diff options
| -rw-r--r-- | fs/nfs/blocklayout/blocklayout.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index 6c1bafb8920b..facb5ba21204 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -29,10 +29,12 @@ * of the software, even if it has been or is hereafter advised of the * possibility of such damages. */ + #include <linux/module.h> #include <linux/init.h> #include <linux/mount.h> #include <linux/namei.h> +#include <linux/bio.h> /* struct bio */ #include "blocklayout.h" @@ -45,9 +47,272 @@ MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver"); struct dentry *bl_device_pipe; wait_queue_head_t bl_wq; +static void print_page(struct page *page) +{ + dprintk("PRINTPAGE page %p\n", page); + dprintk(" PagePrivate %d\n", PagePrivate(page)); + dprintk(" PageUptodate %d\n", PageUptodate(page)); + dprintk(" PageError %d\n", PageError(page)); + dprintk(" PageDirty %d\n", PageDirty(page)); + dprintk(" PageReferenced %d\n", PageReferenced(page)); + dprintk(" PageLocked %d\n", PageLocked(page)); + dprintk(" PageWriteback %d\n", PageWriteback(page)); + dprintk(" PageMappedToDisk %d\n", PageMappedToDisk(page)); + dprintk("\n"); +} + +/* Given the be associated with isect, determine if page data needs to be + * initialized. + */ +static int is_hole(struct pnfs_block_extent *be, sector_t isect) +{ + if (be->be_state == PNFS_BLOCK_NONE_DATA) + return 1; + else if (be->be_state != PNFS_BLOCK_INVALID_DATA) + return 0; + else + return !bl_is_sector_init(be->be_inval, isect); +} + +/* The data we are handed might be spread across several bios. We need + * to track when the last one is finished. + */ +struct parallel_io { + struct kref refcnt; + struct rpc_call_ops call_ops; + void (*pnfs_callback) (void *data); + void *data; +}; + +static inline struct parallel_io *alloc_parallel(void *data) +{ + struct parallel_io *rv; + + rv = kmalloc(sizeof(*rv), GFP_NOFS); + if (rv) { + rv->data = data; + kref_init(&rv->refcnt); + } + return rv; +} + +static inline void get_parallel(struct parallel_io *p) +{ + kref_get(&p->refcnt); +} + +static void destroy_parallel(struct kref *kref) +{ + struct parallel_io *p = container_of(kref, struct parallel_io, refcnt); + + dprintk("%s enter\n", __func__); + p->pnfs_callback(p->data); + kfree(p); +} + +static inline void put_parallel(struct parallel_io *p) +{ + kref_put(&p->refcnt, destroy_parallel); +} + +static struct bio * +bl_submit_bio(int rw, struct bio *bio) +{ + if (bio) { + get_parallel(bio->bi_private); + dprintk("%s submitting %s bio %u@%llu\n", __func__, + rw == READ ? "read" : "write", + bio->bi_size, (unsigned long long)bio->bi_sector); + submit_bio(rw, bio); + } + return NULL; +} + +static struct bio *bl_alloc_init_bio(int npg, sector_t isect, + struct pnfs_block_extent *be, + void (*end_io)(struct bio *, int err), + struct parallel_io *par) +{ + struct bio *bio; + + bio = bio_alloc(GFP_NOIO, npg); + if (!bio) + return NULL; + + bio->bi_sector = isect - be->be_f_offset + be->be_v_offset; + bio->bi_bdev = be->be_mdev; + bio->bi_end_io = end_io; + bio->bi_private = par; + return bio; +} + +static struct bio *bl_add_page_to_bio(struct bio *bio, int npg, int rw, + sector_t isect, struct page *page, + struct pnfs_block_extent *be, + void (*end_io)(struct bio *, int err), + struct parallel_io *par) +{ +retry: + if (!bio) { + bio = bl_alloc_init_bio(npg, isect, be, end_io, par); + if (!bio) + return ERR_PTR(-ENOMEM); + } + if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) { + bio = bl_submit_bio(rw, bio); + goto retry; + } + return bio; +} + +static void bl_set_lo_fail(struct pnfs_layout_segment *lseg) +{ + if (lseg->pls_range.iomode == IOMODE_RW) { + dprintk("%s Setting layout IOMODE_RW fail bit\n", __func__); + set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags); + } else { + dprintk("%s Setting layout IOMODE_READ fail bit\n", __func__); + set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags); + } +} + +/* This