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xfs: factor xfs_bmap_btalloc()
There are several different contexts xfs_bmap_btalloc() handles, and large chunks of the code execute independent allocation contexts. Try to untangle this mess a bit. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
This commit is contained in:
Dave Chinner
parent
74c36a8689
commit
8584332709
@ -3196,13 +3196,13 @@ xfs_bmap_select_minlen(
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}
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}
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STATIC int
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static int
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xfs_bmap_btalloc_select_lengths(
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struct xfs_bmalloca *ap,
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struct xfs_alloc_arg *args,
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xfs_extlen_t *blen)
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{
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struct xfs_mount *mp = ap->ip->i_mount;
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struct xfs_mount *mp = args->mp;
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struct xfs_perag *pag;
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xfs_agnumber_t agno, startag;
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int notinit = 0;
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@ -3216,7 +3216,7 @@ xfs_bmap_btalloc_select_lengths(
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}
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args->total = ap->total;
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startag = XFS_FSB_TO_AGNO(mp, args->fsbno);
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startag = XFS_FSB_TO_AGNO(mp, ap->blkno);
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if (startag == NULLAGNUMBER)
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startag = 0;
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@ -3258,7 +3258,7 @@ xfs_bmap_btalloc_filestreams(
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args->type = XFS_ALLOCTYPE_NEAR_BNO;
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args->total = ap->total;
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start_agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
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start_agno = XFS_FSB_TO_AGNO(mp, ap->blkno);
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if (start_agno == NULLAGNUMBER)
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start_agno = 0;
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@ -3496,19 +3496,212 @@ xfs_bmap_exact_minlen_extent_alloc(
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#endif
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STATIC int
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/*
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* If we are not low on available data blocks and we are allocating at
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* EOF, optimise allocation for contiguous file extension and/or stripe
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* alignment of the new extent.
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*
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* NOTE: ap->aeof is only set if the allocation length is >= the
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* stripe unit and the allocation offset is at the end of file.
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*/
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static int
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xfs_bmap_btalloc_at_eof(
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struct xfs_bmalloca *ap,
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struct xfs_alloc_arg *args,
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xfs_extlen_t blen,
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int stripe_align)
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{
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struct xfs_mount *mp = args->mp;
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xfs_alloctype_t atype;
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int error;
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/*
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* If there are already extents in the file, try an exact EOF block
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* allocation to extend the file as a contiguous extent. If that fails,
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* or it's the first allocation in a file, just try for a stripe aligned
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* allocation.
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*/
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if (ap->offset) {
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xfs_extlen_t nextminlen = 0;
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atype = args->type;
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args->type = XFS_ALLOCTYPE_THIS_BNO;
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args->alignment = 1;
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/*
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* Compute the minlen+alignment for the next case. Set slop so
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* that the value of minlen+alignment+slop doesn't go up between
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* the calls.
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*/
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if (blen > stripe_align && blen <= args->maxlen)
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nextminlen = blen - stripe_align;
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else
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nextminlen = args->minlen;
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if (nextminlen + stripe_align > args->minlen + 1)
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args->minalignslop = nextminlen + stripe_align -
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args->minlen - 1;
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else
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args->minalignslop = 0;
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args->pag = xfs_perag_get(mp, XFS_FSB_TO_AGNO(mp, args->fsbno));
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error = xfs_alloc_vextent_this_ag(args);
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xfs_perag_put(args->pag);
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if (error)
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return error;
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if (args->fsbno != NULLFSBLOCK)
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return 0;
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/*
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* Exact allocation failed. Reset to try an aligned allocation
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* according to the original allocation specification.
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*/
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args->pag = NULL;
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args->type = atype;
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args->fsbno = ap->blkno;
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args->alignment = stripe_align;
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args->minlen = nextminlen;
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args->minalignslop = 0;
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} else {
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args->alignment = stripe_align;
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atype = args->type;
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/*
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* Adjust minlen to try and preserve alignment if we
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* can't guarantee an aligned maxlen extent.
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*/
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if (blen > args->alignment &&
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blen <= args->maxlen + args->alignment)
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args->minlen = blen - args->alignment;
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args->minalignslop = 0;
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}
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error = xfs_alloc_vextent(args);
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if (error)
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return error;
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if (args->fsbno != NULLFSBLOCK)
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return 0;
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/*
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* Allocation failed, so turn return the allocation args to their
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* original non-aligned state so the caller can proceed on allocation
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* failure as if this function was never called.
