| /* |
| * linux/fs/reiserfs/xattr.c |
| * |
| * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com> |
| * |
| */ |
| |
| /* |
| * In order to implement EA/ACLs in a clean, backwards compatible manner, |
| * they are implemented as files in a "private" directory. |
| * Each EA is in it's own file, with the directory layout like so (/ is assumed |
| * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory, |
| * directories named using the capital-hex form of the objectid and |
| * generation number are used. Inside each directory are individual files |
| * named with the name of the extended attribute. |
| * |
| * So, for objectid 12648430, we could have: |
| * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access |
| * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default |
| * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type |
| * .. or similar. |
| * |
| * The file contents are the text of the EA. The size is known based on the |
| * stat data describing the file. |
| * |
| * In the case of system.posix_acl_access and system.posix_acl_default, since |
| * these are special cases for filesystem ACLs, they are interpreted by the |
| * kernel, in addition, they are negatively and positively cached and attached |
| * to the inode so that unnecessary lookups are avoided. |
| * |
| * Locking works like so: |
| * Directory components (xattr root, xattr dir) are protectd by their i_mutex. |
| * The xattrs themselves are protected by the xattr_sem. |
| */ |
| |
| #include <linux/reiserfs_fs.h> |
| #include <linux/capability.h> |
| #include <linux/dcache.h> |
| #include <linux/namei.h> |
| #include <linux/errno.h> |
| #include <linux/gfp.h> |
| #include <linux/fs.h> |
| #include <linux/file.h> |
| #include <linux/pagemap.h> |
| #include <linux/xattr.h> |
| #include <linux/reiserfs_xattr.h> |
| #include <linux/reiserfs_acl.h> |
| #include <asm/uaccess.h> |
| #include <net/checksum.h> |
| #include <linux/stat.h> |
| #include <linux/quotaops.h> |
| #include <linux/security.h> |
| |
| #define PRIVROOT_NAME ".reiserfs_priv" |
| #define XAROOT_NAME "xattrs" |
| |
| |
| /* Helpers for inode ops. We do this so that we don't have all the VFS |
| * overhead and also for proper i_mutex annotation. |
| * dir->i_mutex must be held for all of them. */ |
| #ifdef CONFIG_REISERFS_FS_XATTR |
| static int xattr_create(struct inode *dir, struct dentry *dentry, int mode) |
| { |
| BUG_ON(!mutex_is_locked(&dir->i_mutex)); |
| return dir->i_op->create(dir, dentry, mode, NULL); |
| } |
| #endif |
| |
| static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
| { |
| BUG_ON(!mutex_is_locked(&dir->i_mutex)); |
| return dir->i_op->mkdir(dir, dentry, mode); |
| } |
| |
| /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr |
| * mutation ops aren't called during rename or splace, which are the |
| * only other users of I_MUTEX_CHILD. It violates the ordering, but that's |
| * better than allocating another subclass just for this code. */ |
| static int xattr_unlink(struct inode *dir, struct dentry *dentry) |
| { |
| int error; |
| BUG_ON(!mutex_is_locked(&dir->i_mutex)); |
| |
| reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex, |
| I_MUTEX_CHILD, dir->i_sb); |
| error = dir->i_op->unlink(dir, dentry); |
| mutex_unlock(&dentry->d_inode->i_mutex); |
| |
| if (!error) |
| d_delete(dentry); |
| return error; |
| } |
| |
| static int xattr_rmdir(struct inode *dir, struct dentry *dentry) |
| { |
| int error; |
| BUG_ON(!mutex_is_locked(&dir->i_mutex)); |
| |
| reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex, |
| I_MUTEX_CHILD, dir->i_sb); |
| dentry_unhash(dentry); |
| error = dir->i_op->rmdir(dir, dentry); |
