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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/ufs/ialloc.c
Initial import
Diffstat (limited to 'fs/ufs/ialloc.c')
-rw-r--r--fs/ufs/ialloc.c353
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diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
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+/*
+ * 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);
+}