/* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright (C) 2004-2006 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 <linux/lm_interface.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 "ops_address.h" static int aspace_get_block(struct inode *inode, sector_t lblock, struct buffer_head *bh_result, int create) { gfs2_assert_warn(inode->i_sb->s_fs_info, 0); return -EOPNOTSUPP; } static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, aspace_get_block, wbc); } static const struct address_space_operations aspace_aops = { .writepage = gfs2_aspace_writepage, .releasepage = gfs2_releasepage, }; /** * gfs2_aspace_get - Create and initialize a struct inode structure * @sdp: the filesystem the aspace is in * * Right now a struct inode is just a struct inode. Maybe Linux * will supply a more lightweight address space construct (that works) * in the future. * * Make sure pages/buffers in this aspace aren't in high memory. * * Returns: the aspace */ struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp) { struct inode *aspace; aspace = new_inode(sdp->sd_vfs); if (aspace) { mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS); aspace->i_mapping->a_ops = &aspace_aops; aspace->i_size = ~0ULL; aspace->i_private = NULL; insert_inode_hash(aspace); } return aspace; } void gfs2_aspace_put(struct inode *aspace) { remove_inode_hash(aspace); iput(aspace); } /** * gfs2_meta_inval - Invalidate all buffers associated with a glock * @gl: the glock * */ void gfs2_meta_inval(struct gfs2_glock *gl) { struct gfs2_sbd *sdp = gl->gl_sbd; struct inode *aspace = gl->gl_aspace; struct address_space *mapping = gl->gl_aspace->i_mapping; gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count)); atomic_inc(&aspace->i_writecount); truncate_inode_pages(mapping, 0); atomic_dec(&aspace->i_writecount); gfs2_assert_withdraw(sdp, !mapping->nrpages); } /** * gfs2_meta_sync - Sync all buffers associated with a glock * @gl: The glock * */ void gfs2_meta_sync(struct gfs2_glock *gl) { struct address_space *mapping = gl->gl_aspace->i_mapping; int error; filemap_fdatawrite(mapping); error = filemap_fdatawait(mapping); if (error) gfs2_io_error(gl->gl_sbd); } /** * 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 */ static struct buffer_head *getbuf(struct gfs2_glock *gl, u64 blkno, int create) { struct address_space *mapping = gl->gl_aspace->i_mapping; struct gfs2_sbd *sdp = gl->gl_sbd; struct page *page; struct buffer_head *bh; unsigned int shift; unsigned long index; unsigned int bufnum; 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_lock_page(mapping, index); 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); mark_page_accessed(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 = 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) { *bhp = getbuf(gl, blkno, CREATE); if (!buffer_uptodate(*bhp)) ll_rw_block(READ_META, 1, bhp); if (flags & DIO_WAIT) { int error = gfs2_meta_wait(gl->gl_sbd, *bhp); if (error) { brelse(*bhp); return error; } } 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; } /** * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer * @gl: the glock the buffer belongs to * @bh: The buffer to be attached to * @meta: Flag to indicate whether its metadata or not */ void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh, int meta) { struct gfs2_bufdata *bd; if (meta) lock_page(bh->b_page); if (bh->b_private) { if (meta) unlock_page(bh->b_page); return; } bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL), memset(bd, 0, sizeof(struct gfs2_bufdata)); bd->bd_bh = bh; bd->bd_gl = gl; INIT_LIST_HEAD(&bd->bd_list_tr); if (meta) lops_init_le(&bd->bd_le, &gfs2_buf_lops); else lops_init_le(&bd->bd_le, &gfs2_databuf_lops); bh->b_private = bd; if (meta) unlock_page(bh->b_page); } /** * gfs2_pin - Pin a buffer in memory * @sdp: the filesystem the buffer belongs to * @bh: The buffer to be pinned * */ void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh) { struct gfs2_bufdata *bd = bh->b_private; gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)); if (test_set_buffer_pinned(bh)) gfs2_assert_withdraw(sdp, 0); wait_on_buffer(bh); /* If this buffer is in the AIL and it has already been