/* * linux/fs/ufs/ufs_dir.c * * Copyright (C) 1996 * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu) * Laboratory for Computer Science Research Computing Facility * Rutgers, The State University of New Jersey * * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406 * * 4.4BSD (FreeBSD) support added on February 1st 1998 by * Niels Kristian Bech Jensen <nkbj@image.dk> partially based * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>. */ #include <linux/time.h> #include <linux/fs.h> #include <linux/ufs_fs.h> #include <linux/smp_lock.h> #include <linux/buffer_head.h> #include <linux/sched.h> #include "swab.h" #include "util.h" #undef UFS_DIR_DEBUG #ifdef UFS_DIR_DEBUG #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x; #else #define UFSD(x) #endif static int ufs_check_dir_entry (const char *, struct inode *, struct ufs_dir_entry *, struct buffer_head *, unsigned long); /* * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure. * * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller. */ static inline int ufs_match(struct super_block *sb, int len, const char * const name, struct ufs_dir_entry * de) { if (len != ufs_get_de_namlen(sb, de)) return 0; if (!de->d_ino) return 0; return !memcmp(name, de->d_name, len); } /* * This is blatantly stolen from ext2fs */ static int ufs_readdir (struct file * filp, void * dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; int error = 0; unsigned long offset, lblk; int i, stored; struct buffer_head * bh; struct ufs_dir_entry * de; struct super_block * sb; int de_reclen; unsigned flags; u64 blk= 0L; lock_kernel(); sb = inode->i_sb; flags = UFS_SB(sb)->s_flags; UFSD(("ENTER, ino %lu f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos)) stored = 0; bh = NULL; offset = filp->f_pos & (sb->s_blocksize - 1); while (!error && !stored && filp->f_pos < inode->i_size) { lblk = (filp->f_pos) >> sb->s_blocksize_bits; blk = ufs_frag_map(inode, lblk); if (!blk || !(bh = sb_bread(sb, blk))) { /* XXX - error - skip to the next block */ printk("ufs_readdir: " "dir inode %lu has a hole at offset %lu\n", inode->i_ino, (unsigned long int)filp->f_pos); filp->f_pos += sb->s_blocksize - offset; continue; } 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 ufs_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. */ de_reclen = fs16_to_cpu(sb, de->d_reclen); if (de_reclen < 1) break; i += de_reclen; } offset = i; filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) | offset; filp->f_version = inode->i_version; } while (!error && filp->f_pos < inode->i_size && offset < sb->s_blocksize) { de = (struct ufs_dir_entry *) (bh->b_data + offset); /* XXX - put in a real ufs_check_dir_entry() */ if ((de->d_reclen == 0) || (ufs_get_de_namlen(sb, de) == 0)) { filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1)) + sb->s_blocksize; brelse(bh); unlock_kernel(); return stored; } if (!ufs_check_dir_entry ("ufs_readdir", 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); unlock_kernel(); return stored; } offset += fs16_to_cpu(sb, de->d_reclen); if (de->d_ino) { /* 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; UFSD(("filldir(%s,%u)\n", de->d_name, fs32_to_cpu(sb, de->d_ino))) UFSD(("namlen %u\n", ufs_get_de_namlen(sb, de))) if ((flags & UFS_DE_MASK) == UFS_DE_44BSD) d_type = de->d_u.d_44.d_type; error = filldir(dirent, de->d_name, ufs_get_de_namlen(sb, de), filp->f_pos, fs32_to_cpu(sb, de->d_ino), d_type); if (error) break; if (version != filp->f_version) goto revalidate; stored ++; } filp->f_pos += fs16_to_cpu(sb, de->d_reclen); } offset = 0; brelse (bh); } unlock_kernel(); return 0; } /* * define how far ahead to read directories while searching them. */ #define NAMEI_RA_CHUNKS 2 #define NAMEI_RA_BLOCKS 4 