[linux.git] / fs / ufs / ialloc.c

/*
 *  linux/fs/ufs/ialloc.c
 *
 * Copyright (c) 1998
 * Daniel Pirkl <[email protected]>
 * Charles University, Faculty of Mathematics and Physics
 *
 *  from
 *
 *  linux/fs/ext2/ialloc.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card ([email protected])
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  BSD ufs-inspired inode and directory allocation by 
 *  Stephen Tweedie ([email protected]), 1993
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller ([email protected]), 1995
 */

#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/sched.h>
#include <linux/bitops.h>
#include <asm/byteorder.h>

#include "swab.h"
#include "util.h"

/*
 * NOTE! When we get the inode, we're the only people
 * that have access to it, and as such there are no
 * race conditions we have to worry about. The inode
 * is not on the hash-lists, and it cannot be reached
 * through the filesystem because the directory entry
 * has been deleted earlier.
 *
 * HOWEVER: we must make sure that we get no aliases,
 * which means that we have to call "clear_inode()"
 * _before_ we mark the inode not in use in the inode
 * bitmaps. Otherwise a newly created file might use
 * the same inode number (not actually the same pointer
 * though), and then we'd have two inodes sharing the
 * same inode number and space on the harddisk.
 */
void ufs_free_inode (struct inode * inode)
{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_super_block_first * usb1;
	struct ufs_cg_private_info * ucpi;
	struct ufs_cylinder_group * ucg;
	int is_directory;
	unsigned ino, cg, bit;
	
	UFSD("ENTER, ino %lu\n", inode->i_ino);

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;
	usb1 = ubh_get_usb_first(uspi);
	
	ino = inode->i_ino;

	lock_super (sb);

	if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
		ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
		unlock_super (sb);
		return;
	}
	
	cg = ufs_inotocg (ino);
	bit = ufs_inotocgoff (ino);
	ucpi = ufs_load_cylinder (sb, cg);
	if (!ucpi) {
		unlock_super (sb);
		return;
	}
	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
	if (!ufs_cg_chkmagic(sb, ucg))
		ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");

	ucg->cg_time = cpu_to_fs32(sb, get_seconds());

	is_directory = S_ISDIR(inode->i_mode);

	DQUOT_FREE_INODE(inode);
	DQUOT_DROP(inode);

	clear_inode (inode);

	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
		ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
	else {
		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
		if (ino < ucpi->c_irotor)
			ucpi->c_irotor = ino;
		fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
		uspi->cs_total.cs_nifree++;
		fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);

		if (is_directory) {
			fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
			uspi->cs_total.cs_ndir--;
			fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
		}
	}

	ubh_mark_buffer_dirty (USPI_UBH(uspi));
	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
	if (sb->s_flags & MS_SYNCHRONOUS) {
		ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
		ubh_wait_on_buffer (UCPI_UBH(ucpi));
	}
	
	sb->s_dirt = 1;
	unlock_super (sb);
	UFSD("EXIT\n");
}

/*
 * There are two policies for allocating an inode.  If the new inode is
 * a directory, then a forward search is made for a block group with both
 * free space and a low directory-to-inode ratio; if that fails, then of
 * the groups with above-average free space, that group with the fewest
 * directories already is chosen.
 *
 * For other inodes, search forward from the parent directory's block
 * group to find a free inode.
 */
struct inode * ufs_new_inode(struct inode * dir, int mode)
{
	struct super_block * sb;
	struct ufs_sb_info * sbi;
	struct ufs_sb_private_info * uspi;
	struct ufs_super_block_first * usb1;
	struct ufs_cg_private_info * ucpi;
	struct ufs_cylinder_group * ucg;
	struct inode * inode;
	unsigned cg, bit, i, j, start;
	struct ufs_inode_info *ufsi;

	UFSD("ENTER\n");
	
	/* Cannot create files in a deleted directory */
	if (!dir || !dir->i_nlink)
		return ERR_PTR(-EPERM);
	sb = dir->i_sb;
	inode = new_inode(sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	ufsi = UFS_I(inode);
	sbi = UFS_SB(sb);
	uspi = sbi->s_uspi;
	usb1 = ubh_get_usb_first(uspi);

	lock_super (sb);

	/*
	 * Try to place the inode in its parent directory
	 */
	i = ufs_inotocg(dir->i_ino);
	if (sbi->fs_cs(i).cs_nifree) {
		cg = i;
		goto cg_found;
	}

	/*
	 * Use a quadratic hash to find a group with a free inode
	 */
	for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
		i += j;
		if (i >= uspi->s_ncg)
			i -= uspi->s_ncg;
		if (sbi->fs_cs(i).cs_nifree) {
			cg = i;
			goto cg_found;
		}
	}

