diff options
Diffstat (limited to 'fs/gfs2/ops_address.c')
| -rw-r--r-- | fs/gfs2/ops_address.c | 790 |
1 files changed, 790 insertions, 0 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c new file mode 100644 index 0000000000000..4fb743f4e4a42 --- /dev/null +++ b/fs/gfs2/ops_address.c @@ -0,0 +1,790 @@ +/* + * 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/pagemap.h> +#include <linux/pagevec.h> +#include <linux/mpage.h> +#include <linux/fs.h> +#include <linux/gfs2_ondisk.h> +#include <linux/lm_interface.h> + +#include "gfs2.h" +#include "incore.h" +#include "bmap.h" +#include "glock.h" +#include "inode.h" +#include "log.h" +#include "meta_io.h" +#include "ops_address.h" +#include "quota.h" +#include "trans.h" +#include "rgrp.h" +#include "ops_file.h" +#include "util.h" +#include "glops.h" + + +static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, + unsigned int from, unsigned int to) +{ + struct buffer_head *head = page_buffers(page); + unsigned int bsize = head->b_size; + struct buffer_head *bh; + unsigned int start, end; + + for (bh = head, start = 0; bh != head || !start; + bh = bh->b_this_page, start = end) { + end = start + bsize; + if (end <= from || start >= to) + continue; + gfs2_trans_add_bh(ip->i_gl, bh, 0); + } +} + +/** + * gfs2_get_block - Fills in a buffer head with details about a block + * @inode: The inode + * @lblock: The block number to look up + * @bh_result: The buffer head to return the result in + * @create: Non-zero if we may add block to the file + * + * Returns: errno + */ + +int gfs2_get_block(struct inode *inode, sector_t lblock, + struct buffer_head *bh_result, int create) +{ + return gfs2_block_map(inode, lblock, create, bh_result, 32); +} + +/** + * gfs2_get_block_noalloc - Fills in a buffer head with details about a block + * @inode: The inode + * @lblock: The block number to look up + * @bh_result: The buffer head to return the result in + * @create: Non-zero if we may add block to the file + * + * Returns: errno + */ + +static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock, + struct buffer_head *bh_result, int create) +{ + int error; + + error = gfs2_block_map(inode, lblock, 0, bh_result, 1); + if (error) + return error; + if (bh_result->b_blocknr == 0) + return -EIO; + return 0; +} + +static int gfs2_get_block_direct(struct inode *inode, sector_t lblock, + struct buffer_head *bh_result, int create) +{ + return gfs2_block_map(inode, lblock, 0, bh_result, 32); +} + +/** + * gfs2_writepage - Write complete page + * @page: Page to write + * + * Returns: errno + * + * Some of this is copied from block_write_full_page() although we still + * call it to do most of the work. + */ + +static int gfs2_writepage(struct page *page, struct writeback_control *wbc) +{ + struct inode *inode = page->mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + loff_t i_size = i_size_read(inode); + pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; + unsigned offset; + int error; + int done_trans = 0; + + if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) { + unlock_page(page); + return -EIO; + } + if (current->journal_info) + goto out_ignore; + + /* Is the page fully outside i_size? (truncate in progress) */ + offset = i_size & (PAGE_CACHE_SIZE-1); + if (page->index > end_index || (page->index == end_index && !offset)) { + page->mapping->a_ops->invalidatepage(page, 0); + unlock_page(page); + return 0; /* don't care */ + } + + if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) { + error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); + if (error) + goto out_ignore; + if (!page_has_buffers(page)) { + create_empty_buffers(page, inode->i_sb->s_blocksize, + (1 << BH_Dirty)|(1 << BH_Uptodate)); + } + gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); + done_trans = 1; + } + error = block_write_full_page(page, gfs2_get_block_noalloc, wbc); + if (done_trans) + gfs2_trans_end(sdp); + gfs2_meta_cache_flush(ip); + return error; + +out_ignore: + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return 0; +} + +static int zero_readpage(struct page *page) +{ + void *kaddr; + + kaddr = kmap_atomic(page, KM_USER0); + memset(kaddr, 0, PAGE_CACHE_SIZE); + kunmap_atomic(page, KM_USER0); + + SetPageUptodate(page); + + return 0; +} + +/** + * stuffed_readpage - Fill in a Linux page with stuffed file data + * @ip: the inode + * @page: the page + * + * Returns: errno + */ + +static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) +{ + struct buffer_head *dibh; + void *kaddr; + int error; + + /* Only the first page of a stuffed file might contain data */ + if (unlikely(page->index)) + return zero_readpage(page); + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + return error; + + kaddr = kmap_atomic(page, KM_USER0); + memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), + ip->i_di.di_size); + memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size); + kunmap_atomic(page, KM_USER0); + + brelse(dibh); + + SetPageUptodate(page); + + return 0; +} + + +/** + * gfs2_readpage - readpage with locking + * @file: The file to read a page for. N.B. This may be NULL if we are + * reading an internal file. + * @page: The page to read + * + * Returns: errno + */ + +static int gfs2_readpage(struct file *file, struct page *page) +{ + struct gfs2_inode *ip = GFS2_I(page->mapping->host); + struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); + struct gfs2_file *gf = NULL; + struct gfs2_holder gh; + int error; + int do_unlock = 0; + + if (likely(file != &gfs2_internal_file_sentinel)) { + if (file) { + gf = file->private_data; + if (test_bit(GFF_EXLOCK, &gf->f_flags)) + /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */ + goto skip_lock; + } + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh); + do_unlock = 1; + error = gfs2_glock_nq_m_atime(1, &gh); + if (unlikely(error)) + goto out_unlock; + } + +skip_lock: + if (gfs2_is_stuffed(ip)) { + error = stuffed_readpage(ip, page); + unlock_page(page); + } else + error = mpage_readpage(page, gfs2_get_block); + + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) + error = -EIO; + + if (do_unlock) { + gfs2_glock_dq_m(1, &gh); + gfs2_holder_uninit(&gh); + } +out: + return error; +out_unlock: + unlock_page(page); + if (do_unlock) + gfs2_holder_uninit(&gh); + goto out; +} + +/** + * gfs2_readpages - Read a bunch of pages at once + * + * Some notes: + * 1. This is only for readahead, so we can simply ignore any things + * which are slightly inconvenient (such as locking conflicts between + * the page lock and the glock) and return having done no I/O. Its + * obviously not something we'd want to do on too regular a basis. + * Any I/O we ignore at this time will be done via readpage later. + * 2. We have to handle stuffed files here too. + * 3. mpage_readpages() does most of the heavy lifting in the common case. + * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places. + * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as + * well as read-ahead. + */ +static int gfs2_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + struct inode *inode = mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_holder gh; + unsigned page_idx; + int ret; + int do_unlock = 0; + + if (likely(file != &gfs2_internal_file_sentinel)) { + if (file) { + struct gfs2_file *gf = file->private_data; + if (test_bit(GFF_EXLOCK, &gf->f_flags)) + goto skip_lock; + } + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, + LM_FLAG_TRY_1CB|GL_ATIME|GL_AOP, &gh); + do_unlock = 1; + ret = gfs2_glock_nq_m_atime(1, &gh); + if (ret == GLR_TRYFAILED) + goto out_noerror; + if (unlikely(ret)) + goto out_unlock; + } +skip_lock: + if (gfs2_is_stuffed(ip)) { + struct pagevec lru_pvec; + pagevec_init(&lru_pvec, 