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) #define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b)) /* * ufs_find_entry() * * finds an entry in the specified directory with the wanted name. It * returns the cache buffer in which the entry was found, and the entry * itself (as a parameter - res_bh). It does NOT read the inode of the * entry - you'll have to do that yourself if you want to. */ struct ufs_dir_entry * ufs_find_entry (struct dentry *dentry, struct buffer_head ** res_bh) { struct super_block * sb; struct buffer_head * bh_use[NAMEI_RA_SIZE]; struct buffer_head * bh_read[NAMEI_RA_SIZE]; unsigned long offset; int block, toread, i, err; struct inode *dir = dentry->d_parent->d_inode; const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; UFSD(("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen)) *res_bh = NULL; sb = dir->i_sb; if (namelen > UFS_MAXNAMLEN) return NULL; memset (bh_use, 0, sizeof (bh_use)); toread = 0; for (block = 0; block < NAMEI_RA_SIZE; ++block) { struct buffer_head * bh; if ((block << sb->s_blocksize_bits) >= dir->i_size) break; bh = ufs_getfrag (dir, block, 0, &err); bh_use[block] = bh; if (bh && !buffer_uptodate(bh)) bh_read[toread++] = bh; } for (block = 0, offset = 0; offset < dir->i_size; block++) { struct buffer_head * bh; struct ufs_dir_entry * de; char * dlimit; if ((block % NAMEI_RA_BLOCKS) == 0 && toread) { ll_rw_block (READ, toread, bh_read); toread = 0; } bh = bh_use[block % NAMEI_RA_SIZE]; if (!bh) { ufs_error (sb, "ufs_find_entry", "directory #%lu contains a hole at offset %lu", dir->i_ino, offset); offset += sb->s_blocksize; continue; } wait_on_buffer (bh); if (!buffer_uptodate(bh)) { /* * read error: all bets are off */ break; } de = (struct ufs_dir_entry *) bh->b_data; dlimit = bh->b_data + sb->s_blocksize; while ((char *) de < dlimit && offset < dir->i_size) { /* this code is executed quadratically often */ /* do minimal checking by hand */ int de_len; if ((char *) de + namelen <= dlimit && ufs_match(sb, namelen, name, de)) { /* found a match - just to be sure, do a full check */ if (!ufs_check_dir_entry("ufs_find_entry", dir, de, bh, offset)) goto failed; for (i = 0; i < NAMEI_RA_SIZE; ++i) { if (bh_use[i] != bh) brelse (bh_use[i]); } *res_bh = bh; return de; } /* prevent looping on a bad block */ de_len = fs16_to_cpu(sb, de->d_reclen); if (de_len <= 0) goto failed; offset += de_len; de = (struct ufs_dir_entry *) ((char *) de + de_len); } brelse (bh); if (((block + NAMEI_RA_SIZE) << sb->s_blocksize_bits ) >= dir->i_size) bh = NULL; else bh = ufs_getfrag (dir, block + NAMEI_RA_SIZE, 0, &err); bh_use[block % NAMEI_RA_SIZE] = bh; if (bh && !buffer_uptodate(bh)) bh_read[toread++] = bh; } failed: for (i = 0; i < NAMEI_RA_SIZE; ++i) brelse (bh_use[i]); UFSD(("EXIT\n")) return NULL; } static int ufs_check_dir_entry (const char *function, struct inode *dir, struct ufs_dir_entry *de, struct buffer_head *bh, unsigned long offset) { struct super_block *sb = dir->i_sb; const char *error_msg = NULL; int rlen = fs16_to_cpu(sb, de->d_reclen); if (rlen < UFS_DIR_REC_LEN(1)) error_msg = "reclen is smaller than minimal"; else if (rlen % 4 != 0) error_msg = "reclen % 4 != 0"; else if (rlen < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de))) error_msg = "reclen is too small for namlen"; else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize) error_msg = "directory entry across blocks"; else if (fs32_to_cpu(sb, de->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg * UFS_SB(sb)->s_uspi->s_ncg)) error_msg = "inode out of bounds"; if (error_msg != NULL) ufs_error (sb, function, "bad entry in directory #%lu, size %Lu: %s - " "offset=%lu, inode=%lu, reclen=%d, namlen=%d", dir->i_ino, dir->i_size, error_msg, offset, (unsigned long)fs32_to_cpu(sb, de->d_ino), rlen, ufs_get_de_namlen(sb, de)); return (error_msg == NULL ? 