Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Linus Torvalds | 1709 | 48.52% | 5 | 4.39% |
Linus Torvalds (pre-git) | 479 | 13.60% | 35 | 30.70% |
Andrew Morton | 330 | 9.37% | 8 | 7.02% |
Matthew Wilcox | 237 | 6.73% | 10 | 8.77% |
Al Viro | 179 | 5.08% | 14 | 12.28% |
Jan Kara | 149 | 4.23% | 5 | 4.39% |
Eric Sandeen | 118 | 3.35% | 3 | 2.63% |
Nicholas Piggin | 85 | 2.41% | 2 | 1.75% |
Christoph Hellwig | 41 | 1.16% | 5 | 4.39% |
Jeff Layton | 30 | 0.85% | 3 | 2.63% |
Jan Blunck | 28 | 0.80% | 1 | 0.88% |
zhangyi (F) | 28 | 0.80% | 2 | 1.75% |
Ira Weiny | 27 | 0.77% | 2 | 1.75% |
Phillip Potter | 15 | 0.43% | 1 | 0.88% |
David Howells | 13 | 0.37% | 2 | 1.75% |
Kirill A. Shutemov | 10 | 0.28% | 2 | 1.75% |
Deepa Dinamani | 9 | 0.26% | 1 | 0.88% |
Harvey Harrison | 7 | 0.20% | 1 | 0.88% |
Javier Pello | 5 | 0.14% | 1 | 0.88% |
Julia Lawall | 4 | 0.11% | 1 | 0.88% |
mlafon@arkoon.net | 4 | 0.11% | 1 | 0.88% |
Brian Gerst | 3 | 0.09% | 1 | 0.88% |
Akinobu Mita | 3 | 0.09% | 1 | 0.88% |
Eric Sesterhenn / Snakebyte | 2 | 0.06% | 1 | 0.88% |
Goffredo Baroncelli | 2 | 0.06% | 1 | 0.88% |
Andi Kleen | 1 | 0.03% | 1 | 0.88% |
Arjan van de Ven | 1 | 0.03% | 1 | 0.88% |
Ye Bin | 1 | 0.03% | 1 | 0.88% |
Greg Kroah-Hartman | 1 | 0.03% | 1 | 0.88% |
Fabio M. De Francesco | 1 | 0.03% | 1 | 0.88% |
Total | 3522 | 114 |
// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/ext2/dir.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/dir.c * * Copyright (C) 1991, 1992 Linus Torvalds * * ext2 directory handling functions * * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 * * All code that works with directory layout had been switched to pagecache * and moved here. AV */ #include "ext2.h" #include <linux/buffer_head.h> #include <linux/pagemap.h> #include <linux/swap.h> #include <linux/iversion.h> typedef struct ext2_dir_entry_2 ext2_dirent; /* * Tests against MAX_REC_LEN etc were put in place for 64k block * sizes; if that is not possible on this arch, we can skip * those tests and speed things up. */ static inline unsigned ext2_rec_len_from_disk(__le16 dlen) { unsigned len = le16_to_cpu(dlen); #if (PAGE_SIZE >= 65536) if (len == EXT2_MAX_REC_LEN) return 1 << 16; #endif return len; } static inline __le16 ext2_rec_len_to_disk(unsigned len) { #if (PAGE_SIZE >= 65536) if (len == (1 << 16)) return cpu_to_le16(EXT2_MAX_REC_LEN); else BUG_ON(len > (1 << 16)); #endif return cpu_to_le16(len); } /* * ext2 uses block-sized chunks. Arguably, sector-sized ones would be * more robust, but we have what we have */ static inline unsigned ext2_chunk_size(struct inode *inode) { return inode->i_sb->s_blocksize; } /* * Return the offset into page `page_nr' of the last valid * byte in that page, plus one. */ static unsigned ext2_last_byte(struct inode *inode, unsigned long page_nr) { unsigned last_byte = inode->i_size; last_byte -= page_nr << PAGE_SHIFT; if (last_byte > PAGE_SIZE) last_byte = PAGE_SIZE; return last_byte; } static void ext2_commit_chunk(struct folio *folio, loff_t pos, unsigned len) { struct address_space *mapping = folio->mapping; struct inode *dir = mapping->host; inode_inc_iversion(dir); block_write_end(NULL, mapping, pos, len, len, &folio->page, NULL); if (pos+len > dir->i_size) { i_size_write(dir, pos+len); mark_inode_dirty(dir); } folio_unlock(folio); } static bool ext2_check_folio(struct folio *folio, int quiet, char *kaddr) { struct inode *dir = folio->mapping->host; struct super_block *sb = dir->i_sb; unsigned chunk_size = ext2_chunk_size(dir); u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); unsigned offs, rec_len; unsigned limit = folio_size(folio); ext2_dirent *p; char *error; if (dir->i_size < folio_pos(folio) + limit) { limit = offset_in_folio(folio, dir->i_size); if (limit & (chunk_size - 1)) goto Ebadsize; if (!limit) goto out; } for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) { p = (ext2_dirent *)(kaddr + offs); rec_len = ext2_rec_len_from_disk(p->rec_len); if (unlikely(rec_len < EXT2_DIR_REC_LEN(1))) goto Eshort; if (unlikely(rec_len & 3)) goto Ealign; if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len))) goto Enamelen; if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))) goto Espan; if (unlikely(le32_to_cpu(p->inode) > max_inumber)) goto Einumber; } if (offs != limit) goto Eend; out: folio_set_checked(folio); return true; /* Too bad, we had an error */ Ebadsize: if (!quiet) ext2_error(sb, __func__, "size of directory #%lu is not a multiple " "of chunk size", dir->i_ino); goto fail; Eshort: error = "rec_len is smaller than minimal"; goto bad_entry; Ealign: error = "unaligned directory entry"; goto bad_entry; Enamelen: error = "rec_len is too small for name_len"; goto bad_entry; Espan: error = "directory entry across blocks"; goto bad_entry; Einumber: error = "inode out of bounds"; bad_entry: if (!quiet) ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - " "offset=%llu, inode=%lu, rec_len=%d, name_len=%d", dir->i_ino, error, folio_pos(folio) + offs, (unsigned long) le32_to_cpu(p->inode), rec_len, p->name_len); goto fail; Eend: if (!quiet) { p = (ext2_dirent *)(kaddr + offs); ext2_error(sb, "ext2_check_folio", "entry in directory #%lu spans the page boundary" "offset=%llu, inode=%lu", dir->i_ino, folio_pos(folio) + offs, (unsigned long) le32_to_cpu(p->inode)); } fail: folio_set_error(folio); return false; } /* * Calls to ext2_get_folio()/folio_release_kmap() must be nested according * to the rules documented in kmap_local_folio()/kunmap_local(). * * NOTE: ext2_find_entry() and ext2_dotdot() act as a call * to folio_release_kmap() and should be treated as a call to * folio_release_kmap() for nesting purposes. */ static void *ext2_get_folio(struct inode *dir, unsigned long n, int quiet, struct folio **foliop) { struct address_space *mapping = dir->i_mapping; struct folio *folio = read_mapping_folio(mapping, n, NULL); void *kaddr; if (IS_ERR(folio)) return ERR_CAST(folio); kaddr = kmap_local_folio(folio, 0); if (unlikely(!folio_test_checked(folio))) { if (!ext2_check_folio(folio, quiet, kaddr)) goto fail; } *foliop = folio; return kaddr; fail: folio_release_kmap(folio, kaddr); return ERR_PTR(-EIO); } /* * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure. * * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller. */ static inline int ext2_match (int len, const char * const name, struct ext2_dir_entry_2 * de) { if (len != de->name_len) return 0; if (!de->inode) return 0; return !memcmp(name, de->name, len); } /* * p is at least 6 bytes before the end of page */ static inline ext2_dirent *ext2_next_entry(ext2_dirent *p) { return (ext2_dirent *)((char *)p + ext2_rec_len_from_disk(p->rec_len)); } static inline unsigned ext2_validate_entry(char *base, unsigned offset, unsigned mask) { ext2_dirent *de = (ext2_dirent*)(base + offset); ext2_dirent *p = (ext2_dirent*)(base + (offset&mask)); while ((char*)p < (char*)de) { if (p->rec_len == 0) break; p = ext2_next_entry(p); } return offset_in_page(p); } static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) { if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) de->file_type = fs_umode_to_ftype(inode->i_mode); else de->file_type = 0; } static int ext2_readdir(struct file *file, struct dir_context *ctx) { loff_t pos = ctx->pos; struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; unsigned