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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /fs/ext2/namei.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/ext2/namei.c')
-rw-r--r-- | fs/ext2/namei.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c new file mode 100644 index 000000000..9125eab85 --- /dev/null +++ b/fs/ext2/namei.c @@ -0,0 +1,443 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ext2/namei.c + * + * Rewrite to pagecache. Almost all code had been changed, so blame me + * if the things go wrong. Please, send bug reports to + * viro@parcelfarce.linux.theplanet.co.uk + * + * Stuff here is basically a glue between the VFS and generic UNIXish + * filesystem that keeps everything in pagecache. All knowledge of the + * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable + * and it's easier to debug that way. In principle we might want to + * generalize that a bit and turn it into a library. Or not. + * + * The only non-static object here is ext2_dir_inode_operations. + * + * TODO: get rid of kmap() use, add readahead. + * + * 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/namei.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + */ + +#include <linux/pagemap.h> +#include <linux/quotaops.h> +#include "ext2.h" +#include "xattr.h" +#include "acl.h" + +static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode) +{ + int err = ext2_add_link(dentry, inode); + if (!err) { + d_instantiate_new(dentry, inode); + return 0; + } + inode_dec_link_count(inode); + discard_new_inode(inode); + return err; +} + +/* + * Methods themselves. + */ + +static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags) +{ + struct inode * inode; + ino_t ino; + int res; + + if (dentry->d_name.len > EXT2_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + res = ext2_inode_by_name(dir, &dentry->d_name, &ino); + if (res) { + if (res != -ENOENT) + return ERR_PTR(res); + inode = NULL; + } else { + inode = ext2_iget(dir->i_sb, ino); + if (inode == ERR_PTR(-ESTALE)) { + ext2_error(dir->i_sb, __func__, + "deleted inode referenced: %lu", + (unsigned long) ino); + return ERR_PTR(-EIO); + } + } + return d_splice_alias(inode, dentry); +} + +struct dentry *ext2_get_parent(struct dentry *child) +{ + ino_t ino; + int res; + + res = ext2_inode_by_name(d_inode(child), &dotdot_name, &ino); + if (res) + return ERR_PTR(res); + + return d_obtain_alias(ext2_iget(child->d_sb, ino)); +} + +/* + * By the time this is called, we already have created + * the directory cache entry for the new file, but it + * is so far negative - it has no inode. + * + * If the create succeeds, we fill in the inode information + * with d_instantiate(). + */ +static int ext2_create (struct user_namespace * mnt_userns, + struct inode * dir, struct dentry * dentry, + umode_t mode, bool excl) +{ + struct inode *inode; + int err; + + err = dquot_initialize(dir); + if (err) + return err; + + inode = ext2_new_inode(dir, mode, &dentry->d_name); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + ext2_set_file_ops(inode); + mark_inode_dirty(inode); + return ext2_add_nondir(dentry, inode); +} + +static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct file *file, umode_t mode) +{ + struct inode *inode = ext2_new_inode(dir, mode, NULL); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + ext2_set_file_ops(inode); + mark_inode_dirty(inode); + d_tmpfile(file, inode); + unlock_new_inode(inode); + return finish_open_simple(file, 0); +} + +static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir, + struct dentry *dentry, umode_t mode, dev_t rdev) +{ + struct inode * inode; + int err; + + err = dquot_initialize(dir); + if (err) + return err; + + inode = ext2_new_inode (dir, mode, &dentry->d_name); + err = PTR_ERR(inode); + if (!IS_ERR(inode)) { + init_special_inode(inode, inode->i_mode, rdev); + inode->i_op = &ext2_special_inode_operations; + mark_inode_dirty(inode); + err = ext2_add_nondir(dentry, inode); + } + return err; +} + +static int ext2_symlink (struct user_namespace * mnt_userns, struct inode * dir, + struct dentry * dentry, const char * symname) +{ + struct super_block * sb = dir->i_sb; + int err = -ENAMETOOLONG; + unsigned l = strlen(symname)+1; + struct inode * inode; + + if (l > sb->s_blocksize) + goto out; + + err = dquot_initialize(dir); + if (err) + goto out; + + inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out; + + if (l > sizeof (EXT2_I(inode)->i_data)) { + /* slow symlink */ + inode->i_op = &ext2_symlink_inode_operations; + inode_nohighmem(inode); + inode->i_mapping->a_ops = &ext2_aops; + err = page_symlink(inode, symname, l); + if (err) + goto out_fail; + } else { + /* fast symlink */ + inode->i_op = &ext2_fast_symlink_inode_operations; + inode->i_link = (char*)EXT2_I(inode)->i_data; + memcpy(inode->i_link, symname, l); + inode->i_size = l-1; + } + mark_inode_dirty(inode); + + err = ext2_add_nondir(dentry, inode); +out: + return err; + +out_fail: + inode_dec_link_count(inode); + discard_new_inode(inode); + goto out; +} + +static int ext2_link (struct dentry * old_dentry, struct inode * dir, + struct dentry *dentry) +{ + struct inode *inode = d_inode(old_dentry); + int err; + + err = dquot_initialize(dir); + if (err) + return err; + + inode->i_ctime = current_time(inode); + inode_inc_link_count(inode); + ihold(inode); + + err = ext2_add_link(dentry, inode); + if (!err) { + d_instantiate(dentry, inode); + return 0; + } + inode_dec_link_count(inode); + iput(inode); + return err; +} + +static int ext2_mkdir(struct user_namespace * mnt_userns, + struct inode * dir, struct dentry * dentry, umode_t mode) +{ + struct inode * inode; + int err; + + err = dquot_initialize(dir); + if (err) + return err; + + inode_inc_link_count(dir); + + inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_dir; + + inode->i_op = &ext2_dir_inode_operations; + inode->i_fop = &ext2_dir_operations; + inode->i_mapping->a_ops = &ext2_aops; + + inode_inc_link_count(inode); + + err = ext2_make_empty(inode, dir); + if (err) + goto out_fail; + + err = ext2_add_link(dentry, inode); + if (err) + goto out_fail; + + d_instantiate_new(dentry, inode); +out: + return err; + +out_fail: + inode_dec_link_count(inode); + inode_dec_link_count(inode); + discard_new_inode(inode); +out_dir: + inode_dec_link_count(dir); + goto out; +} + +static int ext2_unlink(struct inode * dir, struct dentry *dentry) +{ + struct inode * inode = d_inode(dentry); + struct ext2_dir_entry_2 * de; + struct page * page; + void *page_addr; + int err; + + err = dquot_initialize(dir); + if (err) + goto out; + + de = ext2_find_entry(dir, &dentry->d_name, &page, &page_addr); + if (IS_ERR(de)) { + err = PTR_ERR(de); + goto out; + } + + err = ext2_delete_entry (de, page, page_addr); + ext2_put_page(page, page_addr); + if (err) + goto out; + + inode->i_ctime = dir->i_ctime; + inode_dec_link_count(inode); + err = 0; +out: + return err; +} + +static int ext2_rmdir (struct inode * dir, struct dentry *dentry) +{ + struct inode * inode = d_inode(dentry); + int err = -ENOTEMPTY; + + if (ext2_empty_dir(inode)) { + err = ext2_unlink(dir, dentry); + if (!err) { + inode->i_size = 0; + inode_dec_link_count(inode); + inode_dec_link_count(dir); + } + } + return err; +} + +static int ext2_rename (struct user_namespace * mnt_userns, + struct inode * old_dir, struct dentry * old_dentry, + struct inode * new_dir, struct dentry * new_dentry, + unsigned int flags) +{ + struct inode * old_inode = d_inode(old_dentry); + struct inode * new_inode = d_inode(new_dentry); + struct page * dir_page = NULL; + void *dir_page_addr; + struct ext2_dir_entry_2 * dir_de = NULL; + struct page * old_page; + void *old_page_addr; + struct ext2_dir_entry_2 * old_de; + int err; + + if (flags & ~RENAME_NOREPLACE) + return -EINVAL; + + err = dquot_initialize(old_dir); + if (err) + goto out; + + err = dquot_initialize(new_dir); + if (err) + goto out; + + old_de = ext2_find_entry(old_dir, &old_dentry->d_name, &old_page, + &old_page_addr); + if (IS_ERR(old_de)) { + err = PTR_ERR(old_de); + goto out; + } + + if (S_ISDIR(old_inode->i_mode)) { + err = -EIO; + dir_de = ext2_dotdot(old_inode, &dir_page, &dir_page_addr); + if (!dir_de) + goto out_old; + } + + if (new_inode) { + void *page_addr; + struct page *new_page; + struct ext2_dir_entry_2 *new_de; + + err = -ENOTEMPTY; + if (dir_de && !ext2_empty_dir (new_inode)) + goto out_dir; + + new_de = ext2_find_entry(new_dir, &new_dentry->d_name, + &new_page, &page_addr); + if (IS_ERR(new_de)) { + err = PTR_ERR(new_de); + goto out_dir; + } + ext2_set_link(new_dir, new_de, new_page, page_addr, old_inode, 1); + ext2_put_page(new_page, page_addr); + new_inode->i_ctime = current_time(new_inode); + if (dir_de) + drop_nlink(new_inode); + inode_dec_link_count(new_inode); + } else { + err = ext2_add_link(new_dentry, old_inode); + if (err) + goto out_dir; + if (dir_de) + inode_inc_link_count(new_dir); + } + + /* + * Like most other Unix systems, set the ctime for inodes on a + * rename. + */ + old_inode->i_ctime = current_time(old_inode); + mark_inode_dirty(old_inode); + + ext2_delete_entry(old_de, old_page, old_page_addr); + + if (dir_de) { + if (old_dir != new_dir) + ext2_set_link(old_inode, dir_de, dir_page, + dir_page_addr, new_dir, 0); + + ext2_put_page(dir_page, dir_page_addr); + inode_dec_link_count(old_dir); + } + + ext2_put_page(old_page, old_page_addr); + return 0; + +out_dir: + if (dir_de) + ext2_put_page(dir_page, dir_page_addr); +out_old: + ext2_put_page(old_page, old_page_addr); +out: + return err; +} + +const struct inode_operations ext2_dir_inode_operations = { + .create = ext2_create, + .lookup = ext2_lookup, + .link = ext2_link, + .unlink = ext2_unlink, + .symlink = ext2_symlink, + .mkdir = ext2_mkdir, + .rmdir = ext2_rmdir, + .mknod = ext2_mknod, + .rename = ext2_rename, + .listxattr = ext2_listxattr, + .getattr = ext2_getattr, + .setattr = ext2_setattr, + .get_acl = ext2_get_acl, + .set_acl = ext2_set_acl, + .tmpfile = ext2_tmpfile, + .fileattr_get = ext2_fileattr_get, + .fileattr_set = ext2_fileattr_set, +}; + +const struct inode_operations ext2_special_inode_operations = { + .listxattr = ext2_listxattr, + .getattr = ext2_getattr, + .setattr = ext2_setattr, + .get_acl = ext2_get_acl, + .set_acl = ext2_set_acl, +}; 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