0); + for (page_idx = 0; page_idx < nr_pages; page_idx++) { + struct page *page = list_entry(pages->prev, struct page, lru); + prefetchw(&page->flags); + list_del(&page->lru); + if (!add_to_page_cache(page, mapping, + page->index, GFP_KERNEL)) { + ret = stuffed_readpage(ip, page); + unlock_page(page); + if (!pagevec_add(&lru_pvec, page)) + __pagevec_lru_add(&lru_pvec); + } else { + page_cache_release(page); + } + } + pagevec_lru_add(&lru_pvec); + ret = 0; + } else { + /* What we really want to do .... */ + ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block); + } + + if (do_unlock) { + gfs2_glock_dq_m(1, &gh); + gfs2_holder_uninit(&gh); + } +out: + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) + ret = -EIO; + return ret; +out_noerror: + ret = 0; +out_unlock: + /* unlock all pages, we can't do any I/O right now */ + for (page_idx = 0; page_idx < nr_pages; page_idx++) { + struct page *page = list_entry(pages->prev, struct page, lru); + list_del(&page->lru); + unlock_page(page); + page_cache_release(page); + } + if (do_unlock) + gfs2_holder_uninit(&gh); + goto out; +} + +/** + * gfs2_prepare_write - Prepare to write a page to a file + * @file: The file to write to + * @page: The page which is to be prepared for writing + * @from: From (byte range within page) + * @to: To (byte range within page) + * + * Returns: errno + */ + +static int gfs2_prepare_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + struct gfs2_inode *ip = GFS2_I(page->mapping->host); + struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); + unsigned int data_blocks, ind_blocks, rblocks; + int alloc_required; + int error = 0; + loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from; + loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; + struct gfs2_alloc *al; + + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh); + error = gfs2_glock_nq_m_atime(1, &ip->i_gh); + if (error) + goto out_uninit; + + gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks); + + error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required); + if (error) + goto out_unlock; + + + if (alloc_required) { + al = gfs2_alloc_get(ip); + + error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); + if (error) + goto out_alloc_put; + + error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid); + if (error) + goto out_qunlock; + + al->al_requested = data_blocks + ind_blocks; + error = gfs2_inplace_reserve(ip); + if (error) + goto out_qunlock; + } + + rblocks = RES_DINODE + ind_blocks; + if (gfs2_is_jdata(ip)) + rblocks += data_blocks ? data_blocks : 1; + if (ind_blocks || data_blocks) + rblocks += RES_STATFS + RES_QUOTA; + + error = gfs2_trans_begin(sdp, rblocks, 0); + if (error) + goto out; + + if (gfs2_is_stuffed(ip)) { + if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { + error = gfs2_unstuff_dinode(ip, page); + if (error == 0) + goto prepare_write; + } else if (!PageUptodate(page)) + error = stuffed_readpage(ip, page); + goto out; + } + +prepare_write: + error = block_prepare_write(page, from, to, gfs2_get_block); + +out: + if (error) { + gfs2_trans_end(sdp); + if (alloc_required) { + gfs2_inplace_release(ip); +out_qunlock: + gfs2_quota_unlock(ip); +out_alloc_put: + gfs2_alloc_put(ip); + } +out_unlock: + gfs2_glock_dq_m(1, &ip->i_gh); +out_uninit: + gfs2_holder_uninit(&ip->i_gh); + } + + return error; +} + +/** + * gfs2_commit_write - Commit write to a file + * @file: The file to write to + * @page: The page containing the data + * @from: From (byte range within page) + * @to: To (byte range within page) + * + * Returns: errno + */ + +static int gfs2_commit_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + struct inode *inode = page->mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + int error = -EOPNOTSUPP; + struct buffer_head *dibh; + struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_dinode *di; + + if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) + goto fail_nounlock; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto fail_endtrans; + + gfs2_trans_add_bh(ip->i_gl, dibh, 1); + di = (struct gfs2_dinode *)dibh->b_data; + + if (gfs2_is_stuffed(ip)) { + u64 file_size; + void *kaddr; + + file_size = ((u64)page->index << PAGE_CACHE_SHIFT) + to; + + kaddr = kmap_atomic(page, KM_USER0); + memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from, + kaddr + from, to - from); + kunmap_atomic(page, KM_USER0); + + SetPageUptodate(page); + + if (inode->i_size < file_size) + i_size_write(inode, file_size); + } else { + if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || + gfs2_is_jdata(ip)) + gfs2_page_add_databufs(ip, page, from, to); + error = generic_commit_write(file, page, from, to); + if (error) + goto fail; + } + + if (ip->i_di.di_size < inode->i_size) { + ip->i_di.di_size = inode->i_size; + di->di_size = cpu_to_be64(inode->i_size); + } + + di->di_mode = cpu_to_be32(inode->i_mode); + di->di_atime = cpu_to_be64(inode->i_atime.tv_sec); + di->di_mtime = cpu_to_be64(inode->i_mtime.tv_sec); + di->di_ctime = cpu_to_be64(inode->i_ctime.tv_sec); + + brelse(dibh); + gfs2_trans_end(sdp); + if (al->al_requested) { + gfs2_inplace_release(ip); + gfs2_quota_unlock(ip); + gfs2_alloc_put(ip); + } + gfs2_glock_dq_m(1, &ip->i_gh); + gfs2_holder_uninit(&ip->i_gh); + return 0; + +fail: + brelse(dibh); +fail_endtrans: + gfs2_trans_end(sdp); + if (al->al_requested) { + gfs2_inplace_release(ip); + gfs2_quota_unlock(ip); + gfs2_alloc_put(ip); + } + gfs2_glock_dq_m(1, &ip->i_gh); + gfs2_holder_uninit(&ip->i_gh); +fail_nounlock: + ClearPageUptodate(page); + return error; +} + +/** + * gfs2_bmap - Block map function + * @mapping: Address space info + * @lblock: The block to map + * + * Returns: The disk address for the block or 0 on hole or error + */ + +static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) +{ + struct gfs2_inode *ip = GFS2_I(mapping->host); + struct gfs2_holder i_gh; + sector_t dblock = 0; + int error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); + if (error) + return 0; + + if (!gfs2_is_stuffed(ip)) + dblock = generic_block_bmap(mapping, lblock, gfs2_get_block); + + gfs2_glock_dq_uninit(&i_gh); + + return dblock; +} + +static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh) +{ + struct gfs2_bufdata *bd; + + gfs2_log_lock(sdp); + bd = bh->b_private; + if (bd) { + bd->bd_bh = NULL; + bh->b_private = NULL; + } + gfs2_log_unlock(sdp); + + lock_buffer(bh); + clear_buffer_dirty(bh); + bh->b_bdev = NULL; + clear_buffer_mapped(bh); + clear_buffer_req(bh); + clear_buffer_new(bh); + clear_buffer_delay(bh); + unlock_buffer(bh); +} + +static void gfs2_invalidatepage(struct page *page, unsigned long offset) +{ + struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); + struct buffer_head *head, *bh, *next; + unsigned int curr_off = 0; + + BUG_ON(!PageLocked(page)); + if (!page_has_buffers(page)) + return; + + bh = head = page_buffers(page); + do { + unsigned int next_off = curr_off + bh->b_size; + next = bh->b_this_page; + + if (offset <= curr_off) + discard_buffer(sdp, bh); + + curr_off = next_off; + bh = next; + } while (bh != head); + + if (!offset) + try_to_release_page(page, 0); + + return; +} + +static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, + const struct iovec *iov, loff_t offset, + unsigned long nr_segs) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + int rv; + + if (rw == READ) + mutex_lock(&inode->i_mutex); + /* + * Shared lock, even if its a write, since we do no allocation + * on this path. All we need change is atime. + */ + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh); + rv = gfs2_glock_nq_m_atime(1, &gh); + if (rv) + goto out; + + if (offset > i_size_read(inode)) + goto out; + + /* + * Should we return an error