11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * fs/libfs.c 31da177e4SLinus Torvalds * Library for filesystems writers. 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds #include <linux/module.h> 71da177e4SLinus Torvalds #include <linux/pagemap.h> 81da177e4SLinus Torvalds #include <linux/mount.h> 91da177e4SLinus Torvalds #include <linux/vfs.h> 107cf34c76SIngo Molnar #include <linux/mutex.h> 112596110aSChristoph Hellwig #include <linux/exportfs.h> 127cf34c76SIngo Molnar 131da177e4SLinus Torvalds #include <asm/uaccess.h> 141da177e4SLinus Torvalds 151da177e4SLinus Torvalds int simple_getattr(struct vfsmount *mnt, struct dentry *dentry, 161da177e4SLinus Torvalds struct kstat *stat) 171da177e4SLinus Torvalds { 181da177e4SLinus Torvalds struct inode *inode = dentry->d_inode; 191da177e4SLinus Torvalds generic_fillattr(inode, stat); 201da177e4SLinus Torvalds stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9); 211da177e4SLinus Torvalds return 0; 221da177e4SLinus Torvalds } 231da177e4SLinus Torvalds 24726c3342SDavid Howells int simple_statfs(struct dentry *dentry, struct kstatfs *buf) 251da177e4SLinus Torvalds { 26726c3342SDavid Howells buf->f_type = dentry->d_sb->s_magic; 271da177e4SLinus Torvalds buf->f_bsize = PAGE_CACHE_SIZE; 281da177e4SLinus Torvalds buf->f_namelen = NAME_MAX; 291da177e4SLinus Torvalds return 0; 301da177e4SLinus Torvalds } 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds /* 331da177e4SLinus Torvalds * Retaining negative dentries for an in-memory filesystem just wastes 341da177e4SLinus Torvalds * memory and lookup time: arrange for them to be deleted immediately. 351da177e4SLinus Torvalds */ 361da177e4SLinus Torvalds static int simple_delete_dentry(struct dentry *dentry) 371da177e4SLinus Torvalds { 381da177e4SLinus Torvalds return 1; 391da177e4SLinus Torvalds } 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds /* 421da177e4SLinus Torvalds * Lookup the data. This is trivial - if the dentry didn't already 431da177e4SLinus Torvalds * exist, we know it is negative. Set d_op to delete negative dentries. 441da177e4SLinus Torvalds */ 451da177e4SLinus Torvalds struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 461da177e4SLinus Torvalds { 471da177e4SLinus Torvalds static struct dentry_operations simple_dentry_operations = { 481da177e4SLinus Torvalds .d_delete = simple_delete_dentry, 491da177e4SLinus Torvalds }; 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds if (dentry->d_name.len > NAME_MAX) 521da177e4SLinus Torvalds return ERR_PTR(-ENAMETOOLONG); 531da177e4SLinus Torvalds dentry->d_op = &simple_dentry_operations; 541da177e4SLinus Torvalds d_add(dentry, NULL); 551da177e4SLinus Torvalds return NULL; 561da177e4SLinus Torvalds } 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds int simple_sync_file(struct file * file, struct dentry *dentry, int datasync) 591da177e4SLinus Torvalds { 601da177e4SLinus Torvalds return 0; 611da177e4SLinus Torvalds } 621da177e4SLinus Torvalds 631da177e4SLinus Torvalds int dcache_dir_open(struct inode *inode, struct file *file) 641da177e4SLinus Torvalds { 651da177e4SLinus Torvalds static struct qstr cursor_name = {.len = 1, .name = "."