/* * 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> */ /* * Modified to avoid infinite loop on 2006 by * Evgeniy Dushistov <dushistov@mail.ru> */ #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) 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; __fs32 * p; unsigned frag1, frag2, frag3, frag4, block1, block2; unsigned frag_to_free, free_count; unsigned i, 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); 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; *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; } } 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); *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; __fs32 * ind; unsigned indirect_block, i, 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; *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); } 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_ll_rw_block (SWRITE, 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_ll_rw_block (SWRITE, 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_ll_rw_block (SWRITE, 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; int 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; block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block); 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(); } inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; ufsi->i_lastfrag = DIRECT_FRAGMENT; unlock_kernel(); mark_inode_dirty(inode); UFSD(("EXIT\n")) }