diff options
Diffstat (limited to 'kernel/fs/nfs/blocklayout/blocklayout.c')
| -rw-r--r-- | kernel/fs/nfs/blocklayout/blocklayout.c | 928 |
1 files changed, 928 insertions, 0 deletions
diff --git a/kernel/fs/nfs/blocklayout/blocklayout.c b/kernel/fs/nfs/blocklayout/blocklayout.c new file mode 100644 index 000000000..d2554fe14 --- /dev/null +++ b/kernel/fs/nfs/blocklayout/blocklayout.c @@ -0,0 +1,928 @@ +/* + * linux/fs/nfs/blocklayout/blocklayout.c + * + * Module for the NFSv4.1 pNFS block layout driver. + * + * Copyright (c) 2006 The Regents of the University of Michigan. + * All rights reserved. + * + * Andy Adamson <andros@citi.umich.edu> + * Fred Isaman <iisaman@umich.edu> + * + * permission is granted to use, copy, create derivative works and + * redistribute this software and such derivative works for any purpose, + * so long as the name of the university of michigan is not used in + * any advertising or publicity pertaining to the use or distribution + * of this software without specific, written prior authorization. if + * the above copyright notice or any other identification of the + * university of michigan is included in any copy of any portion of + * this software, then the disclaimer below must also be included. + * + * this software is provided as is, without representation from the + * university of michigan as to its fitness for any purpose, and without + * warranty by the university of michigan of any kind, either express + * or implied, including without limitation the implied warranties of + * merchantability and fitness for a particular purpose. the regents + * of the university of michigan shall not be liable for any damages, + * including special, indirect, incidental, or consequential damages, + * with respect to any claim arising out or in connection with the use + * 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 <linux/prefetch.h> +#include <linux/pagevec.h> + +#include "../pnfs.h" +#include "../nfs4session.h" +#include "../internal.h" +#include "blocklayout.h" + +#define NFSDBG_FACILITY NFSDBG_PNFS_LD + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>"); +MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver"); + +static bool is_hole(struct pnfs_block_extent *be) +{ + switch (be->be_state) { + case PNFS_BLOCK_NONE_DATA: + return true; + case PNFS_BLOCK_INVALID_DATA: + return be->be_tag ? false : true; + default: + return false; + } +} + +/* 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; + 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_iter.bi_size, + (unsigned long long)bio->bi_iter.bi_sector); + submit_bio(rw, bio); + } + return NULL; +} + +static struct bio * +bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector, + void (*end_io)(struct bio *, int err), struct parallel_io *par) +{ + struct bio *bio; + + npg = min(npg, BIO_MAX_PAGES); + bio = bio_alloc(GFP_NOIO, npg); + if (!bio && (current->flags & PF_MEMALLOC)) { + while (!bio && (npg /= 2)) + bio = bio_alloc(GFP_NOIO, npg); + } + + if (bio) { + bio->bi_iter.bi_sector = disk_sector; + bio->bi_bdev = bdev; + bio->bi_end_io = end_io; + bio->bi_private = par; + } + return bio; +} + +static struct bio * +do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect, + struct page *page, struct pnfs_block_dev_map *map, + struct pnfs_block_extent *be, + void (*end_io)(struct bio *, int err), + struct parallel_io *par, unsigned int offset, int *len) +{ + struct pnfs_block_dev *dev = + container_of(be->be_device, struct pnfs_block_dev, node); + u64 disk_addr, end; + + dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__, + npg, rw, (unsigned long long)isect, offset, *len); + + /* translate to device offset */ + isect += be->be_v_offset; + isect -= be->be_f_offset; + + /* translate to physical disk offset */ + disk_addr = (u64)isect << SECTOR_SHIFT; + if (disk_addr < map->start || disk_addr >= map->start + map->len) { + if (!dev->map(dev, disk_addr, map)) + return ERR_PTR(-EIO); + bio = bl_submit_bio(rw, bio); + } + disk_addr += map->disk_offset; + disk_addr -= map->start; + + /* limit length to what the device mapping allows */ + end = disk_addr + *len; + if (end >= map->start + map->len) + *len = map->start + map->len - disk_addr; + +retry: + if (!bio) { + bio = bl_alloc_init_bio(npg, map->bdev, + disk_addr >> SECTOR_SHIFT, end_io, par); + if (!bio) + return ERR_PTR(-ENOMEM); + } + if (bio_add_page(bio, page, *len, offset) < *len) { + bio = bl_submit_bio(rw, bio); + goto retry; + } + return bio; +} + +static void bl_end_io_read(struct bio *bio, int err) +{ + struct parallel_io *par = bio->bi_private; + + if (err) { + struct nfs_pgio_header *header = par->data; + + if (!header->pnfs_error) + header->pnfs_error = -EIO; + pnfs_set_lo_fail(header->lseg); + } + + bio_put(bio); + put_parallel(par); +} + +static void bl_read_cleanup(struct work_struct *work) +{ + struct rpc_task *task; + struct nfs_pgio_header *hdr; + dprintk("%s enter\n", __func__); + task = container_of(work, struct rpc_task, u.tk_work); + hdr = container_of(task, struct nfs_pgio_header, task); + pnfs_ld_read_done(hdr); +} + +static void +bl_end_par_io_read(void *data) +{ + struct nfs_pgio_header *hdr = data; + + hdr->task.tk_status = hdr->pnfs_error; + INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup); + schedule_work(&hdr->task.u.tk_work); +} + +static enum pnfs_try_status +bl_read_pagelist(struct nfs_pgio_header *header) +{ + struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg); + struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 }; + struct bio *bio = NULL; + struct pnfs_block_extent be; + sector_t isect, extent_length = 0; + struct parallel_io *par; + loff_t f_offset = header->args.offset; + size_t bytes_left = header->args.count; + unsigned int pg_offset, pg_len; + struct page **pages = header->args.pages; + int pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT; + const bool is_dio = (header->dreq != NULL); + struct blk_plug plug; + int i; + + dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__, + header->page_array.npages, f_offset, + (unsigned int)header->args.count); + + par = alloc_parallel(header); + if (!par) + return PNFS_NOT_ATTEMPTED; + par->pnfs_callback = bl_end_par_io_read; + + blk_start_plug(&plug); + + isect = (sector_t) (f_offset >> SECTOR_SHIFT); + /* Code assumes extents are page-aligned */ + for (i = pg_index; i < header->page_array.npages; i++) { + if (extent_length <= 0) { + /* We've used up the previous extent */ + bio = bl_submit_bio(READ, bio); + + /* Get the next one */ + if (!ext_tree_lookup(bl, isect, &be, false)) { + header->pnfs_error = -EIO; + goto out; + } + extent_length = be.be_length - (isect - be.be_f_offset); + } + + pg_offset = f_offset & ~PAGE_CACHE_MASK; + if (is_dio) { + if (pg_offset + bytes_left > PAGE_CACHE_SIZE) + pg_len = PAGE_CACHE_SIZE - pg_offset; + else + pg_len = bytes_left; + } else { + BUG_ON(pg_offset != 0); + pg_len = PAGE_CACHE_SIZE; + } + + isect += (pg_offset >> SECTOR_SHIFT); + extent_length -= (pg_offset >> SECTOR_SHIFT); + + if (is_hole(&be)) { + 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], pg_offset, pg_len); + + /* invalidate map */ + map.start = NFS4_MAX_UINT64; + } else { + bio = do_add_page_to_bio(bio, + header->page_array.npages - i, + READ, + isect, pages[i], &map, &be, + bl_end_io_read, par, + pg_offset, &pg_len); + if (IS_ERR(bio)) { + header->pnfs_error = PTR_ERR(bio); + bio = NULL; + goto out; + } + } + isect += (pg_len >> SECTOR_SHIFT); + extent_length -= (pg_len >> SECTOR_SHIFT); + f_offset += pg_len; + bytes_left -= pg_len; + } + if ((isect << SECTOR_SHIFT) >= header->inode->i_size) { + header->res.eof = 1; + header->res.count = header->inode->i_size - header->args.offset; + } else { + header->res.count = (isect << SECTOR_SHIFT) - header->args.offset; + } +out: + bl_submit_bio(READ, bio); + blk_finish_plug(&plug); + put_parallel(par); + return PNFS_ATTEMPTED; +} + +static void bl_end_io_write(struct bio *bio, int err) +{ + struct parallel_io *par = bio->bi_private; + const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); + struct nfs_pgio_header *header = par->data; + + if (!uptodate) { + if (!header->pnfs_error) + header->pnfs_error = -EIO; + pnfs_set_lo_fail(header->lseg); + } + bio_put(bio); + put_parallel(par); +} + +/* Function scheduled for call during bl_end_par_io_write, + * it marks sectors as written and extends the commitlist. + */ +static void bl_write_cleanup(struct work_struct *work) +{ + struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work); + struct nfs_pgio_header *hdr = + container_of(task, struct nfs_pgio_header, task); + + dprintk("%s enter\n", __func__); + + if (likely(!hdr->pnfs_error)) { + struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg); + u64 start = hdr->args.offset & (loff_t)PAGE_CACHE_MASK; + u64 end = (hdr->args.offset + hdr->args.count + + PAGE_CACHE_SIZE - 1) & (loff_t)PAGE_CACHE_MASK; + + ext_tree_mark_written(bl, start >> SECTOR_SHIFT, + (end - start) >> SECTOR_SHIFT); + } + + pnfs_ld_write_done(hdr); +} + +/* Called when last of bios associated with a bl_write_pagelist call finishes */ +static void bl_end_par_io_write(void *data) +{ + struct nfs_pgio_header *hdr = data; + + hdr->task.tk_status = hdr->pnfs_error; + hdr->verf.committed = NFS_FILE_SYNC; + INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup); + schedule_work(&hdr->task.u.tk_work); +} + +static enum pnfs_try_status +bl_write_pagelist(struct nfs_pgio_header *header, int sync) +{ + struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg); + struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 }; + struct bio *bio = NULL; + struct pnfs_block_extent be; + sector_t isect, extent_length = 0; + struct parallel_io *par = NULL; + loff_t offset = header->args.offset; + size_t count = header->args.count; + struct page **pages = header->args.pages; + int pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT; + unsigned int pg_len; + struct blk_plug plug; + int i; + + dprintk("%s enter, %Zu@%lld\n", __func__, count, offset); + + /* At this point, header->page_aray is a (sequential) list of nfs_pages. + * We want to write each, and if there is an error set pnfs_error + * to have it redone using nfs. + */ + par = alloc_parallel(header); + if (!par) + return PNFS_NOT_ATTEMPTED; + par->pnfs_callback = bl_end_par_io_write; + + blk_start_plug(&plug); + + /* we always write out the whole page */ + offset = offset & (loff_t)PAGE_CACHE_MASK; + isect = offset >> SECTOR_SHIFT; + + for (i = pg_index; i < header->page_array.npages; i++) { + if (extent_length <= 0) { + /* We've used up the previous extent */ + bio = bl_submit_bio(WRITE, bio); + /* Get the next one */ + if (!ext_tree_lookup(bl, isect, &be, true)) { + header->pnfs_error = -EINVAL; + goto out; + } + + extent_length = be.be_length - (isect - be.be_f_offset); + } + + pg_len = PAGE_CACHE_SIZE; + bio = do_add_page_to_bio(bio, header->page_array.npages - i, + WRITE, isect, pages[i], &map, &be, + bl_end_io_write, par, + 0, &pg_len); + if (IS_ERR(bio)) { + header->pnfs_error = PTR_ERR(bio); + bio = NULL; + goto out; + } + + offset += pg_len; + count -= pg_len; + isect += (pg_len >> SECTOR_SHIFT); + extent_length -= (pg_len >> SECTOR_SHIFT); + } + + header->res.count = header->args.count; +out: + bl_submit_bio(WRITE, bio); + blk_finish_plug(&plug); + put_parallel(par); + return PNFS_ATTEMPTED; +} + +static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo) +{ + struct pnfs_block_layout *bl = BLK_LO2EXT(lo); + int err; + + dprintk("%s enter\n", __func__); + + err = ext_tree_remove(bl, true, 0, LLONG_MAX); + WARN_ON(err); + + kfree(bl); +} + +static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode, + gfp_t