| if (!error) |
| dentry->d_inode->i_flags |= S_DEAD; |
| mutex_unlock(&dentry->d_inode->i_mutex); |
| if (!error) |
| d_delete(dentry); |
| dput(dentry); |
| |
| return error; |
| } |
| |
| #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE) |
| |
| static struct dentry *open_xa_root(struct super_block *sb, int flags) |
| { |
| struct dentry *privroot = REISERFS_SB(sb)->priv_root; |
| struct dentry *xaroot; |
| if (!privroot->d_inode) |
| return ERR_PTR(-ENODATA); |
| |
| mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR); |
| |
| xaroot = dget(REISERFS_SB(sb)->xattr_root); |
| if (!xaroot) |
| xaroot = ERR_PTR(-ENODATA); |
| else if (!xaroot->d_inode) { |
| int err = -ENODATA; |
| if (xattr_may_create(flags)) |
| err = xattr_mkdir(privroot->d_inode, xaroot, 0700); |
| if (err) { |
| dput(xaroot); |
| xaroot = ERR_PTR(err); |
| } |
| } |
| |
| mutex_unlock(&privroot->d_inode->i_mutex); |
| return xaroot; |
| } |
| |
| static struct dentry *open_xa_dir(const struct inode *inode, int flags) |
| { |
| struct dentry *xaroot, *xadir; |
| char namebuf[17]; |
| |
| xaroot = open_xa_root(inode->i_sb, flags); |
| if (IS_ERR(xaroot)) |
| return xaroot; |
| |
| snprintf(namebuf, sizeof(namebuf), "%X.%X", |
| le32_to_cpu(INODE_PKEY(inode)->k_objectid), |
| inode->i_generation); |
| |
| mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR); |
| |
| xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf)); |
| if (!IS_ERR(xadir) && !xadir->d_inode) { |
| int err = -ENODATA; |
| if (xattr_may_create(flags)) |
| err = xattr_mkdir(xaroot->d_inode, xadir, 0700); |
| if (err) { |
| dput(xadir); |
| xadir = ERR_PTR(err); |
| } |
| } |
| |
| mutex_unlock(&xaroot->d_inode->i_mutex); |
| dput(xaroot); |
| return xadir; |
| } |
| |
| /* The following are side effects of other operations that aren't explicitly |
| * modifying extended attributes. This includes operations such as permissions |
| * or ownership changes, object deletions, etc. */ |
| struct reiserfs_dentry_buf { |
| struct dentry *xadir; |
| int count; |
| struct dentry *dentries[8]; |
| }; |
| |
| static int |
| fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset, |
| u64 ino, unsigned int d_type) |
| { |
| struct reiserfs_dentry_buf *dbuf = buf; |
| struct dentry *dentry; |
| WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex)); |
| |
| if (dbuf->count == ARRAY_SIZE(dbuf->dentries)) |
| return -ENOSPC; |
| |
| if (name[0] == '.' && (name[1] == '\0' || |
| (name[1] == '.' && name[2] == '\0'))) |
| return 0; |
| |
| dentry = lookup_one_len(name, dbuf->xadir, namelen); |
| if (IS_ERR(dentry)) { |
| return PTR_ERR(dentry); |
| } else if (!dentry->d_inode) { |
| /* A directory entry exists, but no file? */ |
| reiserfs_error(dentry->d_sb, "xattr-20003", |
| "Corrupted directory: xattr %s listed but " |
| "not found for file %s.\n", |
| dentry->d_name.name, dbuf->xadir->d_name.name); |
| dput(dentry); |
| return -EIO; |
| } |
| |
| dbuf->dentries[dbuf->count++] = dentry; |
| return 0; |
| } |
| |
| static void |
| cleanup_dentry_buf(struct reiserfs_dentry_buf *buf) |
| { |
| int i; |
| for (i = 0; i < buf->count; i++) |
| if (buf->dentries[i]) |
| dput(buf->dentries[i]); |
| } |
| |
| static int reiserfs_for_each_xattr(struct inode *inode, |
| int (*action)(struct dentry *, void *), |
| void *data) |
| { |
| struct dentry *dir; |
| int i, err = 0; |
| loff_t pos = 0; |
| struct reiserfs_dentry_buf buf = { |
| .count = 0, |
| }; |
| |
| /* Skip out, an xattr has no xattrs associated with it */ |
| if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1) |
| return 0; |
| |
| reiserfs_write_unlock(inode->i_sb); |
| dir = open_xa_dir(inode, XATTR_REPLACE); |
| if (IS_ERR(dir)) { |
