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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /fs/reiserfs/xattr_acl.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/reiserfs/xattr_acl.c')
-rw-r--r-- | fs/reiserfs/xattr_acl.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c new file mode 100644 index 000000000..05f666794 --- /dev/null +++ b/fs/reiserfs/xattr_acl.c @@ -0,0 +1,403 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/capability.h> +#include <linux/fs.h> +#include <linux/posix_acl.h> +#include "reiserfs.h" +#include <linux/errno.h> +#include <linux/pagemap.h> +#include <linux/xattr.h> +#include <linux/slab.h> +#include <linux/posix_acl_xattr.h> +#include "xattr.h" +#include "acl.h" +#include <linux/uaccess.h> + +static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, + struct inode *inode, int type, + struct posix_acl *acl); + + +int +reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) +{ + int error, error2; + struct reiserfs_transaction_handle th; + size_t jcreate_blocks; + int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; + int update_mode = 0; + umode_t mode = inode->i_mode; + + /* + * Pessimism: We can't assume that anything from the xattr root up + * has been created. + */ + + jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + + reiserfs_xattr_nblocks(inode, size) * 2; + + reiserfs_write_lock(inode->i_sb); + error = journal_begin(&th, inode->i_sb, jcreate_blocks); + reiserfs_write_unlock(inode->i_sb); + if (error == 0) { + if (type == ACL_TYPE_ACCESS && acl) { + error = posix_acl_update_mode(inode, &mode, &acl); + if (error) + goto unlock; + update_mode = 1; + } + error = __reiserfs_set_acl(&th, inode, type, acl); + if (!error && update_mode) + inode->i_mode = mode; +unlock: + reiserfs_write_lock(inode->i_sb); + error2 = journal_end(&th); + reiserfs_write_unlock(inode->i_sb); + if (error2) + error = error2; + } + + return error; +} + +/* + * Convert from filesystem to in-memory representation. + */ +static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) +{ + const char *end = (char *)value + size; + int n, count; + struct posix_acl *acl; + + if (!value) + return NULL; + if (size < sizeof(reiserfs_acl_header)) + return ERR_PTR(-EINVAL); + if (((reiserfs_acl_header *) value)->a_version != + cpu_to_le32(REISERFS_ACL_VERSION)) + return ERR_PTR(-EINVAL); + value = (char *)value + sizeof(reiserfs_acl_header); + count = reiserfs_acl_count(size); + if (count < 0) + return ERR_PTR(-EINVAL); + if (count == 0) + return NULL; + acl = posix_acl_alloc(count, GFP_NOFS); + if (!acl) + return ERR_PTR(-ENOMEM); + for (n = 0; n < count; n++) { + reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; + if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) + goto fail; + acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); + acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); + switch (acl->a_entries[n].e_tag) { + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + value = (char *)value + + sizeof(reiserfs_acl_entry_short); + break; + + case ACL_USER: + value = (char *)value + sizeof(reiserfs_acl_entry); + if ((char *)value > end) + goto fail; + acl->a_entries[n].e_uid = + make_kuid(&init_user_ns, + le32_to_cpu(entry->e_id)); + break; + case ACL_GROUP: + value = (char *)value + sizeof(reiserfs_acl_entry); + if ((char *)value > end) + goto fail; + acl->a_entries[n].e_gid = + make_kgid(&init_user_ns, + le32_to_cpu(entry->e_id)); + break; + + default: + goto fail; + } + } + if (value != end) + goto fail; + return acl; + +fail: + posix_acl_release(acl); + return ERR_PTR(-EINVAL); +} + +/* + * Convert from in-memory to filesystem representation. + */ +static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) +{ + reiserfs_acl_header *ext_acl; + char *e; + int n; + + *size = reiserfs_acl_size(acl->a_count); + ext_acl = kmalloc(sizeof(reiserfs_acl_header) + + acl->a_count * + sizeof(reiserfs_acl_entry), + GFP_NOFS); + if (!ext_acl) + return ERR_PTR(-ENOMEM); + ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); + e = (char *)ext_acl + sizeof(reiserfs_acl_header); + for (n = 0; n < acl->a_count; n++) { + const struct posix_acl_entry *acl_e = &acl->a_entries[n]; + reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; + entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); + entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); + switch (acl->a_entries[n].e_tag) { + case ACL_USER: + entry->e_id = cpu_to_le32( + from_kuid(&init_user_ns, acl_e->e_uid)); + e += sizeof(reiserfs_acl_entry); + break; + case ACL_GROUP: + entry->e_id = cpu_to_le32( + from_kgid(&init_user_ns, acl_e->e_gid)); + e += sizeof(reiserfs_acl_entry); + break; + + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + e += sizeof(reiserfs_acl_entry_short); + break; + + default: + goto fail; + } + } + return (char *)ext_acl; + +fail: + kfree(ext_acl); + return ERR_PTR(-EINVAL); +} + +/* + * Inode operation get_posix_acl(). + * + * inode->i_mutex: down + * BKL held [before 2.5.x] + */ +struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) +{ + char *name, *value; + struct posix_acl *acl; + int size; + int retval; + + switch (type) { + case ACL_TYPE_ACCESS: + name = XATTR_NAME_POSIX_ACL_ACCESS; + break; + case ACL_TYPE_DEFAULT: + name = XATTR_NAME_POSIX_ACL_DEFAULT; + break; + default: + BUG(); + } + + size = reiserfs_xattr_get(inode, name, NULL, 0); + if (size < 0) { + if (size == -ENODATA || size == -ENOSYS) + return NULL; + return ERR_PTR(size); + } + + value = kmalloc(size, GFP_NOFS); + if (!value) + return ERR_PTR(-ENOMEM); + + retval = reiserfs_xattr_get(inode, name, value, size); + if (retval == -ENODATA || retval == -ENOSYS) { + /* + * This shouldn't actually happen as it should have + * been caught above.. but just in case + */ + acl = NULL; + } else if (retval < 0) { + acl = ERR_PTR(retval); + } else { + acl = reiserfs_posix_acl_from_disk(value, retval); + } + + kfree(value); + return acl; +} + +/* + * Inode operation set_posix_acl(). + * + * inode->i_mutex: down + * BKL held [before 2.5.x] + */ +static int +__reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, + int type, struct posix_acl *acl) +{ + char *name; + void *value = NULL; + size_t size = 0; + int error; + + switch (type) { + case ACL_TYPE_ACCESS: + name = XATTR_NAME_POSIX_ACL_ACCESS; + break; + case ACL_TYPE_DEFAULT: + name = XATTR_NAME_POSIX_ACL_DEFAULT; + if (!S_ISDIR(inode->i_mode)) + return acl ? -EACCES : 0; + break; + default: + return -EINVAL; + } + + if (acl) { + value = reiserfs_posix_acl_to_disk(acl, &size); + if (IS_ERR(value)) + return (int)PTR_ERR(value); + } + + error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); + + /* + * Ensure that the inode gets dirtied if we're only using + * the mode bits and an old ACL didn't exist. We don't need + * to check if the inode is hashed here since we won't get + * called by reiserfs_inherit_default_acl(). + */ + if (error == -ENODATA) { + error = 0; + if (type == ACL_TYPE_ACCESS) { + inode->i_ctime = current_time(inode); + mark_inode_dirty(inode); + } + } + + kfree(value); + + if (!error) + set_cached_acl(inode, type, acl); + + return error; +} + +/* + * dir->i_mutex: locked, + * inode is new and not released into the wild yet + */ +int +reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, + struct inode *dir, struct dentry *dentry, + struct inode *inode) +{ + struct posix_acl *default_acl, *acl; + int err = 0; + + /* ACLs only get applied to files and directories */ + if (S_ISLNK(inode->i_mode)) + return 0; + + /* + * ACLs can only be used on "new" objects, so if it's an old object + * there is nothing to inherit from + */ + if (get_inode_sd_version(dir) == STAT_DATA_V1) + goto apply_umask; + + /* + * Don't apply ACLs to objects in the .reiserfs_priv tree.. This + * would be useless since permissions are ignored, and a pain because + * it introduces locking cycles + */ + if (IS_PRIVATE(inode)) + goto apply_umask; + + err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); + if (err) + return err; + + if (default_acl) { + err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, + default_acl); + posix_acl_release(default_acl); + } + if (acl) { + if (!err) + err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, + acl); + posix_acl_release(acl); + } + + return err; + +apply_umask: + /* no ACL, apply umask */ + inode->i_mode &= ~current_umask(); + return err; +} + +/* This is used to cache the default acl before a new object is created. + * The biggest reason for this is to get an idea of how many blocks will + * actually be required for the create operation if we must inherit an ACL. + * An ACL write can add up to 3 object creations and an additional file write + * so we'd prefer not to reserve that many blocks in the journal if we can. + * It also has the advantage of not loading the ACL with a transaction open, + * this may seem silly, but if the owner of the directory is doing the + * creation, the ACL may not be loaded since the permissions wouldn't require + * it. + * We return the number of blocks required for the transaction. + */ +int reiserfs_cache_default_acl(struct inode *inode) +{ + struct posix_acl *acl; + int nblocks = 0; + + if (IS_PRIVATE(inode)) + return 0; + + acl = get_acl(inode, ACL_TYPE_DEFAULT); + + if (acl && !IS_ERR(acl)) { + int size = reiserfs_acl_size(acl->a_count); + + /* Other xattrs can be created during inode creation. We don't + * want to claim too many blocks, so we check to see if we + * we need to create the tree to the xattrs, and then we + * just want two files. */ + nblocks = reiserfs_xattr_jcreate_nblocks(inode); + nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); + + REISERFS_I(inode)->i_flags |= i_has_xattr_dir; + + /* We need to account for writes + bitmaps for two files */ + nblocks += reiserfs_xattr_nblocks(inode, size) * 4; + posix_acl_release(acl); + } + + return nblocks; +} + +/* + * Called under i_mutex + */ +int reiserfs_acl_chmod(struct inode *inode) +{ + if (IS_PRIVATE(inode)) + return 0; + if (get_inode_sd_version(inode) == STAT_DATA_V1 || + !reiserfs_posixacl(inode->i_sb)) + return 0; + + return posix_acl_chmod(inode, inode->i_mode); +} |