int offset = pos & ~PAGE_MASK; unsigned long n = pos >> PAGE_SHIFT; unsigned long npages = dir_pages(inode); unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); bool need_revalidate = !inode_eq_iversion(inode, file->f_version); bool has_filetype; if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) return 0; has_filetype = EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE); for ( ; n < npages; n++, offset = 0) { ext2_dirent *de; struct folio *folio; char *kaddr = ext2_get_folio(inode, n, 0, &folio); char *limit; if (IS_ERR(kaddr)) { ext2_error(sb, __func__, "bad page in #%lu", inode->i_ino); ctx->pos += PAGE_SIZE - offset; return PTR_ERR(kaddr); } if (unlikely(need_revalidate)) { if (offset) { offset = ext2_validate_entry(kaddr, offset, chunk_mask); ctx->pos = (n<<PAGE_SHIFT) + offset; } file->f_version = inode_query_iversion(inode); need_revalidate = false; } de = (ext2_dirent *)(kaddr+offset); limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1); for ( ;(char*)de <= limit; de = ext2_next_entry(de)) { if (de->rec_len == 0) { ext2_error(sb, __func__, "zero-length directory entry"); folio_release_kmap(folio, de); return -EIO; } if (de->inode) { unsigned char d_type = DT_UNKNOWN; if (has_filetype) d_type = fs_ftype_to_dtype(de->file_type); if (!dir_emit(ctx, de->name, de->name_len, le32_to_cpu(de->inode), d_type)) { folio_release_kmap(folio, de); return 0; } } ctx->pos += ext2_rec_len_from_disk(de->rec_len); } folio_release_kmap(folio, kaddr); } return 0; } /* * ext2_find_entry() * * finds an entry in the specified directory with the wanted name. It * returns the page in which the entry was found (as a parameter - res_page), * and the entry itself. Page is returned mapped and unlocked. * Entry is guaranteed to be valid. * * On Success folio_release_kmap() should be called on *foliop. * * NOTE: Calls to ext2_get_folio()/folio_release_kmap() must be nested * according to the rules documented in kmap_local_folio()/kunmap_local(). * * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_folio() * and should be treated as a call to ext2_get_folio() for nesting * purposes. */ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir, const struct qstr *child, struct folio **foliop) { const char *name = child->name; int namelen = child->len; unsigned reclen = EXT2_DIR_REC_LEN(namelen); unsigned long start, n; unsigned long npages = dir_pages(dir); struct ext2_inode_info *ei = EXT2_I(dir); ext2_dirent * de; if (npages == 0) goto out; start = ei->i_dir_start_lookup; if (start >= npages) start = 0; n = start; do { char *kaddr = ext2_get_folio(dir, n, 0, foliop); if (IS_ERR(kaddr)) return ERR_CAST(kaddr); de = (ext2_dirent *) kaddr; kaddr += ext2_last_byte(dir, n) - reclen; while ((char *) de <= kaddr) { if (de->rec_len == 0) { ext2_error(dir->i_sb, __func__, "zero-length directory entry"); folio_release_kmap(*foliop, de); goto out; } if (ext2_match(namelen, name, de)) goto found; de = ext2_next_entry(de); } folio_release_kmap(*foliop, kaddr); if (++n >= npages) n = 0; /* next folio is past the blocks we've got */ if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) { ext2_error(dir->i_sb, __func__, "dir %lu size %lld exceeds block count %llu", dir->i_ino, dir->i_size, (unsigned long long)dir->i_blocks); goto out; } } while (n != start); out: return ERR_PTR(-ENOENT); found: ei->i_dir_start_lookup = n; return de; } /* * Return the '..' directory entry and the page in which the entry was found * (as a parameter - p). * * On Success folio_release_kmap() should be called on *foliop. * * NOTE: Calls to ext2_get_folio()/folio_release_kmap() must