| /* |
| * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| * |
| * This copyrighted material is made available to anyone wishing to use, |
| * modify, copy, or redistribute it subject to the terms and conditions |
| * of the GNU General Public License version 2. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/completion.h> |
| #include <linux/buffer_head.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/writeback.h> |
| #include <linux/swap.h> |
| #include <linux/delay.h> |
| #include <linux/bio.h> |
| #include <linux/gfs2_ondisk.h> |
| |
| #include "gfs2.h" |
| #include "incore.h" |
| #include "glock.h" |
| #include "glops.h" |
| #include "inode.h" |
| #include "log.h" |
| #include "lops.h" |
| #include "meta_io.h" |
| #include "rgrp.h" |
| #include "trans.h" |
| #include "util.h" |
| #include "trace_gfs2.h" |
| |
| static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| struct buffer_head *bh, *head; |
| int nr_underway = 0; |
| int write_flags = REQ_META | REQ_PRIO | wbc_to_write_flags(wbc); |
| |
| BUG_ON(!PageLocked(page)); |
| BUG_ON(!page_has_buffers(page)); |
| |
| head = page_buffers(page); |
| bh = head; |
| |
| do { |
| if (!buffer_mapped(bh)) |
| continue; |
| /* |
| * If it's a fully non-blocking write attempt and we cannot |
| * lock the buffer then redirty the page. Note that this can |
| * potentially cause a busy-wait loop from flusher thread and kswapd |
| * activity, but those code paths have their own higher-level |
| * throttling. |
| */ |
| if (wbc->sync_mode != WB_SYNC_NONE) { |
| lock_buffer(bh); |
| } else if (!trylock_buffer(bh)) { |
| redirty_page_for_writepage(wbc, page); |
| continue; |
| } |
| if (test_clear_buffer_dirty(bh)) { |
| mark_buffer_async_write(bh); |
| } else { |
| unlock_buffer(bh); |
| } |
| } while ((bh = bh->b_this_page) != head); |
| |
| /* |
| * The page and its buffers are protected by PageWriteback(), so we can |
| * drop the bh refcounts early. |
| */ |
| BUG_ON(PageWriteback(page)); |
| set_page_writeback(page); |
| |
| do { |
| struct buffer_head *next = bh->b_this_page; |
| if (buffer_async_write(bh)) { |
| submit_bh(REQ_OP_WRITE, write_flags, bh); |
| nr_underway++; |
| } |
| bh = next; |
| } while (bh != head); |
| unlock_page(page); |
| |
| if (nr_underway == 0) |
| end_page_writeback(page); |
| |
| return 0; |
| } |
| |
| const struct address_space_operations gfs2_meta_aops = { |
| .writepage = gfs2_aspace_writepage, |
| .releasepage = gfs2_releasepage, |
| }; |
| |
| const struct address_space_operations gfs2_rgrp_aops = { |
| .writepage = gfs2_aspace_writepage, |
| .releasepage = gfs2_releasepage, |
| }; |
| |
| /** |
| * gfs2_getbuf - Get a buffer with a given address space |
| * @gl: the glock |
| * @blkno: the block number (filesystem scope) |
| * @create: 1 if the buffer should be created |
| * |
| * Returns: the buffer |
| */ |
| |
| struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create) |
| { |
| struct address_space *mapping = gfs2_glock2aspace(gl); |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct page *page; |
| struct buffer_head *bh; |
| unsigned int shift; |
| unsigned long index; |
| unsigned int bufnum; |
| |
| if (mapping == NULL) |
| mapping = &sdp->sd_aspace; |
| |
| shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift; |
| index = blkno >> shift; /* convert block to page */ |
| bufnum = blkno - (index << shift); /* block buf index within page */ |
| |
| if (create) { |
| for (;;) { |
| page = grab_cache_page(mapping, index); |
| if (page) |
| break; |
| yield(); |
| } |
| } else { |
| page = find_get_page_flags(mapping, index, |
| FGP_LOCK|FGP_ACCESSED); |
| if (!page) |
| return NULL; |
| } |
| |
| if (!page_has_buffers(page)) |
| create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0); |
| |
| /* Locate header for our buffer within our page */ |