	/*
	 * That failed: try linear search for a free inode
	 */
	i = ufs_inotocg(dir->i_ino) + 1;
	for (j = 2; j < uspi->s_ncg; j++) {
		i++;
		if (i >= uspi->s_ncg)
			i = 0;
		if (sbi->fs_cs(i).cs_nifree) {
			cg = i;
			goto cg_found;
		}
	}
	
	goto failed;

cg_found:
	ucpi = ufs_load_cylinder (sb, cg);
	if (!ucpi)
		goto failed;
	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
	if (!ufs_cg_chkmagic(sb, ucg)) 
		ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");

	start = ucpi->c_irotor;
	bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
	if (!(bit < uspi->s_ipg)) {
		bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
		if (!(bit < start)) {
			ufs_error (sb, "ufs_new_inode",
			    "cylinder group %u corrupted - error in inode bitmap\n", cg);
			goto failed;
		}
	}
	UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
		ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
	else {
		ufs_panic (sb, "ufs_new_inode", "internal error");
		goto failed;
	}
	
	fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
	uspi->cs_total.cs_nifree--;
	fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
	
	if (S_ISDIR(mode)) {
		fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
		uspi->cs_total.cs_ndir++;
		fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
	}

	ubh_mark_buffer_dirty (USPI_UBH(uspi));
	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
	if (sb->s_flags & MS_SYNCHRONOUS) {
		ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
		ubh_wait_on_buffer (UCPI_UBH(ucpi));
	}
	sb->s_dirt = 1;

	inode->i_mode = mode;
	inode->i_uid = current->fsuid;
	if (dir->i_mode & S_ISGID) {
		inode->i_gid = dir->i_gid;
		if (S_ISDIR(mode))
			inode->i_mode |= S_ISGID;
	} else
		inode->i_gid = current->fsgid;

	inode->i_ino = cg * uspi->s_ipg + bit;
	inode->i_blocks = 0;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	ufsi->i_flags = UFS_I(dir)->i_flags;
	ufsi->i_lastfrag = 0;
	ufsi->i_gen = 0;
	ufsi->i_shadow = 0;
	ufsi->i_osync = 0;
	ufsi->i_oeftflag = 0;
	ufsi->i_dir_start_lookup = 0;
	memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));

	insert_inode_hash(inode);
	mark_inode_dirty(inode);

	unlock_super (sb);

	if (DQUOT_ALLOC_INODE(inode)) {
		DQUOT_DROP(inode);
		inode->i_flags |= S_NOQUOTA;
		inode->i_nlink = 0;
		iput(inode);
		return ERR_PTR(-EDQUOT);
	}

	UFSD("allocating inode %lu\n", inode->i_ino);
	UFSD("EXIT\n");
	return inode;

