/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * dir.c * * Creates, reads, walks and deletes directory-nodes * * Copyright (C) 2002, 2004 Oracle. All rights reserved. * * Portions of this code from linux/fs/ext3/dir.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/dir.c * * Copyright (C) 1991, 1992 Linux Torvalds * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/fs.h> #include <linux/types.h> #include <linux/slab.h> #include <linux/highmem.h> #define MLOG_MASK_PREFIX ML_NAMEI #include <cluster/masklog.h> #include "ocfs2.h" #include "alloc.h" #include "dir.h" #include "dlmglue.h" #include "extent_map.h" #include "file.h" #include "inode.h" #include "journal.h" #include "namei.h" #include "suballoc.h" #include "uptodate.h" #include "buffer_head_io.h" static unsigned char ocfs2_filetype_table[] = { DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK }; static int ocfs2_extend_dir(struct ocfs2_super *osb, struct inode *dir, struct buffer_head *parent_fe_bh, struct buffer_head **new_de_bh); /* * ocfs2_readdir() * */ int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir) { int error = 0; unsigned long offset, blk, last_ra_blk = 0; int i, stored; struct buffer_head * bh, * tmp; struct ocfs2_dir_entry * de; int err; struct inode *inode = filp->f_dentry->d_inode; struct super_block * sb = inode->i_sb; unsigned int ra_sectors = 16; mlog_entry("dirino=%llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); stored = 0; bh = NULL; error = ocfs2_meta_lock(inode, NULL, NULL, 0); if (error < 0) { if (error != -ENOENT) mlog_errno(error); /* we haven't got any yet, so propagate the error. */ stored = error; goto bail_nolock; } offset = filp->f_pos & (sb->s_blocksize - 1); while (!error && !stored && filp->f_pos < i_size_read(inode)) { blk = (filp->f_pos) >> sb->s_blocksize_bits; bh = ocfs2_bread(inode, blk, &err, 0); if (!bh) { mlog(ML_ERROR, "directory #%llu contains a hole at offset %lld\n", (unsigned long long)OCFS2_I(inode)->ip_blkno, filp->f_pos); filp->f_pos += sb->s_blocksize - offset; continue; } /* The idea here is to begin with 8k read-ahead and to stay * 4k ahead of our current position. * * TODO: Use the pagecache for this. We just need to * make sure it's cluster-safe... */ if (!last_ra_blk || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) { for (i = ra_sectors >> (sb->s_blocksize_bits - 9); i > 0; i--) { tmp = ocfs2_bread(inode, ++blk, &err, 1); if (tmp) brelse(tmp); } last_ra_blk = blk; ra_sectors = 8; } revalidate: /* If the dir block has changed since the last call to * readdir(2), then we might be pointing to an invalid * dirent right now. Scan from the start of the block * to make sure. */ if (filp->f_version != inode->i_version) { for (i = 0; i < sb->s_blocksize && i < offset; ) { de = (struct ocfs2_dir_entry *) (bh->b_data + i); /* It's too expensive to do a full * dirent test each time round this * loop, but we do have to test at * least that it is non-zero. A * failure will be detected in the * dirent test below. */ if (le16_to_cpu(de->rec_len) < OCFS2_DIR_REC_LEN(1)) break; i += le16_to_cpu(de->rec_len); } offset = i; filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) | offset; filp->f_version = inode->i_version; } while (!error && filp->f_pos < i_size_read(inode) && offset < sb->s_blocksize) { de = (struct ocfs2_dir_entry *) (bh->b_data + offset); if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { /* On error, skip the f_pos to the next block. */ filp->f_pos = (filp->f_pos | (sb->s_blocksize - 1)) + 1; brelse(bh); goto bail; } offset += le16_to_cpu(de->rec_len); if (le64_to_cpu(de->inode)) { /* We might block in the next section * if the data destination is * currently swapped out. So, use a * version stamp to detect whether or * not the directory has been modified * during the copy operation. */ unsigned long version = filp->f_version; unsigned char d_type = DT_UNKNOWN; if (de->file_type < OCFS2_FT_MAX) d_type = ocfs2_filetype_table[de->file_type]; error = filldir(dirent, de->name, de->name_len, filp->f_pos, ino_from_blkno(sb, le64_to_cpu(de->inode)), d_type); if (error) break; if (version != filp->f_version) goto revalidate; stored ++; } filp->f_pos += le16_to_cpu(de->rec_len); } offset = 0; brelse(bh); } stored = 0; bail: ocfs2_meta_unlock(inode, 0); bail_nolock: mlog_exit(stored); return stored; } /* * NOTE: this should always be called with parent dir i_mutex taken. */ int ocfs2_find_files_on_disk(const char *name, int namelen, u64 *blkno, struct inode *inode, struct buffer_head **dirent_bh, struct ocfs2_dir_entry **dirent) { int status = -ENOENT; mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n", namelen, name, blkno, inode, dirent_bh, dirent); *dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent); if (!