| for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page) |
| /* Do nothing */; |
| get_bh(bh); |
| |
| if (!buffer_mapped(bh)) |
| map_bh(bh, sdp->sd_vfs, blkno); |
| |
| unlock_page(page); |
| put_page(page); |
| |
| return bh; |
| } |
| |
| static void meta_prep_new(struct buffer_head *bh) |
| { |
| struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data; |
| |
| lock_buffer(bh); |
| clear_buffer_dirty(bh); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| mh->mh_magic = cpu_to_be32(GFS2_MAGIC); |
| } |
| |
| /** |
| * gfs2_meta_new - Get a block |
| * @gl: The glock associated with this block |
| * @blkno: The block number |
| * |
| * Returns: The buffer |
| */ |
| |
| struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno) |
| { |
| struct buffer_head *bh; |
| bh = gfs2_getbuf(gl, blkno, CREATE); |
| meta_prep_new(bh); |
| return bh; |
| } |
| |
| static void gfs2_meta_read_endio(struct bio *bio) |
| { |
| struct bio_vec *bvec; |
| struct bvec_iter_all iter_all; |
| |
| bio_for_each_segment_all(bvec, bio, iter_all) { |
| struct page *page = bvec->bv_page; |
| struct buffer_head *bh = page_buffers(page); |
| unsigned int len = bvec->bv_len; |
| |
| while (bh_offset(bh) < bvec->bv_offset) |
| bh = bh->b_this_page; |
| do { |
| struct buffer_head *next = bh->b_this_page; |
| len -= bh->b_size; |
| bh->b_end_io(bh, !bio->bi_status); |
| bh = next; |
| } while (bh && len); |
| } |
| bio_put(bio); |
| } |
| |
| /* |
| * Submit several consecutive buffer head I/O requests as a single bio I/O |
| * request. (See submit_bh_wbc.) |
| */ |
| static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[], |
| int num) |
| { |
| while (num > 0) { |
| struct buffer_head *bh = *bhs; |
| struct bio *bio; |
| |
| bio = bio_alloc(GFP_NOIO, num); |
| bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); |
| bio_set_dev(bio, bh->b_bdev); |
| while (num > 0) { |
| bh = *bhs; |
| if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) { |
| BUG_ON(bio->bi_iter.bi_size == 0); |
| break; |
| } |
| bhs++; |
| num--; |
| } |
| bio->bi_end_io = gfs2_meta_read_endio; |
| bio_set_op_attrs(bio, op, op_flags); |
| submit_bio(bio); |
| } |
| } |
| |
| /** |
| * gfs2_meta_read - Read a block from disk |
| * @gl: The glock covering the block |
| * @blkno: The block number |
| * @flags: flags |
| * @bhp: the place where the buffer is returned (NULL on failure) |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, |
| int rahead, struct buffer_head **bhp) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct buffer_head *bh, *bhs[2]; |
| int num = 0; |
| |
| if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { |
| *bhp = NULL; |
| return -EIO; |
| } |
| |
| *bhp = bh = gfs2_getbuf(gl, blkno, CREATE); |
| |
| lock_buffer(bh); |
| if (buffer_uptodate(bh)) { |
| unlock_buffer(bh); |
| flags &= ~DIO_WAIT; |
| } else { |
| bh->b_end_io = end_buffer_read_sync; |
| get_bh(bh); |
| bhs[num++] = bh; |
| } |
| |
| if (rahead) { |
| bh = gfs2_getbuf(gl, blkno + 1, CREATE); |
| |
| lock_buffer(bh); |
| if (buffer_uptodate(bh)) { |
| unlock_buffer(bh); |
| brelse(bh); |
| } else { |
| bh->b_end_io = end_buffer_read_sync; |
| bhs[num++] = bh; |
| } |
| } |
| |
| gfs2_submit_bhs(REQ_OP_READ, REQ_META | REQ_PRIO, bhs, num); |
| if (!(flags & DIO_WAIT)) |
| return 0; |
| |
| bh = *bhp; |
| wait_on_buffer(bh); |
| if (unlikely(!buffer_uptodate(bh))) { |
| struct gfs2_trans *tr = current->journal_info; |
| if (tr && test_bit(TR_TOUCHED, &tr->tr_flags)) |
| gfs2_io_error_bh_wd(sdp, bh); |
| brelse(bh); |
| *bhp = NULL; |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * gfs2_meta_wait - Reread a block from disk |
| * @sdp: the filesystem |
| * @bh: The block to wait for |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh) |
| { |
| if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
| return -EIO; |
| |
| wait_on_buffer(bh); |
| |