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*/
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args->type = atype;
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args->fsbno = ap->blkno;
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args->alignment = 1;
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return 0;
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}
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static int
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xfs_bmap_btalloc_best_length(
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struct xfs_bmalloca *ap,
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struct xfs_alloc_arg *args,
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int stripe_align)
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{
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struct xfs_mount *mp = args->mp;
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xfs_extlen_t blen = 0;
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int error;
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/*
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* Determine the initial block number we will target for allocation.
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*/
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if ((ap->datatype & XFS_ALLOC_USERDATA) &&
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xfs_inode_is_filestream(ap->ip)) {
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xfs_agnumber_t agno = xfs_filestream_lookup_ag(ap->ip);
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if (agno == NULLAGNUMBER)
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agno = 0;
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ap->blkno = XFS_AGB_TO_FSB(mp, agno, 0);
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} else {
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ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
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}
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xfs_bmap_adjacent(ap);
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args->fsbno = ap->blkno;
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/*
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* Search for an allocation group with a single extent large enough for
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* the request. If one isn't found, then adjust the minimum allocation
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* size to the largest space found.
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*/
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if ((ap->datatype & XFS_ALLOC_USERDATA) &&
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xfs_inode_is_filestream(ap->ip))
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error = xfs_bmap_btalloc_filestreams(ap, args, &blen);
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else
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error = xfs_bmap_btalloc_select_lengths(ap, args, &blen);
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if (error)
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return error;
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/*
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* Don't attempt optimal EOF allocation if previous allocations barely
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* succeeded due to being near ENOSPC. It is highly unlikely we'll get
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* optimal or even aligned allocations in this case, so don't waste time
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* trying.
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*/
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if (ap->aeof && !(ap->tp->t_flags & XFS_TRANS_LOWMODE)) {
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error = xfs_bmap_btalloc_at_eof(ap, args, blen, stripe_align);
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if (error)
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return error;
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if (args->fsbno != NULLFSBLOCK)
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return 0;
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}
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error = xfs_alloc_vextent(args);
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if (error)
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return error;
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if (args->fsbno != NULLFSBLOCK)
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return 0;
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/*
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* Try a locality first full filesystem minimum length allocation whilst
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* still maintaining necessary total block reservation requirements.
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*/
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if (args->minlen > ap->minlen) {
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args->minlen = ap->minlen;
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args->type = XFS_ALLOCTYPE_START_BNO;
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args->fsbno = ap->blkno;
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error = xfs_alloc_vextent(args);
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if (error)
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return error;
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}
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if (args->fsbno != NULLFSBLOCK)
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return 0;
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/*
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* We are now critically low on space, so this is a last resort
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* allocation attempt: no reserve, no locality, blocking, minimum
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* length, full filesystem free space scan. We also indicate to future
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* allocations in this transaction that we are critically low on space
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* so they don't waste time on allocation modes that are unlikely to
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* succeed.
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*/
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args->fsbno = 0;
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args->type = XFS_ALLOCTYPE_FIRST_AG;
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args->total = ap->minlen;
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error = xfs_alloc_vextent(args);
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if (error)
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return error;
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ap->tp->t_flags |= XFS_TRANS_LOWMODE;
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return 0;
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}
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static int
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xfs_bmap_btalloc(
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struct xfs_bmalloca *ap)
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{
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struct xfs_mount *mp = ap->ip->i_mount;
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struct xfs_alloc_arg args = { .tp = ap->tp, .mp = mp };
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xfs_alloctype_t atype = 0;
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xfs_agnumber_t ag;
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struct xfs_alloc_arg args = {
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.tp = ap->tp,
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.mp = mp,
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.fsbno = NULLFSBLOCK,
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.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE,
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.minleft = ap->minleft,
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.wasdel = ap->wasdel,
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.resv = XFS_AG_RESV_NONE,
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.datatype = ap->datatype,
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.alignment = 1,
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.minalignslop = 0,
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};
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xfs_fileoff_t orig_offset;
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xfs_extlen_t orig_length;
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xfs_extlen_t blen;
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xfs_extlen_t nextminlen = 0;
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int isaligned = 0;
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int error;
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int stripe_align;
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@ -3518,148 +3711,14 @@ xfs_bmap_btalloc(
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stripe_align = xfs_bmap_compute_alignments(ap, &args);
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if ((ap->datatype & XFS_ALLOC_USERDATA) &&
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xfs_inode_is_filestream(ap->ip)) {
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ag = xfs_filestream_lookup_ag(ap->ip);
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ag = (ag != NULLAGNUMBER) ? ag : 0;
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ap->blkno = XFS_AGB_TO_FSB(mp, ag, 0);
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} else {
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ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
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}
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xfs_bmap_adjacent(ap);
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args.fsbno = ap->blkno;
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args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
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/* Trim the allocation back to the maximum an AG can fit. */
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args.maxlen = min(ap->length, mp->m_ag_max_usable);
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blen = 0;
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/*
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* Search for an allocation group with a single extent large
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* enough for the request. If one isn't found, then adjust
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* the minimum allocation size to the largest space found.
