anextents : \
+ (ip)->i_cnextents))
#define XFS_IFORK_NEXT_SET(ip,w,n) \
((w) == XFS_DATA_FORK ? \
((ip)->i_d.di_nextents = (n)) : \
- ((ip)->i_d.di_anextents = (n)))
+ ((w) == XFS_ATTR_FORK ? \
+ ((ip)->i_d.di_anextents = (n)) : \
+ ((ip)->i_cnextents = (n))))
#define XFS_IFORK_MAXEXT(ip, w) \
(XFS_IFORK_SIZE(ip, w) / sizeof(xfs_bmbt_rec_t))
+struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
+
int xfs_iformat_fork(struct xfs_inode *, struct xfs_dinode *);
void xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
struct xfs_inode_log_item *, int);
@@ -169,4 +183,6 @@
extern struct kmem_zone *xfs_ifork_zone;
+extern void xfs_ifork_init_cow(struct xfs_inode *ip);
+
#endif /* __XFS_INODE_FORK_H__ */
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
index 73d0540..1c40b85 100644
--- a/fs/xfs/libxfs/xfs_rmap.c
+++ b/fs/xfs/libxfs/xfs_rmap.c
@@ -1263,9 +1263,10 @@
*/
static bool
xfs_rmap_update_is_needed(
- struct xfs_mount *mp)
+ struct xfs_mount *mp,
+ int whichfork)
{
- return xfs_sb_version_hasrmapbt(&mp->m_sb);
+ return xfs_sb_version_hasrmapbt(&mp->m_sb) && whichfork != XFS_COW_FORK;
}
/*
@@ -1311,7 +1312,7 @@
int whichfork,
struct xfs_bmbt_irec *PREV)
{
- if (!xfs_rmap_update_is_needed(mp))
+ if (!xfs_rmap_update_is_needed(mp, whichfork))
return 0;
return __xfs_rmap_add(mp, dfops, XFS_RMAP_MAP, ip->i_ino,
@@ -1327,7 +1328,7 @@
int whichfork,
struct xfs_bmbt_irec *PREV)
{
- if (!xfs_rmap_update_is_needed(mp))
+ if (!xfs_rmap_update_is_needed(mp, whichfork))
return 0;
return __xfs_rmap_add(mp, dfops, XFS_RMAP_UNMAP, ip->i_ino,
@@ -1343,7 +1344,7 @@
int whichfork,
struct xfs_bmbt_irec *PREV)
{
- if (!xfs_rmap_update_is_needed(mp))
+ if (!xfs_rmap_update_is_needed(mp, whichfork))
return 0;
return __xfs_rmap_add(mp, dfops, XFS_RMAP_CONVERT, ip->i_ino,
@@ -1362,7 +1363,7 @@
{
struct xfs_bmbt_irec bmap;
- if (!xfs_rmap_update_is_needed(mp))
+ if (!xfs_rmap_update_is_needed(mp, XFS_DATA_FORK))
return 0;
bmap.br_startblock = XFS_AGB_TO_FSB(mp, agno, bno);
@@ -1386,7 +1387,7 @@
{
struct xfs_bmbt_irec bmap;
- if (!xfs_rmap_update_is_needed(mp))
+ if (!xfs_rmap_update_is_needed(mp, XFS_DATA_FORK))
return 0;
bmap.br_startblock = XFS_AGB_TO_FSB(mp, agno, bno);
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index be7b6de..8d74870 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -90,6 +90,7 @@
*/
#define XFS_DATA_FORK 0
#define XFS_ATTR_FORK 1
+#define XFS_COW_FORK 2
/*
* Min numbers of data/attr fork btree root pointers.