summaryrefslogtreecommitdiffstats
path: root/fs/ufs/dir.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ufs/dir.c')
-rw-r--r--fs/ufs/dir.c655
1 files changed, 655 insertions, 0 deletions
diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
new file mode 100644
index 0000000000..fd57f03b6c
--- /dev/null
+++ b/fs/ufs/dir.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ufs/ufs_dir.c
+ *
+ * Copyright (C) 1996
+ * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
+ * Laboratory for Computer Science Research Computing Facility
+ * Rutgers, The State University of New Jersey
+ *
+ * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
+ *
+ * 4.4BSD (FreeBSD) support added on February 1st 1998 by
+ * Niels Kristian Bech Jensen <nkbj@image.dk> partially based
+ * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
+ *
+ * Migration to usage of "page cache" on May 2006 by
+ * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/swap.h>
+#include <linux/iversion.h>
+
+#include "ufs_fs.h"
+#include "ufs.h"
+#include "swab.h"
+#include "util.h"
+
+/*
+ * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
+ *
+ * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
+ */
+static inline int ufs_match(struct super_block *sb, int len,
+ const unsigned char *name, struct ufs_dir_entry *de)
+{
+ if (len != ufs_get_de_namlen(sb, de))
+ return 0;
+ if (!de->d_ino)
+ return 0;
+ return !memcmp(name, de->d_name, len);
+}
+
+static void ufs_commit_chunk(struct page *page, loff_t pos, unsigned len)
+{
+ struct address_space *mapping = page->mapping;
+ struct inode *dir = mapping->host;
+
+ inode_inc_iversion(dir);
+ block_write_end(NULL, mapping, pos, len, len, page, NULL);
+ if (pos+len > dir->i_size) {
+ i_size_write(dir, pos+len);
+ mark_inode_dirty(dir);
+ }
+ unlock_page(page);
+}
+
+static int ufs_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;
+}
+
+static inline void ufs_put_page(struct page *page)
+{
+ kunmap(page);
+ put_page(page);
+}
+
+ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
+{
+ ino_t res = 0;
+ struct ufs_dir_entry *de;
+ struct page *page;
+
+ de = ufs_find_entry(dir, qstr, &page);
+ if (de) {
+ res = fs32_to_cpu(dir->i_sb, de->d_ino);
+ ufs_put_page(page);
+ }
+ return res;
+}
+
+
+/* Releases the page */
+void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
+ struct page *page, struct inode *inode,
+ bool update_times)
+{
+ loff_t pos = page_offset(page) +
+ (char *) de - (char *) page_address(page);
+ unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
+ int err;
+
+ lock_page(page);
+ err = ufs_prepare_chunk(page, pos, len);
+ BUG_ON(err);
+
+ de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
+ ufs_set_de_type(dir->i_sb, de, inode->i_mode);
+
+ ufs_commit_chunk(page, pos, len);
+ ufs_put_page(page);
+ if (update_times)
+ dir->i_mtime = inode_set_ctime_current(dir);
+ mark_inode_dirty(dir);
+ ufs_handle_dirsync(dir);
+}
+
+
+static bool ufs_check_page(struct page *page)
+{
+ struct inode *dir = page->mapping->host;
+ struct super_block *sb = dir->i_sb;
+ char *kaddr = page_address(page);
+ unsigned offs, rec_len;
+ unsigned limit = PAGE_SIZE;
+ const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
+ struct ufs_dir_entry *p;
+ char *error;
+
+ if ((dir->i_size >> PAGE_SHIFT) == page->index) {
+ limit = dir->i_size & ~PAGE_MASK;
+ if (limit & chunk_mask)
+ goto Ebadsize;
+ if (!limit)
+ goto out;
+ }
+ for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
+ p = (struct ufs_dir_entry *)(kaddr + offs);
+ rec_len = fs16_to_cpu(sb, p->d_reclen);
+
+ if (rec_len < UFS_DIR_REC_LEN(1))
+ goto Eshort;
+ if (rec_len & 3)
+ goto Ealign;
+ if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
+ goto Enamelen;
+ if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
+ goto Espan;
+ if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
+ UFS_SB(sb)->s_uspi->s_ncg))
+ goto Einumber;
+ }
+ if (offs != limit)
+ goto Eend;
+out:
+ SetPageChecked(page);
+ return true;
+
+ /* Too bad, we had an error */
+
+Ebadsize:
+ ufs_error(sb, "ufs_check_page",
+ "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:
+ ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
+ "offset=%lu, rec_len=%d, name_len=%d",
+ dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs,
+ rec_len, ufs_get_de_namlen(sb, p));
+ goto fail;
+Eend:
+ p = (struct ufs_dir_entry *)(kaddr + offs);
+ ufs_error(sb, __func__,
+ "entry in directory #%lu spans the page boundary"
+ "offset=%lu",
+ dir->i_ino, (page->index<<PAGE_SHIFT)+offs);
+fail:
+ SetPageError(page);
+ return false;
+}
+
+static struct page *ufs_get_page(struct inode *dir, unsigned long n)
+{
+ struct address_space *mapping = dir->i_mapping;
+ struct page *page = read_mapping_page(mapping, n, NULL);
+ if (!IS_ERR(page)) {
+ kmap(page);
+ if (unlikely(!PageChecked(page))) {
+ if (!ufs_check_page(page))
+ goto fail;
+ }
+ }
+ return page;
+
+fail:
+ ufs_put_page(page);
+ return ERR_PTR(-EIO);
+}
+
+/*
+ * Return the offset into page `page_nr' of the last valid
+ * byte in that page, plus one.
