litmus-rt.git - The LITMUS^RT kernel.

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author	David Howells <dhowells@redhat.com>	2011-01-14 13:45:42 -0500
committer	Al Viro <viro@zeniv.linux.org.uk>	2011-01-15 20:07:34 -0500
commit	36d43a43761b004ad1879ac21471d8fc5f3157ec (patch)
tree	6cb6c6d978f4e58de7f9bf901707d6929f098345 /fs/nfs/callback_xdr.c
parent	d18610b0ce9eb48c60649d8fcbf68374c84349d3 (diff)

NFS: Use d_automount() rather than abusing follow_link()

Make NFS use the new d_automount() dentry operation rather than abusing follow_link() on directories. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Diffstat (limited to 'fs/nfs/callback_xdr.c')

0 files changed, 0 insertions, 0 deletions

/* * Functions related to segment and merge handling */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/scatterlist.h> #include "blk.h" static unsigned int __blk_recalc_rq_segments(struct request_queue *q, struct bio *bio) { struct bio_vec *bv, *bvprv = NULL; int cluster, i, high, highprv = 1; unsigned int seg_size, nr_phys_segs; struct bio *fbio, *bbio; if (!bio) return 0; fbio = bio; cluster = blk_queue_cluster(q); seg_size = 0; nr_phys_segs = 0; for_each_bio(bio) { bio_for_each_segment(bv, bio, i) { /* * the trick here is making sure that a high page is * never considered part of another segment, since that * might change with the bounce page. */ high = page_to_pfn(bv->bv_page) > queue_bounce_pfn(q); if (high || highprv) goto new_segment; if (cluster) { if (seg_size + bv->bv_len > queue_max_segment_size(q)) goto new_segment; if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv)) goto new_segment; if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv)) goto new_segment; seg_size += bv->bv_len; bvprv = bv; continue; } new_segment: if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size) fbio->bi_seg_front_size = seg_size; nr_phys_segs++; bvprv = bv; seg_size = bv->bv_len; highprv = high; } bbio = bio; } if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size) fbio->bi_seg_front_size = seg_size; if (seg_size > bbio->bi_seg_back_size) bbio->bi_seg_back_size = seg_size; return nr_phys_segs; } void blk_recalc_rq_segments(struct request *rq) { rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio); } void blk_recount_segments(struct request_queue *q, struct bio *bio) { struct bio *nxt = bio->bi_next; bio->bi_next = NULL; bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio); bio->bi_next = nxt; bio->bi_flags |= (1 << BIO_SEG_VALID); } EXPORT_SYMBOL(blk_recount_segments); static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, struct bio *nxt) { if (!blk_queue_cluster(q)) return 0; if (bio->bi_seg_back_size + nxt->bi_seg_front_size > queue_max_segment_size(q)) return 0; if (!bio_has_data(bio)) return 1; if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt))) return 0; /* * bio and nxt are contiguous in memory; check if the queue allows * these two to be merged into one */ if (BIO_SEG_BOUNDARY(q, bio, nxt)) return 1; return 0; } /* * map a request to scatterlist, return number of sg entries setup. Caller * must make sure sg can hold rq->nr_phys_segments entries */ int blk_rq_map_sg(struct request_queue *q, struct request *rq, struct scatterlist *sglist) { struct bio_vec *bvec, *bvprv; struct req_iterator iter; struct scatterlist *sg; int nsegs, cluster; nsegs = 0; cluster = blk_queue_cluster(q); /* * for each bio in rq */ bvprv = NULL; sg = NULL; rq_for_each_segment(bvec, rq, iter) { int nbytes = bvec->bv_len; if (bvprv && cluster) { if (sg->length + nbytes > queue_max_segment_size(q)) goto new_segment; if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) goto new_segment; if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec)) goto new_segment; sg->length += nbytes; } else { new_segment: if (!sg) sg = sglist; else { /* * If the driver previously mapped a shorter * list, we could see a termination bit * prematurely unless it fully inits the sg * table on each mapping. We KNOW that there * must be more entries here or the driver * would be buggy, so force clear the * termination bit to avoid doing a full * sg_init_table() in drivers for each command. */ sg->page_link &= ~0x02; sg = sg_next(sg); } sg_set_page(sg, bvec->bv_page, nbytes, bvec->bv_offset); nsegs++; } bvprv = bvec; } /* segments in rq */ if (unlikely(rq->cmd_flags & REQ_COPY_USER) && (blk_rq_bytes(rq) & q->dma_pad_mask)) { unsigned int pad_len = (q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1; sg->length += pad_len; rq->extra_len += pad_len; } if (q->dma_drain_size && q->dma_drain_needed(rq)) { if (rq->cmd_flags & REQ_WRITE) memset(q->dma_drain_buffer, 0, q->dma_drain_size); sg->page_link &= ~0x02; sg = sg_next(sg); sg_set_page(sg, virt_to_page(q->dma_drain_buffer), q->dma_drain_size, ((unsigned long)q->dma_drain_buffer) & (PAGE_SIZE - 1)); nsegs++; rq->extra_len += q->dma_drain_size; } if (sg) sg_mark_end(sg); return nsegs; } EXPORT_SYMBOL(blk_rq_map_sg); static inline int ll_new_hw_segment(struct request_queue *q, struct request *req, struct bio *bio) { int nr_phys_segs = bio_phys_segments(q, bio); if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q)) goto no_merge; if (bio_integrity(bio) && blk_integrity_merge_bio(q, req, bio)) goto no_merge; /* * This will form the start of a new hw segment. Bump both * counters. */ req->nr_phys_segments += nr_phys_segs; return 1; no_merge: req->cmd_flags |= REQ_NOMERGE; if (req == q->last_merge) q->last_merge = NULL; return 0; } int ll_back_merge_fn(struct request_queue *q, struct request *req, struct bio *bio) { unsigned short max_sectors; if (unlikely(req->cmd_type == REQ_TYPE_BLOCK_PC)) max_sectors = queue_max_hw_sectors(q); else max_sectors = queue_max_sectors(q); if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) { req->cmd_flags |= REQ_NOMERGE; if (req == q->last_merge) q->last_merge = NULL; return 0; } if (!bio_flagged(req->biotail, BIO_SEG_VALID)) blk_recount_segments(q, req->biotail); if (!bio_flagged(bio, BIO_SEG_VALID)) blk_recount_segments(q, bio); return ll_new_hw_segment(q, req, bio); } int ll_front_merge_fn(struct request_queue *q, struct request *req, struct bio *bio) { unsigned short max_sectors; if (unlikely(req->cmd_type == REQ_TYPE_BLOCK_PC)) max_sectors = queue_max_hw_sectors(q); else max_sectors = queue_max_sectors(q); if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) { req->cmd_flags |= REQ_NOMERGE; if (req == q->last_merge) q->last_merge = NULL; return 0; } if (!bio_flagged(bio, BIO_SEG_VALID)) blk_recount_segments(q, bio); if (!bio_flagged(req->bio, BIO_SEG_VALID)) blk_recount_segments(q, req->bio); return ll_new_hw_segment(q, req, bio); } static int ll_merge_requests_fn(struct request_queue *q, struct request *req, struct request *next) { int total_phys_segments; unsigned int seg_size = req->biotail->bi_seg_back_size + next->bio->bi_seg_front_size; /* * First check if the either of the requests are re-queued * requests. Can't merge them if they are. */


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