| if (!buffer_uptodate(bh)) { |
| struct gfs2_trans *tr = current->journal_info; |
| if (tr && test_bit(TR_TOUCHED, &tr->tr_flags)) |
| gfs2_io_error_bh_wd(sdp, bh); |
| return -EIO; |
| } |
| if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| void gfs2_remove_from_journal(struct buffer_head *bh, int meta) |
| { |
| struct address_space *mapping = bh->b_page->mapping; |
| struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); |
| struct gfs2_bufdata *bd = bh->b_private; |
| struct gfs2_trans *tr = current->journal_info; |
| int was_pinned = 0; |
| |
| if (test_clear_buffer_pinned(bh)) { |
| trace_gfs2_pin(bd, 0); |
| atomic_dec(&sdp->sd_log_pinned); |
| list_del_init(&bd->bd_list); |
| if (meta == REMOVE_META) |
| tr->tr_num_buf_rm++; |
| else |
| tr->tr_num_databuf_rm++; |
| set_bit(TR_TOUCHED, &tr->tr_flags); |
| was_pinned = 1; |
| brelse(bh); |
| } |
| if (bd) { |
| spin_lock(&sdp->sd_ail_lock); |
| if (bd->bd_tr) { |
| gfs2_trans_add_revoke(sdp, bd); |
| } else if (was_pinned) { |
| bh->b_private = NULL; |
| kmem_cache_free(gfs2_bufdata_cachep, bd); |
| } |
| spin_unlock(&sdp->sd_ail_lock); |
| } |
| clear_buffer_dirty(bh); |
| clear_buffer_uptodate(bh); |
| } |
| |
| /** |
| * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore |
| * @ip: the inode who owns the buffers |
| * @bstart: the first buffer in the run |
| * @blen: the number of buffers in the run |
| * |
| */ |
| |
| void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| struct buffer_head *bh; |
| |
| while (blen) { |
| bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE); |
| if (bh) { |
| lock_buffer(bh); |
| gfs2_log_lock(sdp); |
| gfs2_remove_from_journal(bh, REMOVE_META); |
| gfs2_log_unlock(sdp); |
| unlock_buffer(bh); |
| brelse(bh); |
| } |
| |
| bstart++; |
| blen--; |
| } |
| } |
| |
| /** |
| * gfs2_meta_indirect_buffer - Get a metadata buffer |
| * @ip: The GFS2 inode |
| * @height: The level of this buf in the metadata (indir addr) tree (if any) |
| * @num: The block number (device relative) of the buffer |
| * @bhp: the buffer is returned here |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num, |
| struct buffer_head **bhp) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| struct gfs2_glock *gl = ip->i_gl; |
| struct buffer_head *bh; |
| int ret = 0; |
| u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI; |
| int rahead = 0; |
| |
| if (num == ip->i_no_addr) |
| rahead = ip->i_rahead; |
| |
| ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh); |
| if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) { |
| brelse(bh); |
| ret = -EIO; |
| } else { |
| *bhp = bh; |
| } |
| return ret; |
| } |
| |
| /** |
| * gfs2_meta_ra - start readahead on an extent of a file |
| * @gl: the glock the blocks belong to |
| * @dblock: the starting disk block |
| * @extlen: the number of blocks in the extent |
| * |
| * returns: the first buffer in the extent |
| */ |
| |
| struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct buffer_head *first_bh, *bh; |
| u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >> |
| sdp->sd_sb.sb_bsize_shift; |
| |
| BUG_ON(!extlen); |
| |
| if (max_ra < 1) |
| max_ra = 1; |
| if (extlen > max_ra) |
| extlen = max_ra; |
| |
| first_bh = gfs2_getbuf(gl, dblock, CREATE); |
| |
| if (buffer_uptodate(first_bh)) |
| goto out; |
| if (!buffer_locked(first_bh)) |
| ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &first_bh); |
| |
| dblock++; |
| extlen--; |
| |
| while (extlen) { |
| bh = gfs2_getbuf(gl, dblock, CREATE); |
| |
| if (!buffer_uptodate(bh) && !buffer_locked(bh)) |
| ll_rw_block(REQ_OP_READ, |
| REQ_RAHEAD | REQ_META | REQ_PRIO, |
| 1, &bh); |
| brelse(bh); |
| dblock++; |
| extlen--; |
| if (!buffer_locked(first_bh) && buffer_uptodate(first_bh)) |
| goto out; |
| } |
| |
| wait_on_buffer(first_bh); |
| out: |
| return first_bh; |
| } |
| |