| err = PTR_ERR(dir); |
| reiserfs_write_lock(inode->i_sb); |
| goto out; |
| } else if (!dir->d_inode) { |
| err = 0; |
| reiserfs_write_lock(inode->i_sb); |
| goto out_dir; |
| } |
| |
| mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR); |
| |
| reiserfs_write_lock(inode->i_sb); |
| |
| buf.xadir = dir; |
| err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos); |
| while ((err == 0 || err == -ENOSPC) && buf.count) { |
| err = 0; |
| |
| for (i = 0; i < buf.count && buf.dentries[i]; i++) { |
| int lerr = 0; |
| struct dentry *dentry = buf.dentries[i]; |
| |
| if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode)) |
| lerr = action(dentry, data); |
| |
| dput(dentry); |
| buf.dentries[i] = NULL; |
| err = lerr ?: err; |
| } |
| buf.count = 0; |
| if (!err) |
| err = reiserfs_readdir_dentry(dir, &buf, |
| fill_with_dentries, &pos); |
| } |
| mutex_unlock(&dir->d_inode->i_mutex); |
| |
| /* Clean up after a failed readdir */ |
| cleanup_dentry_buf(&buf); |
| |
| if (!err) { |
| /* We start a transaction here to avoid a ABBA situation |
| * between the xattr root's i_mutex and the journal lock. |
| * This doesn't incur much additional overhead since the |
| * new transaction will just nest inside the |
| * outer transaction. */ |
| int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 + |
| 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb); |
| struct reiserfs_transaction_handle th; |
| err = journal_begin(&th, inode->i_sb, blocks); |
| if (!err) { |
| int jerror; |
| reiserfs_mutex_lock_nested_safe( |
| &dir->d_parent->d_inode->i_mutex, |
| I_MUTEX_XATTR, inode->i_sb); |
| err = action(dir, data); |
| jerror = journal_end(&th, inode->i_sb, blocks); |
| mutex_unlock(&dir->d_parent->d_inode->i_mutex); |
| err = jerror ?: err; |
| } |
| } |
| out_dir: |
| dput(dir); |
| out: |
| /* -ENODATA isn't an error */ |
| if (err == -ENODATA) |
| err = 0; |
| return err; |
| } |
| |
| static int delete_one_xattr(struct dentry *dentry, void *data) |
| { |
| struct inode *dir = dentry->d_parent->d_inode; |
| |
| /* This is the xattr dir, handle specially. */ |
| if (S_ISDIR(dentry->d_inode->i_mode)) |
| return xattr_rmdir(dir, dentry); |
| |
| return xattr_unlink(dir, dentry); |
| } |
| |
| static int chown_one_xattr(struct dentry *dentry, void *data) |
| { |
| struct iattr *attrs = data; |
| return reiserfs_setattr(dentry, attrs); |
| } |
| |
| /* No i_mutex, but the inode is unconnected. */ |
| int reiserfs_delete_xattrs(struct inode *inode) |
| { |
| int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL); |
| if (err) |
| reiserfs_warning(inode->i_sb, "jdm-20004", |
| "Couldn't delete all xattrs (%d)\n", err); |
| return err; |
| } |
| |
| /* inode->i_mutex: down */ |
| int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs) |
| { |
| int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs); |
| if (err) |
| reiserfs_warning(inode->i_sb, "jdm-20007", |
| "Couldn't chown all xattrs (%d)\n", err); |
| return err; |
| } |
| |
| #ifdef CONFIG_REISERFS_FS_XATTR |
| /* Returns a dentry corresponding to a specific extended attribute file |
| * for the inode. If flags allow, the file is created. Otherwise, a |
| * valid or negative dentry, or an error is returned. */ |
| static struct dentry *xattr_lookup(struct inode *inode, const char *name, |
| int flags) |
| { |
| struct dentry *xadir, *xafile; |
| int err = 0; |
| |
| xadir = open_xa_dir(inode, flags); |
| if (IS_ERR(xadir)) |
| return ERR_CAST(xadir); |
| |
| mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR); |
| xafile = lookup_one_len(name, xadir, strlen(name)); |
| if (IS_ERR(xafile)) { |
| err = PTR_ERR(xafile); |
| goto out; |
| } |
