Re: [PATCH 12/17] xfs: refactor xfs_bmap_add_extent_unwritten_real

Brian Foster
2017-09-08T17:19:02Z

On Sun, Sep 03, 2017 at 09:29:51AM +0200, Christoph Hellwig wrote:
> Use xfs_iext_get_extent to find, and xfs_iext_update_extent to update
> entries in the in-core extent list. This isolates the function from
> the detailed layout of the extent list, and generally makes the code
> a lot more readable.
>
> Also get rid of the oldext and newext variables as using the extent
> records is a lot more descriptive.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/libxfs/xfs_bmap.c | 208 +++++++++++++++++++++++------------------------
> 1 file changed, 104 insertions(+), 104 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index edea670a3f74..bc41fc18cceb 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -2171,18 +2171,16 @@ xfs_bmap_add_extent_unwritten_real(
> int *logflagsp) /* inode logging flags */
> {
> xfs_btree_cur_t *cur; /* btree cursor */
> - xfs_bmbt_rec_host_t *ep; /* extent entry for idx */
> int error; /* error return value */
> int i; /* temp state */
> xfs_ifork_t *ifp; /* inode fork pointer */
> xfs_fileoff_t new_endoff; /* end offset of new entry */
> - xfs_exntst_t newext; /* new extent state */
> - xfs_exntst_t oldext; /* old extent state */
> xfs_bmbt_irec_t r[3]; /* neighbor extent entries */
> /* left is 0, right is 1, prev is 2 */
> int rval=0; /* return value (logging flags) */
> int state = 0;/* state bits, accessed thru macros */
> struct xfs_mount *mp = ip->i_mount;
> + struct xfs_bmbt_irec old;
>
> *logflagsp = 0;
>
> @@ -2205,12 +2203,8 @@ xfs_bmap_add_extent_unwritten_real(
> * Set up a bunch of variables to make the tests simpler.
> */
> error = 0;
> - ep = xfs_iext_get_ext(ifp, *idx);
> - xfs_bmbt_get_all(ep, &PREV);
> - newext = new->br_state;
> - oldext = (newext == XFS_EXT_UNWRITTEN) ?
> - XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
> - ASSERT(PREV.br_state == oldext);
> + xfs_iext_get_extent(ifp, *idx, &PREV);
> + ASSERT(new->br_state != PREV.br_state);
> new_endoff = new->br_startoff + new->br_blockcount;
> ASSERT(PREV.br_startoff <= new->br_startoff);
> ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
> @@ -2239,7 +2233,7 @@ xfs_bmap_add_extent_unwritten_real(
> if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
> LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
> LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
> - LEFT.br_state == newext &&
> + LEFT.br_state == new->br_state &&
> LEFT.br_blockcount + new->br_blockcount <= MAXEXTLEN)
> state |= BMAP_LEFT_CONTIG;
>
> @@ -2258,7 +2252,7 @@ xfs_bmap_add_extent_unwritten_real(
> if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
> new_endoff == RIGHT.br_startoff &&
> new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
> - newext == RIGHT.br_state &&
> + new->br_state == RIGHT.br_state &&
> new->br_blockcount + RIGHT.br_blockcount <= MAXEXTLEN &&
> ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
> BMAP_RIGHT_FILLING)) !=
> @@ -2282,9 +2276,8 @@ xfs_bmap_add_extent_unwritten_real(
> --*idx;
>
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