+ */
+static unsigned
+ufs_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 inline struct ufs_dir_entry *
+ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
+{
+ return (struct ufs_dir_entry *)((char *)p +
+ fs16_to_cpu(sb, p->d_reclen));
+}
+
+struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
+{
+ struct page *page = ufs_get_page(dir, 0);
+ struct ufs_dir_entry *de = NULL;
+
+ if (!IS_ERR(page)) {
+ de = ufs_next_entry(dir->i_sb,
+ (struct ufs_dir_entry *)page_address(page));
+ *p = page;
+ }
+ return de;
+}
+
+/*
+ * ufs_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the page in which the entry was found, and the entry itself
+ * (as a parameter - res_dir). Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
+ struct page **res_page)
+{
+ struct super_block *sb = dir->i_sb;
+ const unsigned char *name = qstr->name;
+ int namelen = qstr->len;
+ unsigned reclen = UFS_DIR_REC_LEN(namelen);
+ unsigned long start, n;
+ unsigned long npages = dir_pages(dir);
+ struct page *page = NULL;
+ struct ufs_inode_info *ui = UFS_I(dir);
+ struct ufs_dir_entry *de;
+
+ UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
+
+ if (npages == 0 || namelen > UFS_MAXNAMLEN)
+ goto out;
+
+ /* OFFSET_CACHE */
+ *res_page = NULL;
+
+ start = ui->i_dir_start_lookup;
+
+ if (start >= npages)
+ start = 0;
+ n = start;
+ do {
+ char *kaddr;
+ page = ufs_get_page(dir, n);
+ if (!IS_ERR(page)) {
+ kaddr = page_address(page);
+ de = (struct ufs_dir_entry *) kaddr;
+ kaddr += ufs_last_byte(dir, n) - reclen;
+ while ((char *) de <= kaddr) {
+ if (ufs_match(sb, namelen, name, de))
+ goto found;
+ de = ufs_next_entry(sb, de);
+ }
+ ufs_put_page(page);
+ }
+ if (++n >= npages)
+ n = 0;
+ } while (n != start);
+out:
+ return NULL;
+
+found:
+ *res_page = page;
+ ui->i_dir_start_lookup = n;
+ return de;
+}
+
+/*
+ * Parent is locked.
+ */
+int ufs_add_link(struct dentry *dentry, struct inode *inode)
+{
+ struct inode *dir = d_inode(dentry->d_parent);
+ const unsigned char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct super_block *sb = dir->i_sb;
+ unsigned reclen = UFS_DIR_REC_LEN(namelen);
+ const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
+ unsigned short rec_len, name_len;
+ struct page *page = NULL;
+ struct ufs_dir_entry *de;
+ unsigned long npages = dir_pages(dir);
+ unsigned long n;
+ char *kaddr;
+ loff_t pos;
+ int err;
+
+ UFSD("ENTER, name %s, namelen %u\n", name, namelen);
+
+ /*
+ * We take care of directory expansion in the same loop.
+ * This code plays outside i_size, so it locks the page
+ * to protect that region.