| |
| if (xafile->d_inode && (flags & XATTR_CREATE)) |
| err = -EEXIST; |
| |
| if (!xafile->d_inode) { |
| err = -ENODATA; |
| if (xattr_may_create(flags)) |
| err = xattr_create(xadir->d_inode, xafile, |
| 0700|S_IFREG); |
| } |
| |
| if (err) |
| dput(xafile); |
| out: |
| mutex_unlock(&xadir->d_inode->i_mutex); |
| dput(xadir); |
| if (err) |
| return ERR_PTR(err); |
| return xafile; |
| } |
| |
| /* Internal operations on file data */ |
| static inline void reiserfs_put_page(struct page *page) |
| { |
| kunmap(page); |
| page_cache_release(page); |
| } |
| |
| static struct page *reiserfs_get_page(struct inode *dir, size_t n) |
| { |
| struct address_space *mapping = dir->i_mapping; |
| struct page *page; |
| /* We can deadlock if we try to free dentries, |
| and an unlink/rmdir has just occured - GFP_NOFS avoids this */ |
| mapping_set_gfp_mask(mapping, GFP_NOFS); |
| page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL); |
| if (!IS_ERR(page)) { |
| kmap(page); |
| if (PageError(page)) |
| goto fail; |
| } |
| return page; |
| |
| fail: |
| reiserfs_put_page(page); |
| return ERR_PTR(-EIO); |
| } |
| |
| static inline __u32 xattr_hash(const char *msg, int len) |
| { |
| return csum_partial(msg, len, 0); |
| } |
| |
| int reiserfs_commit_write(struct file *f, struct page *page, |
| unsigned from, unsigned to); |
| |
| static void update_ctime(struct inode *inode) |
| { |
| struct timespec now = current_fs_time(inode->i_sb); |
| if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink || |
| timespec_equal(&inode->i_ctime, &now)) |
| return; |
| |
| inode->i_ctime = CURRENT_TIME_SEC; |
| mark_inode_dirty(inode); |
| } |
| |
| static int lookup_and_delete_xattr(struct inode *inode, const char *name) |
| { |
| int err = 0; |
| struct dentry *dentry, *xadir; |
| |
| xadir = open_xa_dir(inode, XATTR_REPLACE); |
| if (IS_ERR(xadir)) |
| return PTR_ERR(xadir); |
| |
| mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR); |
| dentry = lookup_one_len(name, xadir, strlen(name)); |
| if (IS_ERR(dentry)) { |
| err = PTR_ERR(dentry); |
| goto out_dput; |
| } |
| |
| if (dentry->d_inode) { |
| reiserfs_write_lock(inode->i_sb); |
| err = xattr_unlink(xadir->d_inode, dentry); |
| reiserfs_write_unlock(inode->i_sb); |
| update_ctime(inode); |
| } |
| |
| dput(dentry); |
| out_dput: |
| mutex_unlock(&xadir->d_inode->i_mutex); |
| dput(xadir); |
| return err; |
| } |
| |
| |
| /* Generic extended attribute operations that can be used by xa plugins */ |
| |
| /* |
| * inode->i_mutex: down |
| */ |
| int |
| reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th, |
| struct inode *inode, const char *name, |
| const void *buffer, size_t buffer_size, int flags) |
| { |
| int err = 0; |
| struct dentry *dentry; |
| struct page *page; |
| char *data; |
| size_t file_pos = 0; |
| size_t buffer_pos = 0; |
| size_t new_size; |
| __u32 xahash = 0; |
| |
| if (get_inode_sd_version(inode) == STAT_DATA_V1) |
| return -EOPNOTSUPP; |
| |
| reiserfs_write_unlock(inode->i_sb); |
| |
| if (!buffer) { |
| err = lookup_and_delete_xattr(inode, name); |
| reiserfs_write_lock(inode->i_sb); |
| return err; |
| } |
| |
| dentry = xattr_lookup(inode, name, flags); |
| if (IS_ERR(dentry)) { |
| reiserfs_write_lock(inode->i_sb); |
| return PTR_ERR(dentry); |
| } |
| |
| down_write(&REISERFS_I(inode)->i_xattr_sem); |
| |
| reiserfs_write_lock(inode->i_sb); |
| |
| xahash = xattr_hash(buffer, buffer_size); |
| while (buffer_pos < buffer_size || buffer_pos == 0) { |
| size_t chunk; |
| size_t skip = 0; |
| size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1)); |
| if (buffer_size - buffer_pos > PAGE_CACHE_SIZE) |
| chunk = PAGE_CACHE_SIZE; |
| else |