> - LEFT.br_blockcount + PREV.br_blockcount +
> - RIGHT.br_blockcount);
> + LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &LEFT);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> xfs_iext_remove(ip, *idx + 1, 2, state);
> @@ -2311,10 +2304,10 @@ xfs_bmap_add_extent_unwritten_real(
> if ((error = xfs_btree_decrement(cur, 0, &i)))
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
> - LEFT.br_startblock,
> - LEFT.br_blockcount + PREV.br_blockcount +
> - RIGHT.br_blockcount, LEFT.br_state)))
> + error = xfs_bmbt_update(cur, LEFT.br_startoff,
> + LEFT.br_startblock, LEFT.br_blockcount,
> + LEFT.br_state);
> + if (error)
> goto done;
> }
> break;
> @@ -2327,8 +2320,8 @@ xfs_bmap_add_extent_unwritten_real(
> --*idx;
>
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
> - LEFT.br_blockcount + PREV.br_blockcount);
> + LEFT.br_blockcount += PREV.br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &LEFT);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> xfs_iext_remove(ip, *idx + 1, 1, state);
> @@ -2349,10 +2342,10 @@ xfs_bmap_add_extent_unwritten_real(
> if ((error = xfs_btree_decrement(cur, 0, &i)))
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
> - LEFT.br_startblock,
> - LEFT.br_blockcount + PREV.br_blockcount,
> - LEFT.br_state)))
> + error = xfs_bmbt_update(cur, LEFT.br_startoff,
> + LEFT.br_startblock, LEFT.br_blockcount,
> + LEFT.br_state);
> + if (error)
> goto done;
> }
> break;
> @@ -2363,10 +2356,11 @@ xfs_bmap_add_extent_unwritten_real(
> * The right neighbor is contiguous, the left is not.
> */
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(ep,
> - PREV.br_blockcount + RIGHT.br_blockcount);
> - xfs_bmbt_set_state(ep, newext);
> + PREV.br_blockcount += RIGHT.br_blockcount;
> + PREV.br_state = new->br_state;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
> +
> xfs_iext_remove(ip, *idx + 1, 1, state);
> XFS_IFORK_NEXT_SET(ip, whichfork,
> XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
> @@ -2385,10 +2379,10 @@ xfs_bmap_add_extent_unwritten_real(
> if ((error = xfs_btree_decrement(cur, 0, &i)))
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur, new->br_startoff,
> - new->br_startblock,
> - new->br_blockcount + RIGHT.br_blockcount,
> - newext)))
> + error = xfs_bmbt_update(cur, PREV.br_startoff,
> + PREV.br_startblock, PREV.br_blockcount,
> + PREV.br_state);
> + if (error)
> goto done;
> }
> break;
> @@ -2400,7 +2394,8 @@ xfs_bmap_add_extent_unwritten_real(
> * the new one.
> */
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_state(ep, newext);
> + PREV.br_state = new->br_state;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> if (cur == NULL)
> @@ -2412,9 +2407,10 @@ xfs_bmap_add_extent_unwritten_real(
> &i)))
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur, new->br_startoff,
> - new->br_startblock, new->br_blockcount,
> - newext)))
> + error = xfs_bmbt_update(cur, PREV.br_startoff,
> + PREV.br_startblock, PREV.br_blockcount,
> + PREV.br_state);
> + if (error)
> goto done;
> }
> break;
> @@ -2425,17 +2421,16 @@ xfs_bmap_add_extent_unwritten_real(
> * The left neighbor is contiguous.
