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authorDave Chinner <dchinner@redhat.com>2011-09-18 16:40:44 -0400
committerAlex Elder <aelder@sgi.com>2011-10-11 22:15:03 -0400
commitaef9a89586fc8475bf0333b8736d5aa8aa6f4897 (patch)
treec9f7a1d4744335f7bc36dd4b06b223af440cc170 /fs/xfs/xfs_bmap.c
parentecee76ba9d91fdcbdff933ca1bd41465ca4c4fdb (diff)
xfs: factor extent map manipulations out of xfs_bmapi
To further improve the readability of xfs_bmapi(), factor the pure extent map manipulations out into separate functions. This removes large blocks of logic from the xfs_bmapi() code loop and makes it easier to see the operational logic flow for xfs_bmapi(). Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_bmap.c')
-rw-r--r--fs/xfs/xfs_bmap.c181
1 files changed, 107 insertions, 74 deletions
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 05d38adbb85..59f63949d3b 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -4249,6 +4249,107 @@ xfs_bmap_validate_ret(
4249 4249
4250 4250
4251/* 4251/*
4252 * Trim the returned map to the required bounds
4253 */
4254STATIC void
4255xfs_bmapi_trim_map(
4256 struct xfs_bmbt_irec *mval,
4257 struct xfs_bmbt_irec *got,
4258 xfs_fileoff_t *bno,
4259 xfs_filblks_t len,
4260 xfs_fileoff_t obno,
4261 xfs_fileoff_t end,
4262 int n,
4263 int flags)
4264{
4265 if ((flags & XFS_BMAPI_ENTIRE) ||
4266 got->br_startoff + got->br_blockcount <= obno) {
4267 *mval = *got;
4268 if (isnullstartblock(got->br_startblock))
4269 mval->br_startblock = DELAYSTARTBLOCK;
4270 return;
4271 }
4272
4273 if (obno > *bno)
4274 *bno = obno;
4275 ASSERT((*bno >= obno) || (n == 0));
4276 ASSERT(*bno < end);
4277 mval->br_startoff = *bno;
4278 if (isnullstartblock(got->br_startblock))
4279 mval->br_startblock = DELAYSTARTBLOCK;
4280 else
4281 mval->br_startblock = got->br_startblock +
4282 (*bno - got->br_startoff);
4283 /*
4284 * Return the minimum of what we got and what we asked for for
4285 * the length. We can use the len variable here because it is
4286 * modified below and we could have been there before coming
4287 * here if the first part of the allocation didn't overlap what
4288 * was asked for.
4289 */
4290 mval->br_blockcount = XFS_FILBLKS_MIN(end - *bno,
4291 got->br_blockcount - (*bno - got->br_startoff));
4292 mval->br_state = got->br_state;
4293 ASSERT(mval->br_blockcount <= len);
4294 return;
4295}
4296
4297/*
4298 * Update and validate the extent map to return
4299 */
4300STATIC void
4301xfs_bmapi_update_map(
4302 struct xfs_bmbt_irec **map,
4303 xfs_fileoff_t *bno,
4304 xfs_filblks_t *len,
4305 xfs_fileoff_t obno,
4306 xfs_fileoff_t end,
4307 int *n,
4308 int flags)
4309{
4310 xfs_bmbt_irec_t *mval = *map;
4311
4312 ASSERT((flags & XFS_BMAPI_ENTIRE) ||
4313 ((mval->br_startoff + mval->br_blockcount) <= end));
4314 ASSERT((flags & XFS_BMAPI_ENTIRE) || (mval->br_blockcount <= *len) ||
4315 (mval->br_startoff < obno));
4316
4317 *bno = mval->br_startoff + mval->br_blockcount;
4318 *len = end - *bno;
4319 if (*n > 0 && mval->br_startoff == mval[-1].br_startoff) {
4320 /* update previous map with new information */
4321 ASSERT(mval->br_startblock == mval[-1].br_startblock);
4322 ASSERT(mval->br_blockcount > mval[-1].br_blockcount);
4323 ASSERT(mval->br_state == mval[-1].br_state);
4324 mval[-1].br_blockcount = mval->br_blockcount;
4325 mval[-1].br_state = mval->br_state;
4326 } else if (*n > 0 && mval->br_startblock != DELAYSTARTBLOCK &&
4327 mval[-1].br_startblock != DELAYSTARTBLOCK &&
4328 mval[-1].br_startblock != HOLESTARTBLOCK &&
4329 mval->br_startblock == mval[-1].br_startblock +
4330 mval[-1].br_blockcount &&
4331 ((flags & XFS_BMAPI_IGSTATE) ||
4332 mval[-1].br_state == mval->br_state)) {
4333 ASSERT(mval->br_startoff ==
4334 mval[-1].br_startoff + mval[-1].br_blockcount);
4335 mval[-1].br_blockcount += mval->br_blockcount;
4336 } else if (*n > 0 &&
4337 mval->br_startblock == DELAYSTARTBLOCK &&
4338 mval[-1].br_startblock == DELAYSTARTBLOCK &&
4339 mval->br_startoff ==
4340 mval[-1].br_startoff + mval[-1].br_blockcount) {
4341 mval[-1].br_blockcount += mval->br_blockcount;
4342 mval[-1].br_state = mval->br_state;
4343 } else if (!((*n == 0) &&
4344 ((mval->br_startoff + mval->br_blockcount) <=
4345 obno))) {
4346 mval++;
4347 (*n)++;
4348 }
4349 *map = mval;
4350}
4351
4352/*
4252 * Map file blocks to filesystem blocks. 4353 * Map file blocks to filesystem blocks.