written to in-place disk block, remove it from the AIL. */ gfs2_log_lock(sdp); if (bd->bd_ail && !buffer_in_io(bh)) list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list); gfs2_log_unlock(sdp); clear_buffer_dirty(bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) gfs2_io_error_bh(sdp, bh); get_bh(bh); } /** * gfs2_unpin - Unpin a buffer * @sdp: the filesystem the buffer belongs to * @bh: The buffer to unpin * @ai: * */ void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh, struct gfs2_ail *ai) { struct gfs2_bufdata *bd = bh->b_private; gfs2_assert_withdraw(sdp, buffer_uptodate(bh)); if (!buffer_pinned(bh)) gfs2_assert_withdraw(sdp, 0); mark_buffer_dirty(bh); clear_buffer_pinned(bh); gfs2_log_lock(sdp); if (bd->bd_ail) { list_del(&bd->bd_ail_st_list); brelse(bh); } else { struct gfs2_glock *gl = bd->bd_gl; list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list); atomic_inc(&gl->gl_ail_count); } bd->bd_ail = ai; list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list); gfs2_log_unlock(sdp); } /** * 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 = getbuf(ip->i_gl, bstart, NO_CREATE); if (bh) { struct gfs2_bufdata *bd = bh->b_private; if (test_clear_buffer_pinned(bh)) { struct gfs2_trans *tr = current->journal_info; gfs2_log_lock(sdp); list_del_init(&bd->bd_le.le_list); gfs2_assert_warn(sdp, sdp->sd_log_num_buf); sdp->sd_log_num_buf--; gfs2_log_unlock(sdp); tr->tr_num_buf_rm++; brelse(bh); } if (bd) { gfs2_log_lock(sdp); if (bd->bd_ail) { u64 blkno = bh->b_blocknr; bd->bd_ail = NULL; list_del(&bd->bd_ail_st_list); list_del(&bd->bd_ail_gl_list); atomic_dec(&bd->bd_gl->gl_ail_count); brelse(bh); gfs2_log_unlock(sdp); gfs2_trans_add_revoke(sdp, blkno); } else gfs2_log_unlock(sdp); } lock_buffer(bh); clear_buffer_dirty(bh); clear_buffer_uptodate(bh); unlock_buffer(bh); brelse(bh); } bstart++; blen--; } } /** * gfs2_meta_cache_flush - get rid of any references on buffers for this inode * @ip: The GFS2 inode * * This releases buffers that are in the most-recently-used array of * blocks used for indirect block addressing for this inode. */ void gfs2_meta_cache_flush(struct gfs2_inode *ip) { struct buffer_head **bh_slot; unsigned int x; spin_lock(&ip->i_spin); for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) { bh_slot = &ip->i_cache[x]; if (!*bh_slot) break; brelse(*bh_slot); *bh_slot = NULL; } spin_unlock(&ip->i_spin); } /** * 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 * @new: Non-zero if we may create a new buffer * @bhp: the buffer is returned here * * Try to use the gfs2_inode's MRU metadata tree cache. * * Returns: errno */ int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num, int new, struct buffer_head **bhp) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_glock *gl = ip->i_gl; struct buffer_head *bh = NULL, **bh_slot = ip->i_cache + height; int in_cache = 0; BUG_ON(!gl); BUG_ON(!sdp); spin_lock(&ip->i_spin); if (*bh_slot && (*bh_slot)->b_blocknr == num) { bh = *bh_slot; get_bh(bh); in_cache = 1; } spin_unlock(&ip->i_spin); if (!bh) bh = getbuf(gl, num, CREATE); if (!bh) return -ENOBUFS; if (new) { if (gfs2_assert_warn(sdp, height)) goto err; meta_prep_new(bh); gfs2_trans_add_bh(ip->i_gl, bh, 1); gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN); gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header)); } else { u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI; if (!buffer_uptodate(bh)) { ll_rw_block(READ_META, 1, &bh); if (gfs2_meta_wait(sdp, bh)) goto err; } if (gfs2_metatype_check(sdp, bh, mtype)) goto err; } if (!in_cache) { spin_lock(&ip->i_spin); if (*bh_slot) brelse(*bh_slot); *bh_slot = bh; get_bh(bh); spin_unlock(&ip->i_spin); } *bhp = bh; return 0; err: brelse(bh); return -EIO; } /** * 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_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 = getbuf(gl, dblock, CREATE); if (buffer_uptodate(first_bh)) goto out; if (!buffer_locked(first_bh)) ll_rw_block(READ_META, 1, &first_bh); dblock++; extlen--; while (extlen) { bh = getbuf(gl, dblock, CREATE); if (!buffer_uptodate(bh) && !buffer_locked(bh)) ll_rw_block(READA, 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; }