*dirent_bh || !*dirent) { status = -ENOENT; goto leave; } *blkno = le64_to_cpu((*dirent)->inode); status = 0; leave: if (status < 0) { *dirent = NULL; if (*dirent_bh) { brelse(*dirent_bh); *dirent_bh = NULL; } } mlog_exit(status); return status; } /* Check for a name within a directory. * * Return 0 if the name does not exist * Return -EEXIST if the directory contains the name * * Callers should have i_mutex + a cluster lock on dir */ int ocfs2_check_dir_for_entry(struct inode *dir, const char *name, int namelen) { int ret; struct buffer_head *dirent_bh = NULL; struct ocfs2_dir_entry *dirent = NULL; mlog_entry("dir %llu, name '%.*s'\n", (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name); ret = -EEXIST; dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent); if (dirent_bh) goto bail; ret = 0; bail: if (dirent_bh) brelse(dirent_bh); mlog_exit(ret); return ret; } /* * routine to check that the specified directory is empty (for rmdir) */ int ocfs2_empty_dir(struct inode *inode) { unsigned long offset; struct buffer_head * bh; struct ocfs2_dir_entry * de, * de1; struct super_block * sb; int err; sb = inode->i_sb; if ((i_size_read(inode) < (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) || !(bh = ocfs2_bread(inode, 0, &err, 0))) { mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); return 1; } de = (struct ocfs2_dir_entry *) bh->b_data; de1 = (struct ocfs2_dir_entry *) ((char *)de + le16_to_cpu(de->rec_len)); if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) || !le64_to_cpu(de1->inode) || strcmp(".", de->name) || strcmp("..", de1->name)) { mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); brelse(bh); return 1; } offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len); de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len)); while (offset < i_size_read(inode) ) { if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) { brelse(bh); bh = ocfs2_bread(inode, offset >> sb->s_blocksize_bits, &err, 0); if (!bh) { mlog(ML_ERROR, "dir %llu has a hole at %lu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno, offset); offset += sb->s_blocksize; continue; } de = (struct ocfs2_dir_entry *) bh->b_data; } if (!ocfs2_check_dir_entry(inode, de, bh, offset)) { brelse(bh); return 1; } if (le64_to_cpu(de->inode)) { brelse(bh); return 0; } offset += le16_to_cpu(de->rec_len); de = (struct ocfs2_dir_entry *) ((char *)de + le16_to_cpu(de->rec_len)); } brelse(bh); return 1; } /* returns a bh of the 1st new block in the allocation. */ int ocfs2_do_extend_dir(struct super_block *sb, struct ocfs2_journal_handle *handle, struct inode *dir, struct buffer_head *parent_fe_bh, struct ocfs2_alloc_context *data_ac, struct ocfs2_alloc_context *meta_ac, struct buffer_head **new_bh) { int status; int extend; u64 p_blkno; spin_lock(&OCFS2_I(dir)->ip_lock); extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)); spin_unlock(&OCFS2_I(dir)->ip_lock); if (extend) { status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1, parent_fe_bh, handle, data_ac, meta_ac, NULL); BUG_ON(status == -EAGAIN); if (status < 0) { mlog_errno(status); goto bail; } } status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >> (sb->s_blocksize_bits - 9)), 1, &p_blkno, NULL); if (status < 0) { mlog_errno(status); goto bail; } *new_bh = sb_getblk(sb, p_blkno); if (!