| chunk = buffer_size - buffer_pos; |
| |
| page = reiserfs_get_page(dentry->d_inode, file_pos); |
| if (IS_ERR(page)) { |
| err = PTR_ERR(page); |
| goto out_unlock; |
| } |
| |
| lock_page(page); |
| data = page_address(page); |
| |
| if (file_pos == 0) { |
| struct reiserfs_xattr_header *rxh; |
| skip = file_pos = sizeof(struct reiserfs_xattr_header); |
| if (chunk + skip > PAGE_CACHE_SIZE) |
| chunk = PAGE_CACHE_SIZE - skip; |
| rxh = (struct reiserfs_xattr_header *)data; |
| rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC); |
| rxh->h_hash = cpu_to_le32(xahash); |
| } |
| |
| err = __reiserfs_write_begin(page, page_offset, chunk + skip); |
| if (!err) { |
| if (buffer) |
| memcpy(data + skip, buffer + buffer_pos, chunk); |
| err = reiserfs_commit_write(NULL, page, page_offset, |
| page_offset + chunk + |
| skip); |
| } |
| unlock_page(page); |
| reiserfs_put_page(page); |
| buffer_pos += chunk; |
| file_pos += chunk; |
| skip = 0; |
| if (err || buffer_size == 0 || !buffer) |
| break; |
| } |
| |
| new_size = buffer_size + sizeof(struct reiserfs_xattr_header); |
| if (!err && new_size < i_size_read(dentry->d_inode)) { |
| struct iattr newattrs = { |
| .ia_ctime = current_fs_time(inode->i_sb), |
| .ia_size = new_size, |
| .ia_valid = ATTR_SIZE | ATTR_CTIME, |
| }; |
| |
| reiserfs_write_unlock(inode->i_sb); |
| mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR); |
| down_write(&dentry->d_inode->i_alloc_sem); |
| reiserfs_write_lock(inode->i_sb); |
| |
| err = reiserfs_setattr(dentry, &newattrs); |
| up_write(&dentry->d_inode->i_alloc_sem); |
| mutex_unlock(&dentry->d_inode->i_mutex); |
| } else |
| update_ctime(inode); |
| out_unlock: |
| up_write(&REISERFS_I(inode)->i_xattr_sem); |
| dput(dentry); |
| return err; |
| } |
| |
| /* We need to start a transaction to maintain lock ordering */ |
| int reiserfs_xattr_set(struct inode *inode, const char *name, |
| const void *buffer, size_t buffer_size, int flags) |
| { |
| |
| struct reiserfs_transaction_handle th; |
| int error, error2; |
| size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size); |
| |
| if (!(flags & XATTR_REPLACE)) |
| jbegin_count += reiserfs_xattr_jcreate_nblocks(inode); |
| |
| reiserfs_write_lock(inode->i_sb); |
| error = journal_begin(&th, inode->i_sb, jbegin_count); |
| if (error) { |
| reiserfs_write_unlock(inode->i_sb); |
| return error; |
| } |
| |
| error = reiserfs_xattr_set_handle(&th, inode, name, |
| buffer, buffer_size, flags); |
| |
| error2 = journal_end(&th, inode->i_sb, jbegin_count); |
| if (error == 0) |
| error = error2; |
| reiserfs_write_unlock(inode->i_sb); |
| |
| return error; |
| } |
| |
| /* |
| * inode->i_mutex: down |
| */ |
| int |
| reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer, |
| size_t buffer_size) |
| { |
| ssize_t err = 0; |
| struct dentry *dentry; |
| size_t isize; |
| size_t file_pos = 0; |
| size_t buffer_pos = 0; |
| struct page *page; |
| __u32 hash = 0; |
| |
| if (name == NULL) |
| return -EINVAL; |
| |
| /* We can't have xattrs attached to v1 items since they don't have |
| * generation numbers */ |
| if (get_inode_sd_version(inode) == STAT_DATA_V1) |
| return -EOPNOTSUPP; |
| |
| dentry = xattr_lookup(inode, name, XATTR_REPLACE); |
| if (IS_ERR(dentry)) { |
| err = PTR_ERR(dentry); |
| goto out; |
| } |
| |
| down_read(&REISERFS_I(inode)->i_xattr_sem); |
| |
| isize = i_size_read(dentry->d_inode); |
| |
| /* Just return the size needed */ |
| if (buffer == NULL) { |
| err = isize - sizeof(struct reiserfs_xattr_header); |
| goto out_unlock; |
| } |
| |
| if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) { |
| err = -ERANGE; |
| goto out_unlock; |
| } |
| |