failed:
	unlock_super (sb);
	make_bad_inode(inode);
	iput (inode);
	UFSD("EXIT (FAILED)\n");
	return ERR_PTR(-ENOSPC);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/ufs/ialloc.c
	3	*
	4	* Copyright (c) 1998
	5	* Daniel Pirkl <[email protected]>
	6	* Charles University, Faculty of Mathematics and Physics
	7	*
	8	* from
	9	*
	10	* linux/fs/ext2/ialloc.c
	11	*
	12	* Copyright (C) 1992, 1993, 1994, 1995
	13	* Remy Card ([email protected])
	14	* Laboratoire MASI - Institut Blaise Pascal
	15	* Universite Pierre et Marie Curie (Paris VI)
	16	*
	17	* BSD ufs-inspired inode and directory allocation by
	18	* Stephen Tweedie ([email protected]), 1993
	19	* Big-endian to little-endian byte-swapping/bitmaps by
	20	* David S. Miller ([email protected]), 1995
	21	*/
	22
	23	#include <linux/fs.h>
	24	#include <linux/ufs_fs.h>
	25	#include <linux/time.h>
	26	#include <linux/stat.h>
	27	#include <linux/string.h>
	28	#include <linux/quotaops.h>
	29	#include <linux/buffer_head.h>
	30	#include <linux/sched.h>
	31	#include <linux/bitops.h>
	32	#include <asm/byteorder.h>
	33
	34	#include "swab.h"
	35	#include "util.h"
	36
1da177e4 LT	37	/*
	38	* NOTE! When we get the inode, we're the only people
	39	* that have access to it, and as such there are no
	40	* race conditions we have to worry about. The inode
	41	* is not on the hash-lists, and it cannot be reached
	42	* through the filesystem because the directory entry
	43	* has been deleted earlier.
	44	*
	45	* HOWEVER: we must make sure that we get no aliases,
	46	* which means that we have to call "clear_inode()"
	47	* _before_ we mark the inode not in use in the inode
	48	* bitmaps. Otherwise a newly created file might use
	49	* the same inode number (not actually the same pointer
	50	* though), and then we'd have two inodes sharing the
	51	* same inode number and space on the harddisk.
	52	*/
	53	void ufs_free_inode (struct inode * inode)
	54	{
	55	struct super_block * sb;
	56	struct ufs_sb_private_info * uspi;
	57	struct ufs_super_block_first * usb1;
	58	struct ufs_cg_private_info * ucpi;
	59	struct ufs_cylinder_group * ucg;
	60	int is_directory;
	61	unsigned ino, cg, bit;
	62
abf5d15f	63	UFSD("ENTER, ino %lu\n", inode->i_ino);
1da177e4 LT	64
	65	sb = inode->i_sb;
	66	uspi = UFS_SB(sb)->s_uspi;
7b4ee73e	67	usb1 = ubh_get_usb_first(uspi);
1da177e4 LT	68
	69	ino = inode->i_ino;
	70
	71	lock_super (sb);
	72
	73	if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
	74	ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
	75	unlock_super (sb);
	76	return;
	77	}
	78
	79	cg = ufs_inotocg (ino);
	80	bit = ufs_inotocgoff (ino);
	81	ucpi = ufs_load_cylinder (sb, cg);
	82	if (!ucpi) {
	83	unlock_super (sb);
	84	return;
	85	}
9695ef16	86	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
1da177e4 LT	87	if (!ufs_cg_chkmagic(sb, ucg))
	88	ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
	89
	90	ucg->cg_time = cpu_to_fs32(sb, get_seconds());
	91
	92	is_directory = S_ISDIR(inode->i_mode);
	93
	94	DQUOT_FREE_INODE(inode);
	95	DQUOT_DROP(inode);
	96
	97	clear_inode (inode);
	98
9695ef16	99	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
1da177e4 LT	100	ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
1da177e4 LT	101	else {
9695ef16	102	ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
1da177e4 LT	103	if (ino < ucpi->c_irotor)
	104	ucpi->c_irotor = ino;
	105	fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
ee3ffd6c	106	uspi->cs_total.cs_nifree++;
1da177e4 LT	107	fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
	108
	109	if (is_directory) {
	110	fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
ee3ffd6c	111	uspi->cs_total.cs_ndir--;
1da177e4 LT	112	fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
	113	}
	114	}
	115
9695ef16 ED	116	ubh_mark_buffer_dirty (USPI_UBH(uspi));
9695ef16 ED	117	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
1da177e4	118	if (sb->s_flags & MS_SYNCHRONOUS) {
098d5af7	119	ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
9695ef16	120	ubh_wait_on_buffer (UCPI_UBH(ucpi));
1da177e4 LT	121	}
	122
	123	sb->s_dirt = 1;
	124	unlock_super (sb);
abf5d15f	125	UFSD("EXIT\n");
1da177e4 LT	126	}
	127
	128	/*
	129	* There are two policies for allocating an inode. If the new inode is
	130	* a directory, then a forward search is made for a block group with both
	131	* free space and a low directory-to-inode ratio; if that fails, then of
	132	* the groups with above-average free space, that group with the fewest
	133	* directories already is chosen.
	134	*
	135	* For other inodes, search forward from the parent directory's block
