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-rw-r--r--fs/ufs/truncate.c477
1 files changed, 477 insertions, 0 deletions
diff --git a/fs/ufs/truncate.c b/fs/ufs/truncate.c
new file mode 100644
index 000000000000..e312bf8bad9f
--- /dev/null
+++ b/fs/ufs/truncate.c
@@ -0,0 +1,477 @@
+/*
+ * linux/fs/ufs/truncate.c
+ *
+ * Copyright (C) 1998
+ * Daniel Pirkl <daniel.pirkl@email.cz>
+ * Charles University, Faculty of Mathematics and Physics
+ *
+ * from
+ *
+ * linux/fs/ext2/truncate.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)
+ *
+ * from
+ *
+ * linux/fs/minix/truncate.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+/*
+ * Real random numbers for secure rm added 94/02/18
+ * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/ufs_fs.h>
+#include <linux/fcntl.h>
+#include <linux/time.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <linux/blkdev.h>
+#include <linux/sched.h>
+
+#include "swab.h"
+#include "util.h"
+
+#undef UFS_TRUNCATE_DEBUG
+
+#ifdef UFS_TRUNCATE_DEBUG
+#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
+#else
+#define UFSD(x)
+#endif
+
+/*
+ * Secure deletion currently doesn't work. It interacts very badly
+ * with buffers shared with memory mappings, and for that reason
+ * can't be done in the truncate() routines. It should instead be
+ * done separately in "release()" before calling the truncate routines
+ * that will release the actual file blocks.
+ *
+ * Linus
+ */
+
+#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
+#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
+
+#define DATA_BUFFER_USED(bh) \
+ (atomic_read(&bh->b_count)>1 || buffer_locked(bh))
+
+static int ufs_trunc_direct (struct inode * inode)
+{
+ struct ufs_inode_info *ufsi = UFS_I(inode);
+ struct super_block * sb;
+ struct ufs_sb_private_info * uspi;
+ struct buffer_head * bh;
+ __fs32 * p;
+ unsigned frag1, frag2, frag3, frag4, block1, block2;
+ unsigned frag_to_free, free_count;
+ unsigned i, j, tmp;
+ int retry;
+
+ UFSD(("ENTER\n"))
+
+ sb = inode->i_sb;
+ uspi = UFS_SB(sb)->s_uspi;
+
+ frag_to_free = 0;
+ free_count = 0;
+ retry = 0;
+
+ frag1 = DIRECT_FRAGMENT;
+ frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
+ frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
+ frag3 = frag4 & ~uspi->s_fpbmask;
+ block1 = block2 = 0;
+ if (frag2 > frag3) {
+ frag2 = frag4;
+ frag3 = frag4 = 0;
+ }
+ else if (frag2 < frag3) {
+ block1 = ufs_fragstoblks (frag2);
+ block2 = ufs_fragstoblks (frag3);
+ }
+
+ UFSD(("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4))
+
+ if (frag1 >= frag2)
+ goto next1;
+
+ /*
+ * Free first free fragments
+ */
+ p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
+ tmp = fs32_to_cpu(sb, *p);
+ if (!tmp )
+ ufs_panic (sb, "ufs_trunc_direct", "internal error");
+ frag1 = ufs_fragnum (frag1);
+ frag2 = ufs_fragnum (frag2);
+ for (j = frag1; j < frag2; j++) {
+ bh = sb_find_get_block (sb, tmp + j);
+ if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
+ retry = 1;
+ brelse (bh);
+ goto next1;
+ }
+ bforget (bh);
+ }
+ inode->i_blocks -= (frag2-frag1) << uspi->s_nspfshift;
+ mark_inode_dirty(inode);
+ ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
+ frag_to_free = tmp + frag1;
+
+next1:
+ /*
+ * Free whole blocks
+ */
+ for (i = block1 ; i < block2; i++) {
+ p = ufsi->i_u1.i_data + i;
+ tmp = fs32_to_cpu(sb, *p);
+ if (!tmp)
+ continue;
+ for (j = 0; j < uspi->s_fpb; j++) {
+ bh = sb_find_get_block(sb, tmp + j);
+ if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
+ retry = 1;
+ brelse (bh);
+ goto next2;
+ }
+ bforget (bh);
+ }
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ if (free_count == 0) {
+ frag_to_free = tmp;
+ free_count = uspi->s_fpb;
