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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ufs/dir.c | |
download | kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/ufs/dir.c')
-rw-r--r-- | fs/ufs/dir.c | 627 |
1 files changed, 627 insertions, 0 deletions
diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c new file mode 100644 index 0000000..d0915fb --- /dev/null +++ b/fs/ufs/dir.c @@ -0,0 +1,627 @@ +/* + * 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), + fs16to_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, +}; |