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*/
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if ((ap->datatype & XFS_ALLOC_USERDATA) &&
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xfs_inode_is_filestream(ap->ip))
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error = xfs_bmap_btalloc_filestreams(ap, &args, &blen);
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else
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error = xfs_bmap_btalloc_select_lengths(ap, &args, &blen);
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error = xfs_bmap_btalloc_best_length(ap, &args, stripe_align);
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if (error)
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return error;
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/*
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* If we are not low on available data blocks, and the underlying
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* logical volume manager is a stripe, and the file offset is zero then
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* try to allocate data blocks on stripe unit boundary. NOTE: ap->aeof
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* is only set if the allocation length is >= the stripe unit and the
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* allocation offset is at the end of file.
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*/
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if (!(ap->tp->t_flags & XFS_TRANS_LOWMODE) && ap->aeof) {
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if (!ap->offset) {
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args.alignment = stripe_align;
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atype = args.type;
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isaligned = 1;
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/*
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* Adjust minlen to try and preserve alignment if we
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* can't guarantee an aligned maxlen extent.
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*/
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if (blen > args.alignment &&
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blen <= args.maxlen + args.alignment)
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args.minlen = blen - args.alignment;
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args.minalignslop = 0;
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} else {
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/*
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* First try an exact bno allocation.
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* If it fails then do a near or start bno
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* allocation with alignment turned on.
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*/
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atype = args.type;
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args.type = XFS_ALLOCTYPE_THIS_BNO;
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args.alignment = 1;
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/*
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* Compute the minlen+alignment for the
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* next case. Set slop so that the value
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* of minlen+alignment+slop doesn't go up
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* between the calls.
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*/
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if (blen > stripe_align && blen <= args.maxlen)
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nextminlen = blen - stripe_align;
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else
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nextminlen = args.minlen;
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if (nextminlen + stripe_align > args.minlen + 1)
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args.minalignslop =
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nextminlen + stripe_align -
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args.minlen - 1;
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else
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args.minalignslop = 0;
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args.pag = xfs_perag_get(mp,
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XFS_FSB_TO_AGNO(mp, args.fsbno));
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error = xfs_alloc_vextent_this_ag(&args);
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xfs_perag_put(args.pag);
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if (error)
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return error;
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if (args.fsbno != NULLFSBLOCK)
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goto out_success;
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/*
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* Exact allocation failed. Now try with alignment
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* turned on.
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*/
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args.pag = NULL;
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args.type = atype;
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args.fsbno = ap->blkno;
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args.alignment = stripe_align;
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args.minlen = nextminlen;
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args.minalignslop = 0;
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isaligned = 1;
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}
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} else {
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args.alignment = 1;
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args.minalignslop = 0;
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}
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error = xfs_alloc_vextent(&args);
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if (error)
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return error;
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if (isaligned && args.fsbno == NULLFSBLOCK) {
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/*
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* allocation failed, so turn off alignment and
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* try again.
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*/
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args.type = atype;
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args.fsbno = ap->blkno;
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args.alignment = 0;
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if ((error = xfs_alloc_vextent(&args)))
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return error;
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}
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if (args.fsbno == NULLFSBLOCK &&
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args.minlen > ap->minlen) {
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args.minlen = ap->minlen;
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args.type = XFS_ALLOCTYPE_START_BNO;
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args.fsbno = ap->blkno;
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if ((error = xfs_alloc_vextent(&args)))
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return error;
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}
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if (args.fsbno == NULLFSBLOCK) {
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args.fsbno = 0;
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args.type = XFS_ALLOCTYPE_FIRST_AG;
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args.total = ap->minlen;
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if ((error = xfs_alloc_vextent(&args)))
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return error;
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ap->tp->t_flags |= XFS_TRANS_LOWMODE;
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}
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args.minleft = ap->minleft;
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args.wasdel = ap->wasdel;
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args.resv = XFS_AG_RESV_NONE;
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args.datatype = ap->datatype;
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if (args.fsbno != NULLFSBLOCK) {
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out_success:
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xfs_bmap_process_allocated_extent(ap, &args, orig_offset,
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orig_length);
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} else {
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