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xfs: introduce xfs_bmapi_delay()
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Delalloc reservations are much simpler than allocations, so give
them a separate bmapi-level interface.  Using the previously added
xfs_bmapi_reserve_delalloc we get a function that is only minimally
more complicated than xfs_bmapi_read, which is far from the complexity
in xfs_bmapi.  Also remove the XFS_BMAPI_DELAY code after switching
over the only user to xfs_bmapi_delay.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
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Christoph Hellwig authored and Alex Elder committed Oct 12, 2011
1 parent b64dfe4 commit 4403280
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Showing 3 changed files with 94 additions and 35 deletions.
115 changes: 89 additions & 26 deletions fs/xfs/xfs_bmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4238,7 +4238,7 @@ xfs_bmap_validate_ret(
ASSERT(i == 0 ||
mval[i - 1].br_startoff + mval[i - 1].br_blockcount ==
mval[i].br_startoff);
if ((flags & XFS_BMAPI_WRITE) && !(flags & XFS_BMAPI_DELAY))
if (flags & XFS_BMAPI_WRITE)
ASSERT(mval[i].br_startblock != DELAYSTARTBLOCK &&
mval[i].br_startblock != HOLESTARTBLOCK);
ASSERT(mval[i].br_state == XFS_EXT_NORM ||
Expand Down Expand Up @@ -4555,6 +4555,90 @@ xfs_bmapi_reserve_delalloc(
return error;
}

/*
* Map file blocks to filesystem blocks, adding delayed allocations as needed.
*/
int
xfs_bmapi_delay(
struct xfs_inode *ip, /* incore inode */
xfs_fileoff_t bno, /* starting file offs. mapped */
xfs_filblks_t len, /* length to map in file */
struct xfs_bmbt_irec *mval, /* output: map values */
int *nmap, /* i/o: mval size/count */
int flags) /* XFS_BMAPI_... */
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
struct xfs_bmbt_irec got; /* current file extent record */
struct xfs_bmbt_irec prev; /* previous file extent record */
xfs_fileoff_t obno; /* old block number (offset) */
xfs_fileoff_t end; /* end of mapped file region */
xfs_extnum_t lastx; /* last useful extent number */
int eof; /* we've hit the end of extents */
int n = 0; /* current extent index */
int error = 0;

ASSERT(*nmap >= 1);
ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
ASSERT(!(flags & ~XFS_BMAPI_ENTIRE));

if (unlikely(XFS_TEST_ERROR(
(XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS &&
XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE),
mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
XFS_ERROR_REPORT("xfs_bmapi_delay", XFS_ERRLEVEL_LOW, mp);
return XFS_ERROR(EFSCORRUPTED);
}

if (XFS_FORCED_SHUTDOWN(mp))
return XFS_ERROR(EIO);

XFS_STATS_INC(xs_blk_mapw);

if (!(ifp->if_flags & XFS_IFEXTENTS)) {
error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
if (error)
return error;
}

xfs_bmap_search_extents(ip, bno, XFS_DATA_FORK, &eof, &lastx, &got, &prev);
end = bno + len;
obno = bno;

while (bno < end && n < *nmap) {
if (eof || got.br_startoff > bno) {
error = xfs_bmapi_reserve_delalloc(ip, bno, len, &got,
&prev, &lastx, eof);
if (error) {
if (n == 0) {
*nmap = 0;
return error;
}
break;
}
}

/* set up the extent map to return. */
xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);

/* If we're done, stop now. */
if (bno >= end || n >= *nmap)
break;

/* Else go on to the next record. */
prev = got;
if (++lastx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t))
xfs_bmbt_get_all(xfs_iext_get_ext(ifp, lastx), &got);
else
eof = 1;
}

*nmap = n;
return 0;
}


/*
* Map file blocks to filesystem blocks.
* File range is given by the bno/len pair.
Expand Down Expand Up @@ -4663,7 +4747,6 @@ xfs_bmapi(
*/
if ((flags & XFS_BMAPI_IGSTATE) && wr) /* if writing unwritten space */
wr = 0; /* no allocations are allowed */
ASSERT(wr || !(flags & XFS_BMAPI_DELAY));
logflags = 0;
nallocs = 0;
cur = NULL;
Expand Down Expand Up @@ -4698,8 +4781,7 @@ xfs_bmapi(
if (eof && !wr)
got.br_startoff = end;
inhole = eof || got.br_startoff > bno;
wasdelay = wr && !inhole && !(flags & XFS_BMAPI_DELAY) &&
isnullstartblock(got.br_startblock);
wasdelay = wr && !inhole && isnullstartblock(got.br_startblock);
/*
* First, deal with the hole before the allocated space
* that we found, if any.
Expand Down Expand Up @@ -4727,20 +4809,7 @@ xfs_bmapi(
aoff = bno;
}
minlen = (flags & XFS_BMAPI_CONTIG) ? alen : 1;
if (flags & XFS_BMAPI_DELAY) {
error = xfs_bmapi_reserve_delalloc(ip, bno, len, &got,
&prev, &lastx, eof);
if (error) {
if (n == 0) {
*nmap = 0;
ASSERT(cur == NULL);
return error;
}
break;
}