}; 661da177e4SLinus Torvalds 670f7fc9e4SJosef "Jeff" Sipek file->private_data = d_alloc(file->f_path.dentry, &cursor_name); 681da177e4SLinus Torvalds 691da177e4SLinus Torvalds return file->private_data ? 0 : -ENOMEM; 701da177e4SLinus Torvalds } 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds int dcache_dir_close(struct inode *inode, struct file *file) 731da177e4SLinus Torvalds { 741da177e4SLinus Torvalds dput(file->private_data); 751da177e4SLinus Torvalds return 0; 761da177e4SLinus Torvalds } 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) 791da177e4SLinus Torvalds { 800f7fc9e4SJosef "Jeff" Sipek mutex_lock(&file->f_path.dentry->d_inode->i_mutex); 811da177e4SLinus Torvalds switch (origin) { 821da177e4SLinus Torvalds case 1: 831da177e4SLinus Torvalds offset += file->f_pos; 841da177e4SLinus Torvalds case 0: 851da177e4SLinus Torvalds if (offset >= 0) 861da177e4SLinus Torvalds break; 871da177e4SLinus Torvalds default: 880f7fc9e4SJosef "Jeff" Sipek mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); 891da177e4SLinus Torvalds return -EINVAL; 901da177e4SLinus Torvalds } 911da177e4SLinus Torvalds if (offset != file->f_pos) { 921da177e4SLinus Torvalds file->f_pos = offset; 931da177e4SLinus Torvalds if (file->f_pos >= 2) { 941da177e4SLinus Torvalds struct list_head *p; 951da177e4SLinus Torvalds struct dentry *cursor = file->private_data; 961da177e4SLinus Torvalds loff_t n = file->f_pos - 2; 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds spin_lock(&dcache_lock); 995160ee6fSEric Dumazet list_del(&cursor->d_u.d_child); 1000f7fc9e4SJosef "Jeff" Sipek p = file->f_path.dentry->d_subdirs.next; 1010f7fc9e4SJosef "Jeff" Sipek while (n && p != &file->f_path.dentry->d_subdirs) { 1021da177e4SLinus Torvalds struct dentry *next; 1035160ee6fSEric Dumazet next = list_entry(p, struct dentry, d_u.d_child); 1041da177e4SLinus Torvalds if (!d_unhashed(next) && next->d_inode) 1051da177e4SLinus Torvalds n--; 1061da177e4SLinus Torvalds p = p->next; 1071da177e4SLinus Torvalds } 1085160ee6fSEric Dumazet list_add_tail(&cursor->d_u.d_child, p); 1091da177e4SLinus Torvalds spin_unlock(&dcache_lock); 1101da177e4SLinus Torvalds } 1111da177e4SLinus Torvalds } 1120f7fc9e4SJosef "Jeff" Sipek mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); 1131da177e4SLinus Torvalds return offset; 1141da177e4SLinus Torvalds } 1151da177e4SLinus Torvalds 1161da177e4SLinus Torvalds /* Relationship between i_mode and the DT_xxx types */ 1171da177e4SLinus Torvalds static inline unsigned char dt_type(struct inode *inode) 1181da177e4SLinus Torvalds { 1191da177e4SLinus Torvalds return (inode->i_mode >> 12) & 15; 1201da177e4SLinus Torvalds } 1211da177e4SLinus Torvalds 1221da177e4SLinus Torvalds /* 1231da177e4SLinus Torvalds * Directory is locked and all positive dentries in it are safe, since 1241da177e4SLinus Torvalds * for ramfs-type trees they can't go away without unlink() or rmdir(), 1251da177e4SLinus Torvalds * both impossible due to the lock on directory. 