1 : 0); } struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct buffer_head **p) { int err; struct buffer_head *bh = ufs_bread (dir, 0, 0, &err); struct ufs_dir_entry *res = NULL; if (bh) { res = (struct ufs_dir_entry *) bh->b_data; res = (struct ufs_dir_entry *)((char *)res + fs16_to_cpu(dir->i_sb, res->d_reclen)); } *p = bh; return res; } ino_t ufs_inode_by_name(struct inode * dir, struct dentry *dentry) { ino_t res = 0; struct ufs_dir_entry * de; struct buffer_head *bh; de = ufs_find_entry (dentry, &bh); if (de) { res = fs32_to_cpu(dir->i_sb, de->d_ino); brelse(bh); } return res; } void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de, struct buffer_head *bh, struct inode *inode) { dir->i_version++; de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino); mark_buffer_dirty(bh); if (IS_DIRSYNC(dir)) sync_dirty_buffer(bh); brelse (bh); } /* * ufs_add_entry() * * adds a file entry to the specified directory, using the same * semantics as ufs_find_entry(). It returns NULL if it failed. */ int ufs_add_link(struct dentry *dentry, struct inode *inode) { struct super_block * sb; struct ufs_sb_private_info * uspi; unsigned long offset; unsigned fragoff; unsigned short rec_len; struct buffer_head * bh; struct ufs_dir_entry * de, * de1; struct inode *dir = dentry->d_parent->d_inode; const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; int err; UFSD(("ENTER, name %s, namelen %u\n", name, namelen)) sb = dir->i_sb; uspi = UFS_SB(sb)->s_uspi; if (!namelen) return -EINVAL; bh = ufs_bread (dir, 0, 0, &err); if (!bh) return err; rec_len = UFS_DIR_REC_LEN(namelen); offset = 0; de = (struct ufs_dir_entry *) bh->b_data; while (1) { if ((char *)de >= UFS_SECTOR_SIZE + bh->b_data) { fragoff = offset & ~uspi->s_fmask; if (fragoff != 0 && fragoff != UFS_SECTOR_SIZE) ufs_error (sb, "ufs_add_entry", "internal error" " fragoff %u", fragoff); if (!fragoff) { brelse (bh); bh = ufs_bread (dir, offset >> sb->s_blocksize_bits, 1, &err); if (!bh) return err; } if (dir->i_size <= offset) { if (dir->i_size == 0) { brelse(bh); return -ENOENT; } de = (struct ufs_dir_entry *) (bh->b_data + fragoff); de->d_ino = 0; de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE); ufs_set_de_namlen(sb, de, 0); dir->i_size = offset + UFS_SECTOR_SIZE; mark_inode_dirty(dir); } else { de = (struct ufs_dir_entry *) bh->b_data; } } if (!ufs_check_dir_entry ("ufs_add_entry", dir, de, bh, offset)) { brelse (bh); return -ENOENT; } if (ufs_match(sb, namelen, name, de)) { brelse (bh); return -EEXIST; } if (de->d_ino == 0 && fs16_to_cpu(sb, de->d_reclen) >= rec_len) break; if (fs16_to_cpu(sb, de->d_reclen) >= UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)) + rec_len) break; offset += fs16_to_cpu(sb, de->d_reclen); de = (struct ufs_dir_entry *) ((char *) de + fs16_to_cpu(sb, de->d_reclen)); } if (de->d_ino) { de1 = (struct ufs_dir_entry *) ((char *) de + UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de))); de1->d_reclen = cpu_to_fs16(sb, fs16_to_cpu(sb, de->d_reclen) - UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de))); de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de))); de = de1; } de->d_ino = 0; ufs_set_de_namlen(sb, de, namelen); memcpy (de->d_name, name, namelen + 1); de->d_ino = cpu_to_fs32(sb, inode->i_ino); ufs_set_de_type(sb, de, inode->i_mode); mark_buffer_dirty(bh); if (IS_DIRSYNC(dir)) sync_dirty_buffer(bh); brelse (bh); dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC; dir->i_version++; mark_inode_dirty(dir); UFSD(("EXIT\n")) return 0; } /* * ufs_delete_entry deletes a directory entry by merging it with the * previous entry. */ int ufs_delete_entry (struct inode * inode, struct ufs_dir_entry * dir, struct buffer_head * bh ) { struct super_block * sb; struct ufs_dir_entry * de, * pde; unsigned i; UFSD(("ENTER\n")) sb = inode->i_sb; i = 0; pde = NULL; de = (struct ufs_dir_entry *) bh->b_data; UFSD(("ino %u, reclen %u, namlen %u, name %s\n", fs32_to_cpu(sb, de->d_ino), fs16_to_cpu(sb, de->d_reclen), ufs_get_de_namlen(sb, de), de->d_name)) while (i < bh->b_size) { if (!ufs_check_dir_entry ("ufs_delete_entry", inode, de, bh, i)) { brelse(bh); return -EIO; } if (de == dir) { if (pde) fs16_add(sb, &pde->d_reclen, fs16_to_cpu(sb, dir->d_reclen)); dir->d_ino = 0; inode->i_version++; inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; mark_inode_dirty(inode); mark_buffer_dirty(bh); if (IS_DIRSYNC(inode)) sync_dirty_buffer(bh); brelse(bh); UFSD(("EXIT\n")) return 0; } i += fs16_to_cpu(sb, de->d_reclen); if (i == UFS_SECTOR_SIZE) pde = NULL; else pde = de; de = (struct ufs_dir_entry *) ((char *) de + fs16_to_cpu(sb, de->d_reclen)); if (i == UFS_SECTOR_SIZE && de->d_reclen == 0) break; } UFSD(("EXIT\n")) brelse(bh); return -ENOENT; } int ufs_make_empty(struct inode * inode, struct inode *dir) { struct super_block * sb = dir->i_sb; struct buffer_head * dir_block; struct ufs_dir_entry * de; int err; dir_block = ufs_bread (inode, 0, 1, &err); if (!dir_block) return err; inode->i_blocks = sb->s_blocksize / UFS_SECTOR_SIZE; de = (struct ufs_dir_entry *) dir_block->b_data; de->d_ino = cpu_to_fs32(sb, inode->i_ino); ufs_set_de_type(sb, de, inode->i_mode); ufs_set_de_namlen(sb, de, 1); de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1)); strcpy (de->d_name, "."); de = (struct ufs_dir_entry *) ((char *)de + fs16_to_cpu(sb, de->d_reclen)); de->d_ino = cpu_to_fs32(sb, dir->i_ino); ufs_set_de_type(sb, de, dir->i_mode); de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE - UFS_DIR_REC_LEN(1)); ufs_set_de_namlen(sb, de, 2); strcpy (de->d_name, ".."); mark_buffer_dirty(dir_block); brelse (dir_block); mark_inode_dirty(inode); return 0; } /* * routine to check that the specified directory is empty (for rmdir) */ int ufs_empty_dir (struct inode * inode) { struct super_block * sb; unsigned long offset; struct buffer_head * bh; struct ufs_dir_entry * de, * de1; int err; sb = inode->i_sb; if (inode->i_size < UFS_DIR_REC_LEN(1) + UFS_DIR_REC_LEN(2) || !(bh = ufs_bread (inode, 0, 0, &err))) { ufs_warning (inode->i_sb, "empty_dir", "bad directory (dir #%lu) - no data block", inode->i_ino); return 1; } de = (struct ufs_dir_entry *) bh->b_data; de1 = (struct ufs_dir_entry *) ((char *)de + fs16_to_cpu(sb, de->d_reclen)); if (fs32_to_cpu(sb, de->d_ino) != inode->i_ino || de1->d_ino == 0 || strcmp (".", de->d_name) || strcmp ("..", de1->d_name)) { ufs_warning (inode->i_sb, "empty_dir", "bad directory (dir #%lu) - no `.' or `..'", inode->i_ino); return 1; } offset = fs16_to_cpu(sb, de->d_reclen) + fs16_to_cpu(sb, de1->d_reclen); de = (struct ufs_dir_entry *) ((char *)de1 + fs16_to_cpu(sb, de1->d_reclen)); while (offset < inode->i_size ) { if (!bh || (void *) de >= (void *) (bh->b_data + sb->s_blocksize)) { brelse (bh); bh = ufs_bread (inode, offset >> sb->s_blocksize_bits, 1, &err); if (!bh) { ufs_error (sb, "empty_dir", "directory #%lu contains a hole at offset %lu", inode->i_ino, offset); offset += sb->s_blocksize; continue; } de = (struct ufs_dir_entry *) bh->b_data; } if (!ufs_check_dir_entry ("empty_dir", inode, de, bh, offset)) { brelse (bh); return 1; } if (de->d_ino) { brelse (bh); return 0; } offset += fs16_to_cpu(sb, de->d_reclen); de = (struct ufs_dir_entry *) ((char *)de + fs16_to_cpu(sb, de->d_reclen)); } brelse (bh); return 1; } struct file_operations ufs_dir_operations = { .read = generic_read_dir, .readdir = ufs_readdir, .fsync = file_fsync, };