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- /*
- * 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_op = REQ_META | REQ_PRIO |
- (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
- 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(write_op, 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_CACHE_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);
- page_cache_release(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;
- }
- /**
- * 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,
- struct buffer_head **bhp)
- {
- struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct buffer_head *bh;
- 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);
- return 0;
- }
- bh->b_end_io = end_buffer_read_sync;
- get_bh(bh);
- submit_bh(READ_SYNC | REQ_META | REQ_PRIO, bh);
- if (!(flags & DIO_WAIT))
- return 0;
- wait_on_buffer(bh);
- if (unlikely(!buffer_uptodate(bh))) {
- struct gfs2_trans *tr = current->journal_info;
- if (tr && tr->tr_touched)
- gfs2_io_error_bh(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 && tr->tr_touched)
- gfs2_io_error_bh(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, struct gfs2_trans *tr, int meta)
- {
- struct address_space *mapping = bh->b_page->mapping;
- struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
- struct gfs2_bufdata *bd = bh->b_private;
- 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)
- tr->tr_num_buf_rm++;
- else
- tr->tr_num_databuf_rm++;
- tr->tr_touched = 1;
- 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, current->journal_info, 1);
- 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;
- ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
- if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
- brelse(bh);
- ret = -EIO;
- }
- *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(READ_SYNC | REQ_META, 1, &first_bh);
- dblock++;
- extlen--;
- while (extlen) {
- bh = gfs2_getbuf(gl, dblock, CREATE);
- if (!buffer_uptodate(bh) && !buffer_locked(bh))
- ll_rw_block(READA | REQ_META, 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;
- }
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