here? I can't see that O_DIRECT for + * a journaled file makes any sense. For now we'll silently fall + * back to buffered I/O, likewise we do the same for stuffed + * files since they are (a) small and (b) unaligned. + */ + if (gfs2_is_jdata(ip)) + goto out; + + if (gfs2_is_stuffed(ip)) + goto out; + + rv = blockdev_direct_IO_own_locking(rw, iocb, inode, + inode->i_sb->s_bdev, + iov, offset, nr_segs, + gfs2_get_block_direct, NULL); +out: + gfs2_glock_dq_m(1, &gh); + gfs2_holder_uninit(&gh); + if (rw == READ) + mutex_unlock(&inode->i_mutex); + + return rv; +} + +/** + * stuck_releasepage - We're stuck in gfs2_releasepage(). Print stuff out. + * @bh: the buffer we're stuck on + * + */ + +static void stuck_releasepage(struct buffer_head *bh) +{ + struct inode *inode = bh->b_page->mapping->host; + struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; + struct gfs2_bufdata *bd = bh->b_private; + struct gfs2_glock *gl; +static unsigned limit = 0; + + if (limit > 3) + return; + limit++; + + fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode); + fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n", + (unsigned long long)bh->b_blocknr, atomic_read(&bh->b_count)); + fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh)); + fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL"); + + if (!bd) + return; + + gl = bd->bd_gl; + + fs_warn(sdp, "gl = (%u, %llu)\n", + gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number); + + fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n", + (list_empty(&bd->bd_list_tr)) ? "no" : "yes", + (list_empty(&bd->bd_le.le_list)) ? "no" : "yes"); + + if (gl->gl_ops == &gfs2_inode_glops) { + struct gfs2_inode *ip = gl->gl_object; + unsigned int x; + + if (!ip) + return; + + fs_warn(sdp, "ip = %llu %llu\n", + (unsigned long long)ip->i_num.no_formal_ino, + (unsigned long long)ip->i_num.no_addr); + + for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) + fs_warn(sdp, "ip->i_cache[%u] = %s\n", + x, (ip->i_cache[x]) ? "!NULL" : "NULL"); + } +} + +/** + * gfs2_releasepage - free the metadata associated with a page + * @page: the page that's being released + * @gfp_mask: passed from Linux VFS, ignored by us + * + * Call try_to_free_buffers() if the buffers in this page can be + * released. + * + * Returns: 0 + */ + +int gfs2_releasepage(struct page *page, gfp_t gfp_mask) +{ + struct inode *aspace = page->mapping->host; + struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info; + struct buffer_head *bh, *head; + struct gfs2_bufdata *bd; + unsigned long t = jiffies + gfs2_tune_get(sdp, gt_stall_secs) * HZ; + + if (!page_has_buffers(page)) + goto out; + + head = bh = page_buffers(page); + do { + while (atomic_read(&bh->b_count)) { + if (!atomic_read(&aspace->i_writecount)) + return 0; + + if (time_after_eq(jiffies, t)) { + stuck_releasepage(bh); + /* should we withdraw here? */ + return 0; + } + + yield(); + } + + gfs2_assert_warn(sdp, !buffer_pinned(bh)); + gfs2_assert_warn(sdp, !buffer_dirty(bh)); + + gfs2_log_lock(sdp); + bd = bh->b_private; + if (bd) { + gfs2_assert_warn(sdp, bd->bd_bh == bh); + gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr)); + gfs2_assert_warn(sdp, !bd->bd_ail); + bd->bd_bh = NULL; + if (!list_empty(&bd->bd_le.le_list)) + bd = NULL; + bh->b_private = NULL; + } + gfs2_log_unlock(sdp); + if (bd) + kmem_cache_free(gfs2_bufdata_cachep, bd); + + bh = bh->b_this_page; + } while (bh != head); + +out: + return try_to_free_buffers(page); +} + +const struct address_space_operations gfs2_file_aops = { + .writepage = gfs2_writepage, + .readpage = gfs2_readpage, + .readpages = gfs2_readpages, + .sync_page = block_sync_page, + .prepare_write = gfs2_prepare_write, + .commit_write = gfs2_commit_write, + .bmap = gfs2_bmap, + .invalidatepage = gfs2_invalidatepage, + .releasepage = gfs2_releasepage, + .direct_IO = gfs2_direct_IO, +}; + |