static int jread(struct buffer_head **bhp, journal_t *journal, unsigned int offset) { int err; unsigned long long blocknr; struct buffer_head *bh; *bhp = NULL; if (offset >= journal->j_maxlen) { printk(KERN_ERR "JBD: corrupted journal superblock\n"); return -EIO; } err = jbd2_journal_bmap(journal, offset, &blocknr); if (err) { printk (KERN_ERR "JBD: bad block at offset %u\n", offset); return err; } bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); if (!bh) return -ENOMEM; if(buffer_uptodate(bh)){ if (!trylock_buffer(bh)){ lock_buffer(bh); printk("debug:concurrent exist \n"); } unlock_buffer(bh); } if (!buffer_uptodate(bh)) { /* If this is a brand new buffer, start readahead. Otherwise, we assume we are already reading it. */ if (!buffer_req(bh)) do_readahead(journal, offset); wait_on_buffer(bh); } if (!buffer_uptodate(bh)) { printk (KERN_ERR "JBD: Failed to read block at offset %u\n", offset); brelse(bh); return -EIO; } *bhp = bh; return 0; }
static int jread(struct buffer_head **bhp, journal_t *journal, unsigned int offset) { unsigned int blocknr; struct buffer_head *bh; *bhp = NULL; J_ASSERT (offset < journal->j_maxlen); blocknr = offset; if (journal->j_inode) blocknr = bmap(journal->j_inode, offset); if (!blocknr) { printk (KERN_ERR "JFS: bad block at offset %u\n", offset); return -EIO; } bh = getblk(journal->j_dev, blocknr, journal->j_blocksize); if (!bh) return -ENOMEM; if (!buffer_uptodate(bh)) { /* If this is a brand new buffer, start readahead. Otherwise, we assume we are already reading it. */ if (!buffer_req(bh)) do_readahead(journal, offset); wait_on_buffer(bh); } if (!buffer_uptodate(bh)) { printk (KERN_ERR "JFS: Failed to read block at offset %u\n", offset); brelse(bh); return -EIO; } *bhp = bh; return 0; }
static int jread(struct buffer_head **bhp, journal_t *journal, unsigned int offset) { int err; unsigned long long blocknr; struct buffer_head *bh; *bhp = NULL; if (offset >= journal->j_maxlen) { printk(KERN_ERR "JBD2: corrupted journal superblock\n"); return -EIO; } err = jbd2_journal_bmap(journal, offset, &blocknr); if (err) { printk(KERN_ERR "JBD2: bad block at offset %u\n", offset); return err; } bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); if (!bh) return -ENOMEM; if (!buffer_uptodate(bh)) { if (!buffer_req(bh)) do_readahead(journal, offset); wait_on_buffer(bh); } if (!buffer_uptodate(bh)) { printk(KERN_ERR "JBD2: Failed to read block at offset %u\n", offset); brelse(bh); return -EIO; } *bhp = bh; return 0; }