+ */
+ for (n = 0; n <= npages; n++) {
+ char *dir_end;
+
+ page = ufs_get_page(dir, n);
+ err = PTR_ERR(page);
+ if (IS_ERR(page))
+ goto out;
+ lock_page(page);
+ kaddr = page_address(page);
+ dir_end = kaddr + ufs_last_byte(dir, n);
+ de = (struct ufs_dir_entry *)kaddr;
+ kaddr += PAGE_SIZE - reclen;
+ while ((char *)de <= kaddr) {
+ if ((char *)de == dir_end) {
+ /* We hit i_size */
+ name_len = 0;
+ rec_len = chunk_size;
+ de->d_reclen = cpu_to_fs16(sb, chunk_size);
+ de->d_ino = 0;
+ goto got_it;
+ }
+ if (de->d_reclen == 0) {
+ ufs_error(dir->i_sb, __func__,
+ "zero-length directory entry");
+ err = -EIO;
+ goto out_unlock;
+ }
+ err = -EEXIST;
+ if (ufs_match(sb, namelen, name, de))
+ goto out_unlock;
+ name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
+ rec_len = fs16_to_cpu(sb, de->d_reclen);
+ if (!de->d_ino && rec_len >= reclen)
+ goto got_it;
+ if (rec_len >= name_len + reclen)
+ goto got_it;
+ de = (struct ufs_dir_entry *) ((char *) de + rec_len);
+ }
+ unlock_page(page);
+ ufs_put_page(page);
+ }
+ BUG();
+ return -EINVAL;
+
+got_it:
+ pos = page_offset(page) +
+ (char*)de - (char*)page_address(page);
+ err = ufs_prepare_chunk(page, pos, rec_len);
+ if (err)
+ goto out_unlock;
+ if (de->d_ino) {
+ struct ufs_dir_entry *de1 =
+ (struct ufs_dir_entry *) ((char *) de + name_len);
+ de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
+ de->d_reclen = cpu_to_fs16(sb, name_len);
+
+ de = de1;
+ }
+
+ ufs_set_de_namlen(sb, de, namelen);
+ memcpy(de->d_name, name, namelen + 1);
+ de->d_ino = cpu_to_fs32(sb, inode->i_ino);
+ ufs_set_de_type(sb, de, inode->i_mode);
+
+ ufs_commit_chunk(page, pos, rec_len);
+ dir->i_mtime = inode_set_ctime_current(dir);
+
+ mark_inode_dirty(dir);
+ err = ufs_handle_dirsync(dir);
+ /* OFFSET_CACHE */
+out_put:
+ ufs_put_page(page);
+out:
+ return err;
+out_unlock:
+ unlock_page(page);
+ goto out_put;
+}
+
+static inline unsigned
+ufs_validate_entry(struct super_block *sb, char *base,
+ unsigned offset, unsigned mask)
+{
+ struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
+ struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
+ while ((char*)p < (char*)de)
+ p = ufs_next_entry(sb, p);
+ return (char *)p - base;
+}
+
+
+/*
+ * This is blatantly stolen from ext2fs
+ */
+static int
+ufs_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 = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
+ bool need_revalidate = !inode_eq_iversion(inode, file->f_version);
+ unsigned flags = UFS_SB(sb)->s_flags;
+
+ UFSD("BEGIN\n");
+
+ if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
+ return 0;
+
+ for ( ; n < npages; n++, offset = 0) {
+ char *kaddr, *limit;
+ struct ufs_dir_entry *de;
+
+ struct page *page = ufs_get_page(inode, n);
+
+ if (IS_ERR(page)) {
+ ufs_error(sb, __func__,
+ "bad page in #%lu",
+ inode->i_ino);
+ ctx->pos += PAGE_SIZE - offset;
+ return -EIO;
+ }
+ kaddr = page_address(page);
+ if (unlikely(need_revalidate)) {
+ if (offset) {
+ offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
+ ctx->pos = (n<<PAGE_SHIFT) + offset;
+ }
+ file->f_version = inode_query_iversion(inode);
+ need_revalidate = false;
+ }
+ de = (struct ufs_dir_entry *)(kaddr+offset);
+ limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
+ for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
+ if (de->d_ino) {
+ unsigned char d_type = DT_UNKNOWN;
+
+ UFSD("filldir(%s,%u)\n", de->d_name,
+ fs32_to_cpu(sb, de->d_ino));
+ UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
+
+ if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
+ d_type = de->d_u.d_44.d_type;
+
+ if (!dir_emit(ctx, de->d_name,
+ ufs_get_de_namlen(sb, de),
+ fs32_to_cpu(sb, de->d_ino),
+ d_type)) {
+ ufs_put_page(page);
+ return 0;
+ }
+ }
+ ctx->pos += fs16_to_cpu(sb, de->d_reclen);
+ }
+ ufs_put_page(page);
+ }
+ return 0;
+}
+
+
+/*
+ * ufs_delete_entry deletes a directory entry by merging it with the
+ * previous entry.