gfp_flags) +{ + struct pnfs_block_layout *bl; + + dprintk("%s enter\n", __func__); + bl = kzalloc(sizeof(*bl), gfp_flags); + if (!bl) + return NULL; + + bl->bl_ext_rw = RB_ROOT; + bl->bl_ext_ro = RB_ROOT; + spin_lock_init(&bl->bl_ext_lock); + + return &bl->bl_layout; +} + +static void bl_free_lseg(struct pnfs_layout_segment *lseg) +{ + dprintk("%s enter\n", __func__); + kfree(lseg); +} + +/* Tracks info needed to ensure extents in layout obey constraints of spec */ +struct layout_verification { + u32 mode; /* R or RW */ + u64 start; /* Expected start of next non-COW extent */ + u64 inval; /* Start of INVAL coverage */ + u64 cowread; /* End of COW read coverage */ +}; + +/* Verify the extent meets the layout requirements of the pnfs-block draft, + * section 2.3.1. + */ +static int verify_extent(struct pnfs_block_extent *be, + struct layout_verification *lv) +{ + if (lv->mode == IOMODE_READ) { + if (be->be_state == PNFS_BLOCK_READWRITE_DATA || + be->be_state == PNFS_BLOCK_INVALID_DATA) + return -EIO; + if (be->be_f_offset != lv->start) + return -EIO; + lv->start += be->be_length; + return 0; + } + /* lv->mode == IOMODE_RW */ + if (be->be_state == PNFS_BLOCK_READWRITE_DATA) { + if (be->be_f_offset != lv->start) + return -EIO; + if (lv->cowread > lv->start) + return -EIO; + lv->start += be->be_length; + lv->inval = lv->start; + return 0; + } else if (be->be_state == PNFS_BLOCK_INVALID_DATA) { + if (be->be_f_offset != lv->start) + return -EIO; + lv->start += be->be_length; + return 0; + } else if (be->be_state == PNFS_BLOCK_READ_DATA) { + if (be->be_f_offset > lv->start) + return -EIO; + if (be->be_f_offset < lv->inval) + return -EIO; + if (be->be_f_offset < lv->cowread) + return -EIO; + /* It looks like you might want to min this with lv->start, + * but you really don't. + */ + lv->inval = lv->inval + be->be_length; + lv->cowread = be->be_f_offset + be->be_length; + return 0; + } else + return -EIO; +} + +static int decode_sector_number(__be32 **rp, sector_t *sp) +{ + uint64_t s; + + *rp = xdr_decode_hyper(*rp, &s); + if (s & 0x1ff) { + printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__); + return -1; + } + *sp = s >> SECTOR_SHIFT; + return 0; +} + +static int +bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo, + struct layout_verification *lv, struct list_head *extents, + gfp_t gfp_mask) +{ + struct pnfs_block_extent *be; + struct nfs4_deviceid id; + int error; + __be32 *p; + + p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE); + if (!p) + return -EIO; + + be = kzalloc(sizeof(*be), GFP_NOFS); + if (!be) + return -ENOMEM; + + memcpy(&id, p, NFS4_DEVICEID4_SIZE); + p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE); + + error = -EIO; + be->be_device = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id, + lo->plh_lc_cred, gfp_mask); + if (!be->be_device) + goto out_free_be; + + /* + * The next three values are read in as bytes, but stored in the + * extent structure in 512-byte granularity. + */ + if (decode_sector_number(&p, &be->be_f_offset) < 0) + goto out_put_deviceid; + if (decode_sector_number(&p, &be->be_length) < 0) + goto out_put_deviceid; + if (decode_sector_number(&p, &be->be_v_offset) < 0) + goto out_put_deviceid; + be->be_state = be32_to_cpup(p++); + + error = verify_extent(be, lv); + if (error) { + dprintk("%s: extent verification failed\n", __func__); + goto out_put_deviceid; + } + + list_add_tail(&be->be_list, extents); + return 0; + +out_put_deviceid: + nfs4_put_deviceid_node(be->be_device); +out_free_be: + kfree(be); + return error; +} + +static struct pnfs_layout_segment * +bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr, + gfp_t gfp_mask) +{ + struct layout_verification lv = { + .mode = lgr->range.iomode, + .start = lgr->range.offset >> SECTOR_SHIFT, + .inval = lgr->range.offset >> SECTOR_SHIFT, + .cowread = lgr->range.offset >> SECTOR_SHIFT, + }; + struct pnfs_block_layout *bl = BLK_LO2EXT(lo); + struct pnfs_layout_segment *lseg; + struct xdr_buf buf; + struct xdr_stream xdr; + struct page *scratch; + int status, i; + uint32_t count; + __be32 *p; + LIST_HEAD(extents); + + dprintk("---> %s\n", __func__); + + lseg = kzalloc(sizeof(*lseg), gfp_mask); + if (!lseg) + return ERR_PTR(-ENOMEM); + + status = -ENOMEM; + scratch = alloc_page(gfp_mask); + if (!scratch) + goto out; + + xdr_init_decode_pages(&xdr, &buf, + lgr->layoutp->pages, lgr->layoutp->len); + xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE); + + status = -EIO; + p = xdr_inline_decode(&xdr, 4); + if (unlikely(!p)) + goto out_free_scratch; + + count = be32_to_cpup(p++); + dprintk("%s: number of extents %d\n", __func__, count); + + /* + * Decode individual extents, putting them in temporary staging area + * until whole layout is decoded to make error recovery easier. + */ + for (i = 0; i < count; i++) { + status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask); + if (status) + goto process_extents; + } + + if (lgr->range.offset + lgr->range.length != + lv.start << SECTOR_SHIFT) { + dprintk("%s Final length mismatch\n", __func__); + status = -EIO; + goto process_extents; + } + + if (lv.start < lv.cowread) { + dprintk("%s Final uncovered COW extent\n", __func__); + status = -EIO; + } + +process_extents: + while (!list_empty(&extents)) { + struct pnfs_block_extent *be = + list_first_entry(&extents, struct pnfs_block_extent, + be_list); + list_del(&be->be_list); + + if (!status) + status = ext_tree_insert(bl, be); + + if (status) { + nfs4_put_deviceid_node(be->be_device); + kfree(be); + } + } + +out_free_scratch: + __free_page(scratch); +out: + dprintk("%s returns %d\n", __func__, status); + if (status) { + kfree(lseg); + return ERR_PTR(status); + } + return lseg; +} + +static void +bl_return_range(struct pnfs_layout_hdr *lo, + struct pnfs_layout_range *range) +{ + struct pnfs_block_layout *bl = BLK_LO2EXT(lo); + sector_t offset = range->offset >> SECTOR_SHIFT, end; + + if (range->offset % 8) { + dprintk("%s: offset %lld not block size aligned\n", + __func__, range->offset); + return; + } + + if (range->length != NFS4_MAX_UINT64) { + if (range->length % 8) { + dprintk("%s: length %lld not block size aligned\n", + __func__, range->length); + return; + } + + end = offset + (range->length >> SECTOR_SHIFT); + } else { + end = round_down(NFS4_MAX_UINT64, PAGE_SIZE); + } + + ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end); +} + +static int +bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg) +{ + return ext_tree_prepare_commit(arg); +} + +static void +bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata) +{ + ext_tree_mark_committed(&lcdata->args, lcdata->res.status); +} + +static int +bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh) +{ + dprintk("%s enter\n", __func__); + + if (server->pnfs_blksize == 0) { + dprintk("%s Server did not return blksize\n", __func__); + return -EINVAL; + } + if (server->pnfs_blksize > PAGE_SIZE) { + printk(KERN_ERR "%s: pNFS blksize %d not supported.\n", + __func__, server->pnfs_blksize); + return -EINVAL; + } + + return 0; +} + +static bool +is_aligned_req(struct nfs_pageio_descriptor *pgio, + struct nfs_page *req, unsigned int alignment) +{ + /* + * Always accept buffered writes, higher layers take care of the + * right alignment. + */ + if (pgio->pg_dreq == NULL) + return true; + + if (!IS_ALIGNED(req->wb_offset, alignment)) + return false; + + if (IS_ALIGNED(req->wb_bytes, alignment)) + return true; + + if (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode)) { + /* + * If the write goes up to the inode size, just write + * the full page. Data past the inode size is + * guaranteed to be zeroed by the higher level client + * code, and this behaviour is mandated by RFC 5663 + * section 