	136	* group to find a free inode.
	137	*/
	138	struct inode * ufs_new_inode(struct inode * dir, int mode)
	139	{
	140	struct super_block * sb;
	141	struct ufs_sb_info * sbi;
	142	struct ufs_sb_private_info * uspi;
	143	struct ufs_super_block_first * usb1;
	144	struct ufs_cg_private_info * ucpi;
	145	struct ufs_cylinder_group * ucg;
	146	struct inode * inode;
	147	unsigned cg, bit, i, j, start;
	148	struct ufs_inode_info *ufsi;
	149
abf5d15f	150	UFSD("ENTER\n");
1da177e4 LT	151
	152	/* Cannot create files in a deleted directory */
	153	if (!dir \|\| !dir->i_nlink)
	154	return ERR_PTR(-EPERM);
	155	sb = dir->i_sb;
	156	inode = new_inode(sb);
	157	if (!inode)
	158	return ERR_PTR(-ENOMEM);
	159	ufsi = UFS_I(inode);
	160	sbi = UFS_SB(sb);
	161	uspi = sbi->s_uspi;
7b4ee73e	162	usb1 = ubh_get_usb_first(uspi);
1da177e4 LT	163
	164	lock_super (sb);
	165
	166	/*
	167	* Try to place the inode in its parent directory
	168	*/
	169	i = ufs_inotocg(dir->i_ino);
	170	if (sbi->fs_cs(i).cs_nifree) {
	171	cg = i;
	172	goto cg_found;
	173	}
	174
	175	/*
	176	* Use a quadratic hash to find a group with a free inode
	177	*/
	178	for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
	179	i += j;
	180	if (i >= uspi->s_ncg)
	181	i -= uspi->s_ncg;
	182	if (sbi->fs_cs(i).cs_nifree) {
	183	cg = i;
	184	goto cg_found;
	185	}
	186	}
	187
	188	/*
	189	* That failed: try linear search for a free inode
	190	*/
	191	i = ufs_inotocg(dir->i_ino) + 1;
	192	for (j = 2; j < uspi->s_ncg; j++) {
	193	i++;
	194	if (i >= uspi->s_ncg)
	195	i = 0;
	196	if (sbi->fs_cs(i).cs_nifree) {
	197	cg = i;
	198	goto cg_found;
	199	}
	200	}
	201
	202	goto failed;
	203
	204	cg_found:
	205	ucpi = ufs_load_cylinder (sb, cg);
	206	if (!ucpi)
	207	goto failed;
9695ef16	208	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
1da177e4 LT	209	if (!ufs_cg_chkmagic(sb, ucg))
	210	ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
	211
	212	start = ucpi->c_irotor;
9695ef16	213	bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
1da177e4	214	if (!(bit < uspi->s_ipg)) {
9695ef16	215	bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
1da177e4 LT	216	if (!(bit < start)) {
	217	ufs_error (sb, "ufs_new_inode",
	218	"cylinder group %u corrupted - error in inode bitmap\n", cg);
	219	goto failed;
	220	}
	221	}
abf5d15f	222	UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
9695ef16 ED	223	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
9695ef16 ED	224	ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
1da177e4 LT	225	else {
	226	ufs_panic (sb, "ufs_new_inode", "internal error");
	227	goto failed;
	228	}
	229
	230	fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
ee3ffd6c	231	uspi->cs_total.cs_nifree--;
1da177e4 LT	232	fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
	233
	234	if (S_ISDIR(mode)) {
	235	fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
ee3ffd6c	236	uspi->cs_total.cs_ndir++;
1da177e4 LT	237	fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
	238	}
	239
9695ef16 ED	240	ubh_mark_buffer_dirty (USPI_UBH(uspi));
9695ef16 ED	241	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
1da177e4	242	if (sb->s_flags & MS_SYNCHRONOUS) {
098d5af7	243	ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
9695ef16	244	ubh_wait_on_buffer (UCPI_UBH(ucpi));
1da177e4 LT	245	}
	246	sb->s_dirt = 1;
	247
	248	inode->i_mode = mode;
	249	inode->i_uid = current->fsuid;
	250	if (dir->i_mode & S_ISGID) {
	251	inode->i_gid = dir->i_gid;
	252	if (S_ISDIR(mode))
	253	inode->i_mode \|= S_ISGID;
	254	} else
	255	inode->i_gid = current->fsgid;
	256
	257	inode->i_ino = cg * uspi->s_ipg + bit;
1da177e4 LT	258	inode->i_blocks = 0;
	259	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	260	ufsi->i_flags = UFS_I(dir)->i_flags;
	261	ufsi->i_lastfrag = 0;
	262	ufsi->i_gen = 0;
	263	ufsi->i_shadow = 0;
	264	ufsi->i_osync = 0;
	265	ufsi->i_oeftflag = 0;
dd187a26	266	ufsi->i_dir_start_lookup = 0;
1da177e4 LT	267	memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
	268
	269	insert_inode_hash(inode);
	270	mark_inode_dirty(inode);
	271
	272	unlock_super (sb);
	273
	274	if (DQUOT_ALLOC_INODE(inode)) {
	275	DQUOT_DROP(inode);
	276	inode->i_flags \|= S_NOQUOTA;
	277	inode->i_nlink = 0;
	278	iput(inode);
	279	return ERR_PTR(-EDQUOT);
	280	}
	281
abf5d15f ED	282	UFSD("allocating inode %lu\n", inode->i_ino);
abf5d15f ED	283	UFSD("EXIT\n");
1da177e4 LT	284	return inode;
	285
	286	failed:
	287	unlock_super (sb);
	288	make_bad_inode(inode);
	289	iput (inode);
abf5d15f	290	UFSD("EXIT (FAILED)\n");
1da177e4 LT	291	return ERR_PTR(-ENOSPC);
1da177e4 LT	292	}