is basically copied from mpage_end_io_read */ +static void bl_end_io_read(struct bio *bio, int err) +{ + struct parallel_io *par = bio->bi_private; + const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); + struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; + struct nfs_read_data *rdata = (struct nfs_read_data *)par->data; + + do { + struct page *page = bvec->bv_page; + + if (--bvec >= bio->bi_io_vec) + prefetchw(&bvec->bv_page->flags); + if (uptodate) + SetPageUptodate(page); + } while (bvec >= bio->bi_io_vec); + if (!uptodate) { + if (!rdata->pnfs_error) + rdata->pnfs_error = -EIO; + bl_set_lo_fail(rdata->lseg); + } + bio_put(bio); + put_parallel(par); +} + +static void bl_read_cleanup(struct work_struct *work) +{ + struct rpc_task *task; + struct nfs_read_data *rdata; + dprintk("%s enter\n", __func__); + task = container_of(work, struct rpc_task, u.tk_work); + rdata = container_of(task, struct nfs_read_data, task); + pnfs_ld_read_done(rdata); +} + +static void +bl_end_par_io_read(void *data) +{ + struct nfs_read_data *rdata = data; + + INIT_WORK(&rdata->task.u.tk_work, bl_read_cleanup); + schedule_work(&rdata->task.u.tk_work); +} + +/* We don't want normal .rpc_call_done callback used, so we replace it + * with this stub. + */ +static void bl_rpc_do_nothing(struct rpc_task *task, void *calldata) +{ + return; +} + static enum pnfs_try_status bl_read_pagelist(struct nfs_read_data *rdata) { + int i, hole; + struct bio *bio = NULL; + struct pnfs_block_extent *be = NULL, *cow_read = NULL; + sector_t isect, extent_length = 0; + struct parallel_io *par; + loff_t f_offset = rdata->args.offset; + size_t count = rdata->args.count; + struct page **pages = rdata->args.pages; + int pg_index = rdata->args.pgbase >> PAGE_CACHE_SHIFT; + + dprintk("%s enter nr_pages %u offset %lld count %Zd\n", __func__, + rdata->npages, f_offset, count); + + par = alloc_parallel(rdata); + if (!par) + goto use_mds; + par->call_ops = *rdata->mds_ops; + par->call_ops.rpc_call_done = bl_rpc_do_nothing; + par->pnfs_callback = bl_end_par_io_read; + /* At this point, we can no longer jump to use_mds */ + + isect = (sector_t) (f_offset >> SECTOR_SHIFT); + /* Code assumes extents are page-aligned */ + for (i = pg_index; i < rdata->npages; i++) { + if (!extent_length) { + /* We've used up the previous extent */ + bl_put_extent(be); + bl_put_extent(cow_read); + bio = bl_submit_bio(READ, bio); + /* Get the next one */ + be = bl_find_get_extent(BLK_LSEG2EXT(rdata->lseg), + isect, &cow_read); + if (!be) { + rdata->pnfs_error = -EIO; + goto out; + } + extent_length = be->be_length - + (isect - be->be_f_offset); + if (cow_read) { + sector_t cow_length = cow_read->be_length - + (isect - cow_read->be_f_offset); + extent_length = min(extent_length, cow_length); + } + } + hole = is_hole(be, isect); + if (hole && !cow_read) { + bio = bl_submit_bio(READ, bio); + /* Fill hole w/ zeroes w/o accessing device */ + dprintk("%s Zeroing page for hole\n", __func__); + zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE); + print_page(pages[i]); + SetPageUptodate(pages[i]); + } else { + struct pnfs_block_extent *be_read; + + be_read = (hole && cow_read) ? cow_read : be; + bio = bl_add_page_to_bio(bio, rdata->npages - i, READ, + isect, pages[i], be_read, + bl_end_io_read, par); + if (IS_ERR(bio)) { + rdata->pnfs_error = PTR_ERR(bio); + goto out; + } + } + isect += PAGE_CACHE_SECTORS; + extent_length -= PAGE_CACHE_SECTORS; + } + if ((isect << SECTOR_SHIFT) >= rdata->inode->i_size) { + rdata->res.eof = 1; + rdata->res.count = rdata->inode->i_size - f_offset; + } else { + rdata->res.count = (isect << SECTOR_SHIFT) - f_offset; + } +out: + bl_put_extent(be); + bl_put_extent(cow_read); + bl_submit_bio(READ, bio); + put_parallel(par); + return PNFS_ATTEMPTED; + + use_mds: + dprintk("Giving up and using normal NFS\n"); return PNFS_NOT_ATTEMPTED; } |