+ } else if (free_count > 0 && frag_to_free == tmp - free_count)
+ free_count += uspi->s_fpb;
+ else {
+ ufs_free_blocks (inode, frag_to_free, free_count);
+ frag_to_free = tmp;
+ free_count = uspi->s_fpb;
+ }
+next2:;
+ }
+
+ if (free_count > 0)
+ ufs_free_blocks (inode, frag_to_free, free_count);
+
+ if (frag3 >= frag4)
+ goto next3;
+
+ /*
+ * Free last free fragments
+ */
+ p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
+ tmp = fs32_to_cpu(sb, *p);
+ if (!tmp )
+ ufs_panic(sb, "ufs_truncate_direct", "internal error");
+ frag4 = ufs_fragnum (frag4);
+ for (j = 0; j < frag4; j++) {
+ bh = sb_find_get_block (sb, tmp + j);
+ if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
+ retry = 1;
+ brelse (bh);
+ goto next1;
+ }
+ bforget (bh);
+ }
+ *p = 0;
+ inode->i_blocks -= frag4 << uspi->s_nspfshift;
+ mark_inode_dirty(inode);
+ ufs_free_fragments (inode, tmp, frag4);
+ next3:
+
+ UFSD(("EXIT\n"))
+ return retry;
+}
+
+
+static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
+{
+ struct super_block * sb;
+ struct ufs_sb_private_info * uspi;
+ struct ufs_buffer_head * ind_ubh;
+ struct buffer_head * bh;
+ __fs32 * ind;
+ unsigned indirect_block, i, j, tmp;
+ unsigned frag_to_free, free_count;
+ int retry;
+
+ UFSD(("ENTER\n"))
+
+ sb = inode->i_sb;
+ uspi = UFS_SB(sb)->s_uspi;
+
+ frag_to_free = 0;
+ free_count = 0;
+ retry = 0;
+
+ tmp = fs32_to_cpu(sb, *p);
+ if (!tmp)
+ return 0;
+ ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
+ if (tmp != fs32_to_cpu(sb, *p)) {
+ ubh_brelse (ind_ubh);
+ return 1;
+ }
+ if (!ind_ubh) {
+ *p = 0;
+ return 0;
+ }
+
+ indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
+ for (i = indirect_block; i < uspi->s_apb; i++) {
+ ind = ubh_get_addr32 (ind_ubh, i);
+ tmp = fs32_to_cpu(sb, *ind);
+ if (!tmp)
+ continue;
+ for (j = 0; j < uspi->s_fpb; j++) {
+ bh = sb_find_get_block(sb, tmp + j);
+ if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *ind)) {
+ retry = 1;
+ brelse (bh);
+ goto next;
+ }
+ bforget (bh);
+ }
+ *ind = 0;
+ ubh_mark_buffer_dirty(ind_ubh);
+ if (free_count == 0) {
+ frag_to_free = tmp;
+ free_count = uspi->s_fpb;
+ } else if (free_count > 0 && frag_to_free == tmp - free_count)
+ free_count += uspi->s_fpb;
+ else {
+ ufs_free_blocks (inode, frag_to_free, free_count);
+ frag_to_free = tmp;
+ free_count = uspi->s_fpb;
+ }
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+next:;
+ }
+
+ if (free_count > 0) {
+ ufs_free_blocks (inode, frag_to_free, free_count);
+ }
+ for (i = 0; i < uspi->s_apb; i++)
+ if (*ubh_get_addr32(ind_ubh,i))
+ break;
+ if (i >= uspi->s_apb) {
+ if (ubh_max_bcount(ind_ubh) != 1) {
+ retry = 1;
+ }
+ else {
+ tmp = fs32_to_cpu(sb, *p);
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ ufs_free_blocks (inode, tmp, uspi->s_fpb);
+ ubh_bforget(ind_ubh);
+ ind_ubh = NULL;
+ }
+ }
+ if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
+ ubh_wait_on_buffer (ind_ubh);
+ ubh_ll_rw_block (WRITE, 1, &ind_ubh);
+ ubh_wait_on_buffer (ind_ubh);
+ }
+ ubh_brelse (ind_ubh);
+
+ UFSD(("EXIT\n"))
+
+ return retry;
+}
+
+static int ufs_trunc_dindirect (struct inode *inode, unsigned offset, __fs32 *p)
+{
+ struct super_block * sb;
+ struct ufs_sb_private_info * uspi;
+ struct ufs_buffer_head * dind_bh;
+ unsigned i, tmp, dindirect_block;
+ __fs32 * dind;
+ int retry = 0;
+
+ UFSD(("ENTER\n"))
+
+ sb = inode->i_sb;
+ uspi = UFS_SB(sb)->s_uspi;
+
+ dindirect_block = (DIRECT_BLOCK > offset)
+ ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
+ retry = 0;
+
+ tmp = fs32_to_cpu(sb, *p);
+ if (!tmp)
+ return 0;
+ dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
+ if (tmp != fs32_to_cpu(sb, *p)) {
+ ubh_brelse (dind_bh);
+ return 1;
+ }
+ if (!dind_bh) {
+ *p = 0;
+ return 0;
+ }
+
