- 根目录:
- fs
- ufs
- ialloc.c
/*
* linux/fs/ufs/ialloc.c
*
* Copyright (c) 1998
* Daniel Pirkl <daniel.pirkl@email.cz>
* Charles University, Faculty of Mathematics and Physics
*
* from
*
* linux/fs/ext2/ialloc.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)
*
* BSD ufs-inspired inode and directory allocation by
* Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*
* UFS2 write support added by
* Evgeniy Dushistov <dushistov@mail.ru>, 2007
*/
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/sched.h>
#include <linux/bitops.h>
#include <asm/byteorder.h>
#include "ufs_fs.h"
#include "ufs.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_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;
ino = inode->i_ino;
mutex_lock(&UFS_SB(sb)->s_lock);
if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
mutex_unlock(&UFS_SB(sb)->s_lock);
return;
}
cg = ufs_inotocg (ino);
bit = ufs_inotocgoff (ino);
ucpi = ufs_load_cylinder (sb, cg);
if (!ucpi) {
mutex_unlock(&UFS_SB(sb)->s_lock);
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);
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_sync_block(UCPI_UBH(ucpi));
ufs_mark_sb_dirty(sb);
mutex_unlock(&UFS_SB(sb)->s_lock);
UFSD("EXIT\n");
}
/*
* Nullify new chunk of inodes,
* BSD people also set ui_gen field of inode
* during nullification, but we not care about
* that because of linux ufs do not support NFS
*/
static void ufs2_init_inodes_chunk(struct super_block *sb,
struct ufs_cg_private_info *ucpi,
struct ufs_cylinder_group *ucg)
{
struct buffer_head *bh;
struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
sector_t beg = uspi->s_sbbase +
ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
sector_t end = beg + uspi->s_fpb;
UFSD("ENTER cgno %d\n", ucpi->c_cgx);
for (; beg < end; ++beg) {
bh = sb_getblk(sb, beg);
lock_buffer(bh);
memset(bh->b_data, 0, sb->s_blocksize);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
if (sb->s_flags & MS_SYNCHRONOUS)
sync_dirty_buffer(bh);
brelse(bh);
}
fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
if (sb->s_flags & MS_SYNCHRONOUS)
ubh_sync_block(UCPI_UBH(ucpi));
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, umode_t mode)
{
struct super_block * sb;
struct ufs_sb_info * sbi;
struct ufs_sb_private_info * uspi;
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;
int err = -ENOSPC;
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;
mutex_lock(&sbi->s_lock);
/*
* 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) {
err = -EIO;
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);
err = -EIO;
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");
err = -EIO;
goto failed;
}
if (uspi->fs_magic == UFS2_MAGIC) {
u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
if (bit + uspi->s_inopb > initediblk &&
initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
ufs2_init_inodes_chunk(sb, ucpi, ucg);
}
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_sync_block(UCPI_UBH(ucpi));
ufs_mark_sb_dirty(sb);
inode->i_ino = cg * uspi->s_ipg + bit;
inode_init_owner(inode, dir, mode);
inode->i_blocks = 0;
inode->i_generation = 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_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));
if (insert_inode_locked(inode) < 0) {
err = -EIO;
goto failed;
}
mark_inode_dirty(inode);
if (uspi->fs_magic == UFS2_MAGIC) {
struct buffer_head *bh;
struct ufs2_inode *ufs2_inode;
/*
* setup birth date, we do it here because of there is no sense
* to hold it in struct ufs_inode_info, and lose 64 bit
*/
bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
if (!bh) {
ufs_warning(sb, "ufs_read_inode",
"unable to read inode %lu\n",
inode->i_ino);
err = -EIO;
goto fail_remove_inode;
}
lock_buffer(bh);
ufs2_inode = (struct ufs2_inode *)bh->b_data;
ufs2_inode += ufs_inotofsbo(inode->i_ino);
ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
mark_buffer_dirty(bh);
unlock_buffer(bh);
if (sb->s_flags & MS_SYNCHRONOUS)
sync_dirty_buffer(bh);
brelse(bh);
}
mutex_unlock(&sbi->s_lock);
UFSD("allocating inode %lu\n", inode->i_ino);
UFSD("EXIT\n");
return inode;
fail_remove_inode:
mutex_unlock(&sbi->s_lock);
clear_nlink(inode);
unlock_new_inode(inode);
iput(inode);
UFSD("EXIT (FAILED): err %d\n", err);
return ERR_PTR(err);
failed:
mutex_unlock(&sbi->s_lock);
make_bad_inode(inode);
iput (inode);
UFSD("EXIT (FAILED): err %d\n", err);
return ERR_PTR(err);
}