be nested * according to the rules documented in kmap_local_folio()/kunmap_local(). * * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_folio() * and should be treated as a call to ext2_get_folio() for nesting * purposes. */ struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct folio **foliop) { ext2_dirent *de = ext2_get_folio(dir, 0, 0, foliop); if (!IS_ERR(de)) return ext2_next_entry(de); return NULL; } int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino) { struct ext2_dir_entry_2 *de; struct folio *folio; de = ext2_find_entry(dir, child, &folio); if (IS_ERR(de)) return PTR_ERR(de); *ino = le32_to_cpu(de->inode); folio_release_kmap(folio, de); return 0; } static int ext2_prepare_chunk(struct folio *folio, loff_t pos, unsigned len) { return __block_write_begin(&folio->page, pos, len, ext2_get_block); } static int ext2_handle_dirsync(struct inode *dir) { int err; err = filemap_write_and_wait(dir->i_mapping); if (!err) err = sync_inode_metadata(dir, 1); return err; } int ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, struct folio *folio, struct inode *inode, bool update_times) { loff_t pos = folio_pos(folio) + offset_in_folio(folio, de); unsigned len = ext2_rec_len_from_disk(de->rec_len); int err; folio_lock(folio); err = ext2_prepare_chunk(folio, pos, len); if (err) { folio_unlock(folio); return err; } de->inode = cpu_to_le32(inode->i_ino); ext2_set_de_type(de, inode); ext2_commit_chunk(folio, pos, len); if (update_times) inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; mark_inode_dirty(dir); return ext2_handle_dirsync(dir); } /* * Parent is locked. */ int ext2_add_link (struct dentry *dentry, struct inode *inode) { struct inode *dir = d_inode(dentry->d_parent); const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; unsigned chunk_size = ext2_chunk_size(dir); unsigned reclen = EXT2_DIR_REC_LEN(namelen); unsigned short rec_len, name_len; struct folio *folio = NULL; ext2_dirent * de; unsigned long npages = dir_pages(dir); unsigned long n; loff_t pos; int err; /* * We take care of directory expansion in the same loop. * This code plays outside i_size, so it locks the folio * to protect that region. */ for (n = 0; n <= npages; n++) { char *kaddr = ext2_get_folio(dir, n, 0, &folio); char *dir_end; if (IS_ERR(kaddr)) return PTR_ERR(kaddr); folio_lock(folio); dir_end = kaddr + ext2_last_byte(dir, n); de = (ext2_dirent *)kaddr; kaddr += folio_size(folio) - reclen; while ((char *)de <= kaddr) { if ((char *)de == dir_end) { /* We hit i_size */ name_len = 0; rec_len = chunk_size; de->rec_len = ext2_rec_len_to_disk(chunk_size); de->inode = 0; goto got_it; } if (de->rec_len == 0) { ext2_error(dir->i_sb, __func__, "zero-length directory entry"); err = -EIO; goto out_unlock; } err = -EEXIST; if (ext2_match (namelen, name, de)) goto out_unlock; name_len = EXT2_DIR_REC_LEN(de->name_len); rec_len = ext2_rec_len_from_disk(de->rec_len); if (!de->inode && rec_len >= reclen) goto got_it; if (rec_len >= name_len + reclen) goto got_it; de = (ext2_dirent *) ((char *) de + rec_len); } folio_unlock(folio); folio_release_kmap(folio, kaddr); } BUG(); return -EINVAL; got_it: pos = folio_pos(folio) + offset_in_folio(folio, de); err = ext2_prepare_chunk(folio, pos, rec_len); if (err) goto out_unlock; if (de->inode) { ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len); de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len); de->rec_len = ext2_rec_len_to_disk(name_len); de = de1; } de->name_len = namelen; memcpy(de->name, name, namelen); de->inode = cpu_to_le32(inode->i_ino); ext2_set_de_type (de, inode); ext2_commit_chunk(folio, pos, rec_len); inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL; mark_inode_dirty(dir); err = ext2_handle_dirsync(dir); /* OFFSET_CACHE */ out_put: folio_release_kmap(folio, de); return err; out_unlock: folio_unlock(folio); goto out_put; } /* * ext2_delete_entry deletes a directory entry by merging it with the * previous entry. Page is up-to-date. */ int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct folio *folio) { struct inode *inode = folio->mapping->host; size_t from, to; char *kaddr; loff_t pos; ext2_dirent *de, *pde = NULL; int err; from = offset_in_folio(folio, dir); to = from + ext2_rec_len_from_disk(dir->rec_len); kaddr = (char *)dir - from; from &= ~(ext2_chunk_size(inode)-1); de = (ext2_dirent *)(kaddr + from); while ((char*)de < (char*)dir) { if (de->rec_len == 0) { ext2_error(inode->i_sb, __func__, "zero-length directory entry"); return -EIO; } pde = de; de = ext2_next_entry(de); } if (pde) from = offset_in_folio(folio, pde); pos = folio_pos(folio) + from; folio_lock(folio); err = ext2_prepare_chunk(folio, pos, to - from); if (err) { folio_unlock(folio); return err; } if (pde) pde->rec_len = ext2_rec_len_to_disk(to - from); dir->inode = 0; ext2_commit_chunk(folio, pos, to - from); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL; mark_inode_dirty(inode); return ext2_handle_dirsync(inode); } /* * Set the first fragment of directory. */ int ext2_make_empty(struct inode *inode, struct inode *parent) { struct folio *folio = filemap_grab_folio(inode->i_mapping, 0); unsigned chunk_size = ext2_chunk_size(inode); struct ext2_dir_entry_2 * de; int err; void *kaddr; if (IS_ERR(folio)) return PTR_ERR(folio); err = ext2_prepare_chunk(folio, 0, chunk_size); if (err) { folio_unlock(folio); goto fail; } kaddr = kmap_local_folio(folio, 0); memset(kaddr, 0, chunk_size); de = (struct ext2_dir_entry_2 *)kaddr; de->name_len = 1; de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1)); memcpy (de->name, ".\0\0", 4); de->inode = cpu_to_le32(inode->i_ino); ext2_set_de_type (de, inode); de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1)); de->name_len = 2; de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1)); de->inode = cpu_to_le32(parent->i_ino); memcpy (de->name, "..\0", 4); ext2_set_de_type (de, inode); kunmap_local(kaddr); ext2_commit_chunk(folio, 0, chunk_size); err = ext2_handle_dirsync(inode); fail: folio_put(folio); return err; } /* * routine to check that the specified directory is empty (for rmdir) */ int ext2_empty_dir(struct inode *inode) { struct folio *folio; char *kaddr; unsigned long i, npages = dir_pages(inode); for (i = 0; i < npages; i++) { ext2_dirent *de; kaddr = ext2_get_folio(inode, i, 0, &folio); if (IS_ERR(kaddr)) return 0; de = (ext2_dirent *)kaddr; kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1); while ((char *)de <= kaddr) { if (de->rec_len == 0) { ext2_error(inode->i_sb, __func__, "zero-length directory entry"); printk("kaddr=%p, de=%p\n", kaddr, de); goto not_empty; } if (de->inode != 0) { /* check for . and .. */ if (de->name[0] != '.') goto not_empty; if (de->name_len > 2) goto not_empty; if (de->name_len < 2) { if (de->inode != cpu_to_le32(inode->i_ino)) goto not_empty; } else if (de->name[1] != '.') goto not_empty; } de = ext2_next_entry(de); } folio_release_kmap(folio, kaddr); } return 1; not_empty: folio_release_kmap(folio, kaddr); return 0; } const struct file_operations ext2_dir_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, .iterate_shared = ext2_readdir, .unlocked_ioctl = ext2_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = ext2_compat_ioctl, #endif .fsync = ext2_fsync, };
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