+ for (i = dindirect_block ; i < uspi->s_apb ; i++) {
+ dind = ubh_get_addr32 (dind_bh, i);
+ tmp = fs32_to_cpu(sb, *dind);
+ if (!tmp)
+ continue;
+ retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
+ ubh_mark_buffer_dirty(dind_bh);
+ }
+
+ for (i = 0; i < uspi->s_apb; i++)
+ if (*ubh_get_addr32 (dind_bh, i))
+ break;
+ if (i >= uspi->s_apb) {
+ if (ubh_max_bcount(dind_bh) != 1)
+ retry = 1;
+ else {
+ tmp = fs32_to_cpu(sb, *p);
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ ufs_free_blocks (inode, tmp, uspi->s_fpb);
+ ubh_bforget(dind_bh);
+ dind_bh = NULL;
+ }
+ }
+ if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
+ ubh_wait_on_buffer (dind_bh);
+ ubh_ll_rw_block (WRITE, 1, &dind_bh);
+ ubh_wait_on_buffer (dind_bh);
+ }
+ ubh_brelse (dind_bh);
+
+ UFSD(("EXIT\n"))
+
+ return retry;
+}
+
+static int ufs_trunc_tindirect (struct inode * inode)
+{
+ struct ufs_inode_info *ufsi = UFS_I(inode);
+ struct super_block * sb;
+ struct ufs_sb_private_info * uspi;
+ struct ufs_buffer_head * tind_bh;
+ unsigned tindirect_block, tmp, i;
+ __fs32 * tind, * p;
+ int retry;
+
+ UFSD(("ENTER\n"))
+
+ sb = inode->i_sb;
+ uspi = UFS_SB(sb)->s_uspi;
+ retry = 0;
+
+ tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
+ ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
+ p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
+ if (!(tmp = fs32_to_cpu(sb, *p)))
+ return 0;
+ tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
+ if (tmp != fs32_to_cpu(sb, *p)) {
+ ubh_brelse (tind_bh);
+ return 1;
+ }
+ if (!tind_bh) {
+ *p = 0;
+ return 0;
+ }
+
+ for (i = tindirect_block ; i < uspi->s_apb ; i++) {
+ tind = ubh_get_addr32 (tind_bh, i);
+ retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
+ uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
+ ubh_mark_buffer_dirty(tind_bh);
+ }
+ for (i = 0; i < uspi->s_apb; i++)
+ if (*ubh_get_addr32 (tind_bh, i))
+ break;
+ if (i >= uspi->s_apb) {
+ if (ubh_max_bcount(tind_bh) != 1)
+ retry = 1;
+ else {
+ tmp = fs32_to_cpu(sb, *p);
+ *p = 0;
+ inode->i_blocks -= uspi->s_nspb;
+ mark_inode_dirty(inode);
+ ufs_free_blocks (inode, tmp, uspi->s_fpb);
+ ubh_bforget(tind_bh);
+ tind_bh = NULL;
+ }
+ }
+ if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
+ ubh_wait_on_buffer (tind_bh);
+ ubh_ll_rw_block (WRITE, 1, &tind_bh);
+ ubh_wait_on_buffer (tind_bh);
+ }
+ ubh_brelse (tind_bh);
+
+ UFSD(("EXIT\n"))
+ return retry;
+}
+
+void ufs_truncate (struct inode * inode)
+{
+ struct ufs_inode_info *ufsi = UFS_I(inode);
+ struct super_block * sb;
+ struct ufs_sb_private_info * uspi;
+ struct buffer_head * bh;
+ unsigned offset;
+ int err, retry;
+
+ UFSD(("ENTER\n"))
+ sb = inode->i_sb;
+ uspi = UFS_SB(sb)->s_uspi;
+
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+ lock_kernel();
+ while (1) {
+ retry = ufs_trunc_direct(inode);
+ retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
+ (__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
+ retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
+ (__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
+ retry |= ufs_trunc_tindirect (inode);
+ if (!retry)
+ break;
+ if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
+ ufs_sync_inode (inode);
+ blk_run_address_space(inode->i_mapping);
+ yield();
+ }
+ offset = inode->i_size & uspi->s_fshift;
+ if (offset) {
+ bh = ufs_bread (inode, inode->i_size >> uspi->s_fshift, 0, &err);
+ if (bh) {
+ memset (bh->b_data + offset, 0, uspi->s_fsize - offset);
+ mark_buffer_dirty (bh);
+ brelse (bh);
+ }
+ }
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+ ufsi->i_lastfrag = DIRECT_FRAGMENT;
+ unlock_kernel();
+ mark_inode_dirty(inode);
+ UFSD(("EXIT\n"))
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.