2.3.2. + */ + return true; + } + + return false; +} + +static void +bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) +{ + if (!is_aligned_req(pgio, req, SECTOR_SIZE)) { + nfs_pageio_reset_read_mds(pgio); + return; + } + + pnfs_generic_pg_init_read(pgio, req); +} + +/* + * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number + * of bytes (maximum @req->wb_bytes) that can be coalesced. + */ +static size_t +bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, + struct nfs_page *req) +{ + if (!is_aligned_req(pgio, req, SECTOR_SIZE)) + return 0; + return pnfs_generic_pg_test(pgio, prev, req); +} + +/* + * Return the number of contiguous bytes for a given inode + * starting at page frame idx. + */ +static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx) +{ + struct address_space *mapping = inode->i_mapping; + pgoff_t end; + + /* Optimize common case that writes from 0 to end of file */ + end = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE); + if (end != inode->i_mapping->nrpages) { + rcu_read_lock(); + end = page_cache_next_hole(mapping, idx + 1, ULONG_MAX); + rcu_read_unlock(); + } + + if (!end) + return i_size_read(inode) - (idx << PAGE_CACHE_SHIFT); + else + return (end - idx) << PAGE_CACHE_SHIFT; +} + +static void +bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) +{ + u64 wb_size; + + if (!is_aligned_req(pgio, req, PAGE_SIZE)) { + nfs_pageio_reset_write_mds(pgio); + return; + } + + if (pgio->pg_dreq == NULL) + wb_size = pnfs_num_cont_bytes(pgio->pg_inode, + req->wb_index); + else + wb_size = nfs_dreq_bytes_left(pgio->pg_dreq); + + pnfs_generic_pg_init_write(pgio, req, wb_size); +} + +/* + * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number + * of bytes (maximum @req->wb_bytes) that can be coalesced. + */ +static size_t +bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, + struct nfs_page *req) +{ + if (!is_aligned_req(pgio, req, PAGE_SIZE)) + return 0; + return pnfs_generic_pg_test(pgio, prev, req); +} + +static const struct nfs_pageio_ops bl_pg_read_ops = { + .pg_init = bl_pg_init_read, + .pg_test = bl_pg_test_read, + .pg_doio = pnfs_generic_pg_readpages, + .pg_cleanup = pnfs_generic_pg_cleanup, +}; + +static const struct nfs_pageio_ops bl_pg_write_ops = { + .pg_init = bl_pg_init_write, + .pg_test = bl_pg_test_write, + .pg_doio = pnfs_generic_pg_writepages, + .pg_cleanup = pnfs_generic_pg_cleanup, +}; + +static struct pnfs_layoutdriver_type blocklayout_type = { + .id = LAYOUT_BLOCK_VOLUME, + .name = "LAYOUT_BLOCK_VOLUME", + .owner = THIS_MODULE, + .flags = PNFS_LAYOUTRET_ON_SETATTR | + PNFS_READ_WHOLE_PAGE, + .read_pagelist = bl_read_pagelist, + .write_pagelist = bl_write_pagelist, + .alloc_layout_hdr = bl_alloc_layout_hdr, + .free_layout_hdr = bl_free_layout_hdr, + .alloc_lseg = bl_alloc_lseg, + .free_lseg = bl_free_lseg, + .return_range = bl_return_range, + .prepare_layoutcommit = bl_prepare_layoutcommit, + .cleanup_layoutcommit = bl_cleanup_layoutcommit, + .set_layoutdriver = bl_set_layoutdriver, + .alloc_deviceid_node = bl_alloc_deviceid_node, + .free_deviceid_node = bl_free_deviceid_node, + .pg_read_ops = &bl_pg_read_ops, + .pg_write_ops = &bl_pg_write_ops, + .sync = pnfs_generic_sync, +}; + +static int __init nfs4blocklayout_init(void) +{ + int ret; + + dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__); + + ret = pnfs_register_layoutdriver(&blocklayout_type); + if (ret) + goto out; + ret = bl_init_pipefs(); + if (ret) + goto out_unregister; + return 0; + +out_unregister: + pnfs_unregister_layoutdriver(&blocklayout_type); +out: + return ret; +} + +static void __exit nfs4blocklayout_exit(void) +{ + dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n", + __func__); + + bl_cleanup_pipefs(); + pnfs_unregister_layoutdriver(&blocklayout_type); +} + +MODULE_ALIAS("nfs-layouttype4-3"); + +module_init(nfs4blocklayout_init); +module_exit(nfs4blocklayout_exit); |