| while (file_pos < isize) { |
| size_t chunk; |
| char *data; |
| size_t skip = 0; |
| if (isize - file_pos > PAGE_CACHE_SIZE) |
| chunk = PAGE_CACHE_SIZE; |
| else |
| chunk = isize - file_pos; |
| |
| page = reiserfs_get_page(dentry->d_inode, file_pos); |
| if (IS_ERR(page)) { |
| err = PTR_ERR(page); |
| goto out_unlock; |
| } |
| |
| lock_page(page); |
| data = page_address(page); |
| if (file_pos == 0) { |
| struct reiserfs_xattr_header *rxh = |
| (struct reiserfs_xattr_header *)data; |
| skip = file_pos = sizeof(struct reiserfs_xattr_header); |
| chunk -= skip; |
| /* Magic doesn't match up.. */ |
| if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) { |
| unlock_page(page); |
| reiserfs_put_page(page); |
| reiserfs_warning(inode->i_sb, "jdm-20001", |
| "Invalid magic for xattr (%s) " |
| "associated with %k", name, |
| INODE_PKEY(inode)); |
| err = -EIO; |
| goto out_unlock; |
| } |
| hash = le32_to_cpu(rxh->h_hash); |
| } |
| memcpy(buffer + buffer_pos, data + skip, chunk); |
| unlock_page(page); |
| reiserfs_put_page(page); |
| file_pos += chunk; |
| buffer_pos += chunk; |
| skip = 0; |
| } |
| err = isize - sizeof(struct reiserfs_xattr_header); |
| |
| if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) != |
| hash) { |
| reiserfs_warning(inode->i_sb, "jdm-20002", |
| "Invalid hash for xattr (%s) associated " |
| "with %k", name, INODE_PKEY(inode)); |
| err = -EIO; |
| } |
| |
| out_unlock: |
| up_read(&REISERFS_I(inode)->i_xattr_sem); |
| dput(dentry); |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * In order to implement different sets of xattr operations for each xattr |
| * prefix with the generic xattr API, a filesystem should create a |
| * null-terminated array of struct xattr_handler (one for each prefix) and |
| * hang a pointer to it off of the s_xattr field of the superblock. |
| * |
| * The generic_fooxattr() functions will use this list to dispatch xattr |
| * operations to the correct xattr_handler. |
| */ |
| #define for_each_xattr_handler(handlers, handler) \ |
| for ((handler) = *(handlers)++; \ |
| (handler) != NULL; \ |
| (handler) = *(handlers)++) |
| |
| /* This is the implementation for the xattr plugin infrastructure */ |
| static inline const struct xattr_handler * |
| find_xattr_handler_prefix(const struct xattr_handler **handlers, |
| const char *name) |
| { |
| const struct xattr_handler *xah; |
| |
| if (!handlers) |
| return NULL; |
| |
| for_each_xattr_handler(handlers, xah) { |
| if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0) |
| break; |
| } |
| |
| return xah; |
| } |
| |
| |
| /* |
| * Inode operation getxattr() |
| */ |
| ssize_t |
| reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer, |
| size_t size) |
| { |
| const struct xattr_handler *handler; |
| |
| handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name); |
| |
| if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1) |
| return -EOPNOTSUPP; |
| |
| return handler->get(dentry, name, buffer, size, handler->flags); |
| } |
| |
| /* |
| * Inode operation setxattr() |
| * |
| * dentry->d_inode->i_mutex down |
| */ |
| int |
| reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value, |
| size_t size, int flags) |
| { |
| const struct xattr_handler *handler; |
| |
| handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name); |
| |
| if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1) |
| return -EOPNOTSUPP; |
| |
| return handler->set(dentry, name, value, size, flags, handler->flags); |
| } |
| |
| /* |
| * Inode operation removexattr() |
| * |
| * dentry->d_inode->i_mutex down |
| */ |
| int reiserfs_removexattr(struct dentry *dentry, const char *name) |
| { |
| const struct xattr_handler *handler; |
| handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name); |
| |
| if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1) |
| return -EOPNOTSUPP; |
| |
| return handler->set(dentry, name, NULL, 0, XATTR_REPLACE, handler->flags); |
| } |
| |
| struct listxattr_buf { |
| size_t size; |
| size_t pos; |
| char *buf; |
| struct dentry *dentry; |
| }; |
| |
| static int listxattr_filler(void *buf, const char *name, int namelen, |
| loff_t offset, u64 ino, unsigned int d_type) |
| { |
| struct listxattr_buf *b = (struct listxattr_buf *)buf; |
| size_t size; |
| if (name[0] != '.' || |
| (namelen != 1 && (name[1] != '.' || namelen != 2))) { |
| const struct xattr_handler *handler; |
| handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr, |
| name); |
| if (!handler) /* Unsupported xattr name */ |
| return 0; |
| if (b->buf) { |
| size = handler->list(b->dentry, b->buf + b->pos, |
| b->size, name, namelen, |
| handler->flags); |
| if (size > b->size) |
| return -ERANGE; |
| } else { |
| size = handler->list(b->dentry, NULL, 0, name, |
| namelen, handler->flags); |
| } |
| |
| b->pos += size; |
| } |
| return 0; |
| } |
| |
| /* |
| * Inode operation listxattr() |
| * |
| * We totally ignore the generic listxattr here because it would be stupid |
| * not to. Since the xattrs are organized in a directory, we can just |
| * readdir to find them. |
| */ |
| ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size) |
| { |
| struct dentry *dir; |
| int err = 0; |
| loff_t pos = 0; |
| struct listxattr_buf buf = { |
| .dentry = dentry, |
| .buf = buffer, |
| .size = buffer ? size : 0, |
| }; |
| |
| if (!dentry->d_inode) |
| return -EINVAL; |
| |
| if (!dentry->d_sb->s_xattr || |
| get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1) |
| return -EOPNOTSUPP; |
| |
| dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE); |
| if (IS_ERR(dir)) { |
| err = PTR_ERR(dir); |
| if (err == -ENODATA) |
| err = 0; /* Not an error if there aren't any xattrs */ |
| goto out; |
| } |
| |
| mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR); |
| err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos); |
| mutex_unlock(&dir->d_inode->i_mutex); |
| |
| if (!err) |
| err = buf.pos; |
| |
| dput(dir); |
| out: |
| return err; |
| } |
| |
| static int reiserfs_check_acl(struct inode *inode, int mask) |
| { |
| struct posix_acl *acl; |
| int error = -EAGAIN; /* do regular unix permission checks by default */ |
| |
| acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); |
| |
| if (acl) { |
| if (!IS_ERR(acl)) { |
| error = posix_acl_permission(inode, acl, mask); |
| posix_acl_release(acl); |
| } else if (PTR_ERR(acl) != -ENODATA) |
| error = PTR_ERR(acl); |
| } |
| |
| return error; |
| } |
| |
| static int create_privroot(struct dentry *dentry) |
| { |
| int err; |
| struct inode *inode = dentry->d_parent->d_inode; |
| WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex)); |
| |
| err = xattr_mkdir(inode, dentry, 0700); |
| if (err || !dentry->d_inode) { |
| reiserfs_warning(dentry->d_sb, "jdm-20006", |
| "xattrs/ACLs enabled and couldn't " |
| "find/create .reiserfs_priv. " |
| "Failing mount."); |
| return -EOPNOTSUPP; |
| } |
| |
| dentry->d_inode->i_flags |= S_PRIVATE; |
| reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr " |
| "storage.\n", PRIVROOT_NAME); |
| |
| return 0; |
| } |
| |
| #else |
| int __init reiserfs_xattr_register_handlers(void) { return 0; } |
| void reiserfs_xattr_unregister_handlers(void) {} |
| static int create_privroot(struct dentry *dentry) { return 0; } |
| #endif |
| |
| /* Actual operations that are exported to VFS-land */ |
| const struct xattr_handler *reiserfs_xattr_handlers[] = { |