+ */
+int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
+ struct page * page)
+{
+ struct super_block *sb = inode->i_sb;
+ char *kaddr = page_address(page);
+ unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
+ unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
+ loff_t pos;
+ struct ufs_dir_entry *pde = NULL;
+ struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
+ int err;
+
+ UFSD("ENTER\n");
+
+ UFSD("ino %u, reclen %u, namlen %u, name %s\n",
+ fs32_to_cpu(sb, de->d_ino),
+ fs16_to_cpu(sb, de->d_reclen),
+ ufs_get_de_namlen(sb, de), de->d_name);
+
+ while ((char*)de < (char*)dir) {
+ if (de->d_reclen == 0) {
+ ufs_error(inode->i_sb, __func__,
+ "zero-length directory entry");
+ err = -EIO;
+ goto out;
+ }
+ pde = de;
+ de = ufs_next_entry(sb, de);
+ }
+ if (pde)
+ from = (char*)pde - (char*)page_address(page);
+
+ pos = page_offset(page) + from;
+ lock_page(page);
+ err = ufs_prepare_chunk(page, pos, to - from);
+ BUG_ON(err);
+ if (pde)
+ pde->d_reclen = cpu_to_fs16(sb, to - from);
+ dir->d_ino = 0;
+ ufs_commit_chunk(page, pos, to - from);
+ inode->i_mtime = inode_set_ctime_current(inode);
+ mark_inode_dirty(inode);
+ err = ufs_handle_dirsync(inode);
+out:
+ ufs_put_page(page);
+ UFSD("EXIT\n");
+ return err;
+}
+
+int ufs_make_empty(struct inode * inode, struct inode *dir)
+{
+ struct super_block * sb = dir->i_sb;
+ struct address_space *mapping = inode->i_mapping;
+ struct page *page = grab_cache_page(mapping, 0);
+ const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
+ struct ufs_dir_entry * de;
+ char *base;
+ int err;
+
+ if (!page)
+ return -ENOMEM;
+
+ err = ufs_prepare_chunk(page, 0, chunk_size);
+ if (err) {
+ unlock_page(page);
+ goto fail;
+ }
+
+ kmap(page);
+ base = (char*)page_address(page);
+ memset(base, 0, PAGE_SIZE);
+
+ de = (struct ufs_dir_entry *) base;
+
+ de->d_ino = cpu_to_fs32(sb, inode->i_ino);
+ ufs_set_de_type(sb, de, inode->i_mode);
+ ufs_set_de_namlen(sb, de, 1);
+ de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
+ strcpy (de->d_name, ".");
+ de = (struct ufs_dir_entry *)
+ ((char *)de + fs16_to_cpu(sb, de->d_reclen));
+ de->d_ino = cpu_to_fs32(sb, dir->i_ino);
+ ufs_set_de_type(sb, de, dir->i_mode);
+ de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
+ ufs_set_de_namlen(sb, de, 2);
+ strcpy (de->d_name, "..");
+ kunmap(page);
+
+ ufs_commit_chunk(page, 0, chunk_size);
+ err = ufs_handle_dirsync(inode);
+fail:
+ put_page(page);
+ return err;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+int ufs_empty_dir(struct inode * inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct page *page = NULL;
+ unsigned long i, npages = dir_pages(inode);
+
+ for (i = 0; i < npages; i++) {
+ char *kaddr;
+ struct ufs_dir_entry *de;
+ page = ufs_get_page(inode, i);
+
+ if (IS_ERR(page))
+ continue;
+
+ kaddr = page_address(page);
+ de = (struct ufs_dir_entry *)kaddr;
+ kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
+
+ while ((char *)de <= kaddr) {
+ if (de->d_reclen == 0) {
+ ufs_error(inode->i_sb, __func__,
+ "zero-length directory entry: "
+ "kaddr=%p, de=%p\n", kaddr, de);
+ goto not_empty;
+ }
+ if (de->d_ino) {
+ u16 namelen=ufs_get_de_namlen(sb, de);
+ /* check for . and .. */
+ if (de->d_name[0] != '.')
+ goto not_empty;
+ if (namelen > 2)
+ goto not_empty;
+ if (namelen < 2) {
+ if (inode->i_ino !=
+ fs32_to_cpu(sb, de->d_ino))
+ goto not_empty;
+ } else if (de->d_name[1] != '.')
+ goto not_empty;
+ }
+ de = ufs_next_entry(sb, de);
+ }
+ ufs_put_page(page);
+ }
+ return 1;
+
+not_empty:
+ ufs_put_page(page);
+ return 0;
+}
+
+const struct file_operations ufs_dir_operations = {
+ .read = generic_read_dir,
+ .iterate_shared = ufs_readdir,
+ .fsync = generic_file_fsync,
+ .llseek = generic_file_llseek,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 09:23:59 +0000