4253 * File range is given by the bno/len pair. 4354 * File range is given by the bno/len pair.
4254 * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set) 4355 * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
@@ -4650,44 +4751,9 @@ xfs_bmapi(
4650 n++; 4751 n++;
4651 continue; 4752 continue;
4652 } 4753 }
4653 /* 4754
4654 * Then deal with the allocated space we found. 4755 /* Deal with the allocated space we found. */
4655 */ 4756 xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
4656 ASSERT(ep != NULL);
4657 if (!(flags & XFS_BMAPI_ENTIRE) &&
4658 (got.br_startoff + got.br_blockcount > obno)) {
4659 if (obno > bno)
4660 bno = obno;
4661 ASSERT((bno >= obno) || (n == 0));
4662 ASSERT(bno < end);
4663 mval->br_startoff = bno;
4664 if (isnullstartblock(got.br_startblock)) {
4665 ASSERT(!wr || (flags & XFS_BMAPI_DELAY));
4666 mval->br_startblock = DELAYSTARTBLOCK;
4667 } else
4668 mval->br_startblock =
4669 got.br_startblock +
4670 (bno - got.br_startoff);
4671 /*
4672 * Return the minimum of what we got and what we
4673 * asked for for the length. We can use the len
4674 * variable here because it is modified below
4675 * and we could have been there before coming
4676 * here if the first part of the allocation
4677 * didn't overlap what was asked for.
4678 */
4679 mval->br_blockcount =
4680 XFS_FILBLKS_MIN(end - bno, got.br_blockcount -
4681 (bno - got.br_startoff));
4682 mval->br_state = got.br_state;
4683 ASSERT(mval->br_blockcount <= len);
4684 } else {
4685 *mval = got;
4686 if (isnullstartblock(mval->br_startblock)) {
4687 ASSERT(!wr || (flags & XFS_BMAPI_DELAY));
4688 mval->br_startblock = DELAYSTARTBLOCK;
4689 }
4690 }
4691 4757
4692 /* 4758 /*
4693 * Check if writing previously allocated but 4759 * Check if writing previously allocated but
@@ -4730,42 +4796,9 @@ xfs_bmapi(
4730 continue; 4796 continue;
4731 } 4797 }
4732 4798
4733 ASSERT((flags & XFS_BMAPI_ENTIRE) || 4799 /* update the extent map to return */
4734 ((mval->br_startoff + mval->br_blockcount) <= end)); 4800 xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
4735 ASSERT((flags & XFS_BMAPI_ENTIRE) || 4801
4736 (mval->br_blockcount <= len) ||
4737 (mval->br_startoff < obno));
4738 bno = mval->br_startoff + mval->br_blockcount;
4739 len = end - bno;
4740 if (n > 0 && mval->br_startoff == mval[-1].br_startoff) {
4741 ASSERT(mval->br_startblock == mval[-1].br_startblock);
4742 ASSERT(mval->br_blockcount > mval[-1].br_blockcount);
4743 ASSERT(mval->br_state == mval[-1].br_state);
4744 mval[-1].br_blockcount = mval->br_blockcount;
4745 mval[-1].br_state = mval->br_state;
4746 } else if (n > 0 && mval->br_startblock != DELAYSTARTBLOCK &&
4747 mval[-1].br_startblock != DELAYSTARTBLOCK &&
4748 mval[-1].br_startblock != HOLESTARTBLOCK &&
4749 mval->br_startblock ==
4750 mval[-1].br_startblock + mval[-1].br_blockcount &&
4751 ((flags & XFS_BMAPI_IGSTATE) ||
4752 mval[-1].br_state == mval->br_state)) {
4753 ASSERT(mval->br_startoff ==
4754 mval[-1].br_startoff + mval[-1].br_blockcount);
4755 mval[-1].br_blockcount += mval->br_blockcount;
4756 } else if (n > 0 &&
4757 mval->br_startblock == DELAYSTARTBLOCK &&
4758 mval[-1].br_startblock == DELAYSTARTBLOCK &&
4759 mval->br_startoff ==
4760 mval[-1].br_startoff + mval[-1].br_blockcount) {
4761 mval[-1].br_blockcount += mval->br_blockcount;
4762 mval[-1].br_state = mval->br_state;
4763 } else if (!((n == 0) &&
4764 ((mval->br_startoff + mval->br_blockcount) <=
4765 obno))) {
4766 mval++;
4767 n++;
4768 }
4769 /* 4802 /*
4770 * If we're done, stop now. Stop when we've allocated 4803 * If we're done, stop now. Stop when we've allocated
4771 * XFS_BMAP_MAX_NMAP extents no matter what. Otherwise 4804 * XFS_BMAP_MAX_NMAP extents no matter what. Otherwise
generated by cgit v1.2.2 (git 2.25.0) at 2024-10-19 16:03:50 -0400