> */
> trace_xfs_bmap_pre_update(ip, *idx - 1, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx - 1),
> - LEFT.br_blockcount + new->br_blockcount);
> - xfs_bmbt_set_startoff(ep,
> - PREV.br_startoff + new->br_blockcount);
> + LEFT.br_blockcount += new->br_blockcount;
> + xfs_iext_update_extent(ifp, *idx - 1, &LEFT);
> trace_xfs_bmap_post_update(ip, *idx - 1, state, _THIS_IP_);
>
> + old = PREV;
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_startblock(ep,
> - new->br_startblock + new->br_blockcount);
> - xfs_bmbt_set_blockcount(ep,
> - PREV.br_blockcount - new->br_blockcount);
> + PREV.br_startoff += new->br_blockcount;
> + PREV.br_startblock += new->br_blockcount;
> + PREV.br_blockcount -= new->br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> --*idx;
> @@ -2444,23 +2439,23 @@ xfs_bmap_add_extent_unwritten_real(
> rval = XFS_ILOG_DEXT;
> else {
> rval = 0;
> - if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
> - PREV.br_startblock, PREV.br_blockcount,
> - &i)))
> + error = xfs_bmbt_lookup_eq(cur, old.br_startoff,
> + old.br_startblock, old.br_blockcount,
> + &i);
> + if (error)
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur,
> - PREV.br_startoff + new->br_blockcount,
> - PREV.br_startblock + new->br_blockcount,
> - PREV.br_blockcount - new->br_blockcount,
> - oldext)))
> + error = xfs_bmbt_update(cur, PREV.br_startoff,
> + PREV.br_startblock, PREV.br_blockcount,
> + PREV.br_state);
> + if (error)
> goto done;
> - if ((error = xfs_btree_decrement(cur, 0, &i)))
> + error = xfs_btree_decrement(cur, 0, &i);
> + if (error)
> goto done;
> error = xfs_bmbt_update(cur, LEFT.br_startoff,
> - LEFT.br_startblock,
> - LEFT.br_blockcount + new->br_blockcount,
> - LEFT.br_state);
> + LEFT.br_startblock, LEFT.br_blockcount,
> + LEFT.br_state);
> if (error)
> goto done;
> }
> @@ -2471,13 +2466,12 @@ xfs_bmap_add_extent_unwritten_real(
> * Setting the first part of a previous oldext extent to newext.
> * The left neighbor is not contiguous.
> */
> + old = PREV;
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - ASSERT(ep && xfs_bmbt_get_state(ep) == oldext);
> - xfs_bmbt_set_startoff(ep, new_endoff);
> - xfs_bmbt_set_blockcount(ep,
> - PREV.br_blockcount - new->br_blockcount);
> - xfs_bmbt_set_startblock(ep,
> - new->br_startblock + new->br_blockcount);
> + PREV.br_startoff += new->br_blockcount;
> + PREV.br_startblock += new->br_blockcount;
> + PREV.br_blockcount -= new->br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> xfs_iext_insert(ip, *idx, 1, new, state);
> @@ -2487,16 +2481,16 @@ xfs_bmap_add_extent_unwritten_real(
> rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
> else {
> rval = XFS_ILOG_CORE;
> - if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
> - PREV.br_startblock, PREV.br_blockcount,
> - &i)))
> + error = xfs_bmbt_lookup_eq(cur, old.br_startoff,
> + old.br_startblock, old.br_blockcount,
> + &i);
> + if (error)
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur,
> - PREV.br_startoff + new->br_blockcount,
> - PREV.br_startblock + new->br_blockcount,
> - PREV.br_blockcount - new->br_blockcount,
> - oldext)))
> + error = xfs_bmbt_update(cur, PREV.br_startoff,
> + PREV.br_startblock, PREV.br_blockcount,
> + PREV.br_state);
> + if (error)
> goto done;
> cur->bc_rec.b = *new;
> if ((error = xfs_btree_insert(cur, &i)))
> @@ -2510,39 +2504,43 @@ xfs_bmap_add_extent_unwritten_real(
> * Setting the last part of a previous oldext extent to newext.
> * The right neighbor is contiguous with the new allocation.