*new_bh) { status = -EIO; mlog_errno(status); goto bail; } status = 0; bail: mlog_exit(status); return status; } /* assumes you already have a cluster lock on the directory. */ static int ocfs2_extend_dir(struct ocfs2_super *osb, struct inode *dir, struct buffer_head *parent_fe_bh, struct buffer_head **new_de_bh) { int status = 0; int credits, num_free_extents; loff_t dir_i_size; struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; struct ocfs2_alloc_context *data_ac = NULL; struct ocfs2_alloc_context *meta_ac = NULL; struct ocfs2_journal_handle *handle = NULL; struct buffer_head *new_bh = NULL; struct ocfs2_dir_entry * de; struct super_block *sb = osb->sb; mlog_entry_void(); dir_i_size = i_size_read(dir); mlog(0, "extending dir %llu (i_size = %lld)\n", (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size); handle = ocfs2_alloc_handle(osb); if (handle == NULL) { status = -ENOMEM; mlog_errno(status); goto bail; } /* dir->i_size is always block aligned. */ spin_lock(&OCFS2_I(dir)->ip_lock); if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) { spin_unlock(&OCFS2_I(dir)->ip_lock); num_free_extents = ocfs2_num_free_extents(osb, dir, fe); if (num_free_extents < 0) { status = num_free_extents; mlog_errno(status); goto bail; } if (!num_free_extents) { status = ocfs2_reserve_new_metadata(osb, handle, fe, &meta_ac); if (status < 0) { if (status != -ENOSPC) mlog_errno(status); goto bail; } } status = ocfs2_reserve_clusters(osb, handle, 1, &data_ac); if (status < 0) { if (status != -ENOSPC) mlog_errno(status); goto bail; } credits = ocfs2_calc_extend_credits(sb, fe, 1); } else { spin_unlock(&OCFS2_I(dir)->ip_lock); credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS; } handle = ocfs2_start_trans(osb, handle, credits); if (IS_ERR(handle)) { status = PTR_ERR(handle); handle = NULL; mlog_errno(status); goto bail; } status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh, data_ac, meta_ac, &new_bh); if (status < 0) { mlog_errno(status); goto bail; } ocfs2_set_new_buffer_uptodate(dir, new_bh); status = ocfs2_journal_access(handle, dir, new_bh, OCFS2_JOURNAL_ACCESS_CREATE); if (status < 0) { mlog_errno(status); goto bail; } memset(new_bh->b_data, 0, sb->s_blocksize); de = (struct ocfs2_dir_entry *) new_bh->b_data; de->inode = 0; de->rec_len = cpu_to_le16(sb->s_blocksize); status = ocfs2_journal_dirty(handle, new_bh); if (status < 0) { mlog_errno(status); goto bail; } dir_i_size += dir->i_sb->s_blocksize; i_size_write(dir, dir_i_size); dir->i_blocks = ocfs2_align_bytes_to_sectors(dir_i_size); status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh); if (status < 0) { mlog_errno(status); goto bail; } *new_de_bh = new_bh; get_bh(*new_de_bh); bail: if (handle) ocfs2_commit_trans(handle); if (data_ac) ocfs2_free_alloc_context(data_ac); if (meta_ac) ocfs2_free_alloc_context(meta_ac); if (new_bh) brelse(new_bh); mlog_exit(status); return status; } /* * Search the dir for a good spot, extending it if necessary. The * block containing an appropriate record is returned in ret_de_bh. */ int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb, struct inode *dir, struct buffer_head *parent_fe_bh, const char *name, int namelen, struct buffer_head **ret_de_bh) { unsigned long offset; struct buffer_head * bh = NULL; unsigned short rec_len; struct ocfs2_dinode *fe; struct ocfs2_dir_entry *de; struct super_block *sb; int status; mlog_entry_void(); mlog(0, "getting ready to insert namelen %d into dir %llu\n", namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno); BUG_ON(!S_ISDIR(dir->i_mode)); fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir)); sb = dir->i_sb; if (!namelen) { status = -EINVAL; mlog_errno(status); goto bail; } bh = ocfs2_bread(dir, 0, &status, 0); if (!bh) { mlog_errno(status); goto bail; } rec_len = OCFS2_DIR_REC_LEN(namelen); offset = 0; de = (struct ocfs2_dir_entry *) bh->b_data; while (1) { if ((char *)de >= sb->s_blocksize + bh->b_data) { brelse(bh); bh = NULL; if (i_size_read(dir) <= offset) { status = ocfs2_extend_dir(osb, dir, parent_fe_bh, &bh); if (status < 0) { mlog_errno(status); goto bail; } BUG_ON(!bh); *ret_de_bh = bh; get_bh(*ret_de_bh); goto bail; } bh = ocfs2_bread(dir, offset >> sb->s_blocksize_bits, &status, 0); if (!bh) { mlog_errno(status); goto bail; } /* move to next block */ de = (struct ocfs2_dir_entry *) bh->b_data; } if (!ocfs2_check_dir_entry(dir, de, bh, offset)) { status = -ENOENT; goto bail; } if (ocfs2_match(namelen, name, de)) { status = -EEXIST; goto bail; } if (((le64_to_cpu(de->inode) == 0) && (le16_to_cpu(de->rec_len) >= rec_len)) || (le16_to_cpu(de->rec_len) >= (OCFS2_DIR_REC_LEN(de->name_len) + rec_len))) { /* Ok, we found a spot. Return this bh and let * the caller actually fill it in. */ *ret_de_bh = bh; get_bh(*ret_de_bh); status = 0; goto bail; } offset += le16_to_cpu(de->rec_len); de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len)); } status = 0; bail: if (bh) brelse(bh); mlog_exit(status); return status; }