| #ifdef CONFIG_REISERFS_FS_XATTR |
| &reiserfs_xattr_user_handler, |
| &reiserfs_xattr_trusted_handler, |
| #endif |
| #ifdef CONFIG_REISERFS_FS_SECURITY |
| &reiserfs_xattr_security_handler, |
| #endif |
| #ifdef CONFIG_REISERFS_FS_POSIX_ACL |
| &reiserfs_posix_acl_access_handler, |
| &reiserfs_posix_acl_default_handler, |
| #endif |
| NULL |
| }; |
| |
| static int xattr_mount_check(struct super_block *s) |
| { |
| /* We need generation numbers to ensure that the oid mapping is correct |
| * v3.5 filesystems don't have them. */ |
| if (old_format_only(s)) { |
| if (reiserfs_xattrs_optional(s)) { |
| /* Old format filesystem, but optional xattrs have |
| * been enabled. Error out. */ |
| reiserfs_warning(s, "jdm-2005", |
| "xattrs/ACLs not supported " |
| "on pre-v3.6 format filesystems. " |
| "Failing mount."); |
| return -EOPNOTSUPP; |
| } |
| } |
| |
| return 0; |
| } |
| |
| int reiserfs_permission(struct inode *inode, int mask) |
| { |
| /* |
| * We don't do permission checks on the internal objects. |
| * Permissions are determined by the "owning" object. |
| */ |
| if (IS_PRIVATE(inode)) |
| return 0; |
| |
| #ifdef CONFIG_REISERFS_FS_XATTR |
| /* |
| * Stat data v1 doesn't support ACLs. |
| */ |
| if (get_inode_sd_version(inode) != STAT_DATA_V1) |
| return generic_permission(inode, mask, reiserfs_check_acl); |
| #endif |
| return generic_permission(inode, mask, NULL); |
| } |
| |
| static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd) |
| { |
| return -EPERM; |
| } |
| |
| static const struct dentry_operations xattr_lookup_poison_ops = { |
| .d_revalidate = xattr_hide_revalidate, |
| }; |
| |
| int reiserfs_lookup_privroot(struct super_block *s) |
| { |
| struct dentry *dentry; |
| int err = 0; |
| |
| /* If we don't have the privroot located yet - go find it */ |
| reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s); |
| dentry = lookup_one_len(PRIVROOT_NAME, s->s_root, |
| strlen(PRIVROOT_NAME)); |
| if (!IS_ERR(dentry)) { |
| REISERFS_SB(s)->priv_root = dentry; |
| dentry->d_op = &xattr_lookup_poison_ops; |
| if (dentry->d_inode) |
| dentry->d_inode->i_flags |= S_PRIVATE; |
| } else |
| err = PTR_ERR(dentry); |
| mutex_unlock(&s->s_root->d_inode->i_mutex); |
| |
| return err; |
| } |
| |
| /* We need to take a copy of the mount flags since things like |
| * MS_RDONLY don't get set until *after* we're called. |
| * mount_flags != mount_options */ |
| int reiserfs_xattr_init(struct super_block *s, int mount_flags) |
| { |
| int err = 0; |
| struct dentry *privroot = REISERFS_SB(s)->priv_root; |
| |
| err = xattr_mount_check(s); |
| if (err) |
| goto error; |
| |
| if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) { |
| reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s); |
| err = create_privroot(REISERFS_SB(s)->priv_root); |
| mutex_unlock(&s->s_root->d_inode->i_mutex); |
| } |
| |
| if (privroot->d_inode) { |
| s->s_xattr = reiserfs_xattr_handlers; |
| reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s); |
| if (!REISERFS_SB(s)->xattr_root) { |
| struct dentry *dentry; |
| dentry = lookup_one_len(XAROOT_NAME, privroot, |
| strlen(XAROOT_NAME)); |
| if (!IS_ERR(dentry)) |
| REISERFS_SB(s)->xattr_root = dentry; |
| else |
| err = PTR_ERR(dentry); |
| } |
| mutex_unlock(&privroot->d_inode->i_mutex); |
| } |
| |
| error: |
| if (err) { |
| clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt)); |
| clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt)); |
| } |
| |
| /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */ |
| if (reiserfs_posixacl(s)) |
| s->s_flags |= MS_POSIXACL; |
| else |
| s->s_flags &= ~MS_POSIXACL; |
| |
| return err; |
| } |