> */
> + old = PREV;
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(ep,
> - PREV.br_blockcount - new->br_blockcount);
> + PREV.br_blockcount -= new->br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> ++*idx;
>
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, *idx),
> - new->br_startoff, new->br_startblock,
> - new->br_blockcount + RIGHT.br_blockcount, newext);
> + RIGHT.br_startoff = new->br_startoff;
> + RIGHT.br_startblock = new->br_startblock;
> + RIGHT.br_blockcount += new->br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &RIGHT);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> if (cur == NULL)
> rval = XFS_ILOG_DEXT;
> else {
> rval = 0;
> - if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
> - PREV.br_startblock,
> - PREV.br_blockcount, &i)))
> + error = xfs_bmbt_lookup_eq(cur, old.br_startoff,
> + old.br_startblock, old.br_blockcount,
> + &i);
> + if (error)
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
> - PREV.br_startblock,
> - PREV.br_blockcount - new->br_blockcount,
> - oldext)))
> + error = xfs_bmbt_update(cur, PREV.br_startoff,
> + PREV.br_startblock, PREV.br_blockcount,
> + PREV.br_state);
> + if (error)
> goto done;
> - if ((error = xfs_btree_increment(cur, 0, &i)))
> + error = xfs_btree_increment(cur, 0, &i);
> + if (error)
> goto done;
> - if ((error = xfs_bmbt_update(cur, new->br_startoff,
> - new->br_startblock,
> - new->br_blockcount + RIGHT.br_blockcount,
> - newext)))
> + error = xfs_bmbt_update(cur, RIGHT.br_startoff,
> + RIGHT.br_startblock,
> + RIGHT.br_blockcount, RIGHT.br_state);
> + if (error)
> goto done;
> }
> break;
> @@ -2552,9 +2550,10 @@ xfs_bmap_add_extent_unwritten_real(
> * Setting the last part of a previous oldext extent to newext.
> * The right neighbor is not contiguous.
> */
> + old = PREV;
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(ep,
> - PREV.br_blockcount - new->br_blockcount);
> + PREV.br_blockcount -= new->br_blockcount;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> ++*idx;
> @@ -2566,15 +2565,16 @@ xfs_bmap_add_extent_unwritten_real(
> rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
> else {
> rval = XFS_ILOG_CORE;
> - if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
> - PREV.br_startblock, PREV.br_blockcount,
> - &i)))
> + error = xfs_bmbt_lookup_eq(cur, old.br_startoff,
> + old.br_startblock, old.br_blockcount,
> + &i);
> + if (error)
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> - if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
> - PREV.br_startblock,
> - PREV.br_blockcount - new->br_blockcount,
> - oldext)))
> + error = xfs_bmbt_update(cur, PREV.br_startoff,
> + PREV.br_startblock, PREV.br_blockcount,
> + PREV.br_state);
> + if (error)
> goto done;
> if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
> new->br_startblock, new->br_blockcount,
> @@ -2594,17 +2594,18 @@ xfs_bmap_add_extent_unwritten_real(
> * newext. Contiguity is impossible here.
> * One extent becomes three extents.
> */
> + old = PREV;
> trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
> - xfs_bmbt_set_blockcount(ep,
> - new->br_startoff - PREV.br_startoff);
> + PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
> + xfs_iext_update_extent(ifp, *idx, &PREV);
> trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
>
> r[0] = *new;
> r[1].br_startoff = new_endoff;
> r[1].br_blockcount =
> - PREV.br_startoff + PREV.br_blockcount - new_endoff;
> + old.br_startoff + old.br_blockcount - new_endoff;
> r[1].br_startblock = new->br_startblock + new->br_blockcount;
> - r[1].br_state = oldext;
> + r[1].br_state = PREV.br_state;
>
> ++*idx;
> xfs_iext_insert(ip, *idx, 2, &r[0], state);
> @@ -2615,9 +2616,10 @@ xfs_bmap_add_extent_unwritten_real(
> rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
> else {
> rval = XFS_ILOG_CORE;
> - if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
> - PREV.br_startblock, PREV.br_blockcount,
> - &i)))
> + error = xfs_bmbt_lookup_eq(cur, old.br_startoff,
> + old.br_startblock, old.br_blockcount,
> + &i);
> + if (error)
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> /* new right extent - oldext */
> @@ -2627,8 +2629,6 @@ xfs_bmap_add_extent_unwritten_real(
> goto done;
> /* new left extent - oldext */
> cur->bc_rec.b = PREV;
> - cur->bc_rec.b.br_blockcount =
> - new->br_startoff - PREV.br_startoff;
> if ((error = xfs_btree_insert(cur, &i)))
> goto done;
> XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
> --
> 2.11.0
>
> --
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