goto trim_extent;
} else {
{
/*
* If first time, allocate and fill in
* once-only bma fields.
Expand Down Expand Up @@ -4851,14 +4920,8 @@ xfs_bmapi(
ASSERT(got.br_startoff <= aoff);
ASSERT(got.br_startoff + got.br_blockcount >=
aoff + alen);
#ifdef DEBUG
if (flags & XFS_BMAPI_DELAY) {
ASSERT(isnullstartblock(got.br_startblock));
ASSERT(startblockval(got.br_startblock) > 0);
}
ASSERT(got.br_state == XFS_EXT_NORM ||
got.br_state == XFS_EXT_UNWRITTEN);
#endif
/*
* Fall down into the found allocated space case.
*/
Expand All @@ -4877,7 +4940,7 @@ xfs_bmapi(
n++;
continue;
}
trim_extent:

/* Deal with the allocated space we found. */
xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);

Expand All @@ -4887,7 +4950,7 @@ xfs_bmapi(
*/
if (wr &&
((mval->br_state == XFS_EXT_UNWRITTEN &&
((flags & (XFS_BMAPI_PREALLOC|XFS_BMAPI_DELAY)) == 0)) ||
((flags & XFS_BMAPI_PREALLOC) == 0)) ||
(mval->br_state == XFS_EXT_NORM &&
((flags & (XFS_BMAPI_PREALLOC|XFS_BMAPI_CONVERT)) ==
(XFS_BMAPI_PREALLOC|XFS_BMAPI_CONVERT))))) {
Expand Down
5 changes: 3 additions & 2 deletions fs/xfs/xfs_bmap.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,6 @@ typedef struct xfs_bmap_free
* Flags for xfs_bmapi
*/
#define XFS_BMAPI_WRITE 0x001 /* write operation: allocate space */
#define XFS_BMAPI_DELAY 0x002 /* delayed write operation */
#define XFS_BMAPI_ENTIRE 0x004 /* return entire extent, not trimmed */
#define XFS_BMAPI_METADATA 0x008 /* mapping metadata not user data */
#define XFS_BMAPI_ATTRFORK 0x010 /* use attribute fork not data */
Expand All @@ -82,7 +81,6 @@ typedef struct xfs_bmap_free

#define XFS_BMAPI_FLAGS \
{ XFS_BMAPI_WRITE, "WRITE" }, \
{ XFS_BMAPI_DELAY, "DELAY" }, \
{ XFS_BMAPI_ENTIRE, "ENTIRE" }, \
{ XFS_BMAPI_METADATA, "METADATA" }, \
{ XFS_BMAPI_ATTRFORK, "ATTRFORK" }, \
Expand Down Expand Up @@ -297,6 +295,9 @@ xfs_bmapi(
int xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
xfs_filblks_t len, struct xfs_bmbt_irec *mval,
int *nmap, int flags);
int xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
xfs_filblks_t len, struct xfs_bmbt_irec *mval,
int *nmap, int flags);

/*
* Unmap (remove) blocks from a file.
Expand Down
9 changes: 2 additions & 7 deletions fs/xfs/xfs_iomap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -381,7 +381,6 @@ xfs_iomap_write_delay(
xfs_fileoff_t last_fsb;
xfs_off_t aligned_offset;
xfs_fileoff_t ioalign;
xfs_fsblock_t firstblock;
xfs_extlen_t extsz;
int nimaps;
xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
Expand Down Expand Up @@ -425,12 +424,8 @@ xfs_iomap_write_delay(
}

nimaps = XFS_WRITE_IMAPS;
firstblock = NULLFSBLOCK;
error = xfs_bmapi(NULL, ip, offset_fsb,
(xfs_filblks_t)(last_fsb - offset_fsb),
XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
&nimaps, NULL);
error = xfs_bmapi_delay(ip, offset_fsb, last_fsb - offset_fsb,
imap, &nimaps, XFS_BMAPI_ENTIRE);
switch (error) {
case 0:
case ENOSPC:
Expand Down

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