1261da177e4SLinus Torvalds */ 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) 1291da177e4SLinus Torvalds { 1300f7fc9e4SJosef "Jeff" Sipek struct dentry *dentry = filp->f_path.dentry; 1311da177e4SLinus Torvalds struct dentry *cursor = filp->private_data; 1325160ee6fSEric Dumazet struct list_head *p, *q = &cursor->d_u.d_child; 1331da177e4SLinus Torvalds ino_t ino; 1341da177e4SLinus Torvalds int i = filp->f_pos; 1351da177e4SLinus Torvalds 1361da177e4SLinus Torvalds switch (i) { 1371da177e4SLinus Torvalds case 0: 1381da177e4SLinus Torvalds ino = dentry->d_inode->i_ino; 1391da177e4SLinus Torvalds if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 1401da177e4SLinus Torvalds break; 1411da177e4SLinus Torvalds filp->f_pos++; 1421da177e4SLinus Torvalds i++; 1431da177e4SLinus Torvalds /* fallthrough */ 1441da177e4SLinus Torvalds case 1: 1451da177e4SLinus Torvalds ino = parent_ino(dentry); 1461da177e4SLinus Torvalds if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) 1471da177e4SLinus Torvalds break; 1481da177e4SLinus Torvalds filp->f_pos++; 1491da177e4SLinus Torvalds i++; 1501da177e4SLinus Torvalds /* fallthrough */ 1511da177e4SLinus Torvalds default: 1521da177e4SLinus Torvalds spin_lock(&dcache_lock); 1531bfba4e8SAkinobu Mita if (filp->f_pos == 2) 1541bfba4e8SAkinobu Mita list_move(q, &dentry->d_subdirs); 1551bfba4e8SAkinobu Mita 1561da177e4SLinus Torvalds for (p=q->next; p != &dentry->d_subdirs; p=p->next) { 1571da177e4SLinus Torvalds struct dentry *next; 1585160ee6fSEric Dumazet next = list_entry(p, struct dentry, d_u.d_child); 1591da177e4SLinus Torvalds if (d_unhashed(next) || !next->d_inode) 1601da177e4SLinus Torvalds continue; 1611da177e4SLinus Torvalds 1621da177e4SLinus Torvalds spin_unlock(&dcache_lock); 1630f8952c2SRonni Nielsen if (filldir(dirent, next->d_name.name, 1640f8952c2SRonni Nielsen next->d_name.len, filp->f_pos, 1650f8952c2SRonni Nielsen next->d_inode->i_ino, 1660f8952c2SRonni Nielsen dt_type(next->d_inode)) < 0) 1671da177e4SLinus Torvalds return 0; 1681da177e4SLinus Torvalds spin_lock(&dcache_lock); 1691da177e4SLinus Torvalds /* next is still alive */ 1701bfba4e8SAkinobu Mita list_move(q, p); 1711da177e4SLinus Torvalds p = q; 1721da177e4SLinus Torvalds filp->f_pos++; 1731da177e4SLinus Torvalds } 1741da177e4SLinus Torvalds spin_unlock(&dcache_lock); 1751da177e4SLinus Torvalds } 1761da177e4SLinus Torvalds return 0; 1771da177e4SLinus Torvalds } 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos) 1801da177e4SLinus Torvalds { 1811da177e4SLinus Torvalds return -EISDIR; 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds 1844b6f5d20SArjan van de Ven const struct file_operations simple_dir_operations = { 1851da177e4SLinus Torvalds .open = dcache_dir_open, 1861da177e4SLinus Torvalds .release = dcache_dir_close, 1871da177e4SLinus Torvalds .llseek = dcache_dir_lseek, 1881da177e4SLinus Torvalds .read = generic_read_dir, 1891da177e4SLinus Torvalds .readdir = dcache_readdir, 1908ae0b778SHugh Dickins .fsync = simple_sync_file, 1911da177e4SLinus Torvalds }; 1921da177e4SLinus Torvalds 19392e1d5beSArjan van de Ven const struct inode_operations simple_dir_inode_operations = { 1941da177e4SLinus Torvalds .lookup = simple_lookup, 1951da177e4SLinus Torvalds }; 1961da177e4SLinus Torvalds 197759b9775SHugh Dickins static const struct super_operations simple_super_operations = { 198759b9775SHugh Dickins .statfs = simple_statfs, 199759b9775SHugh Dickins }; 200759b9775SHugh Dickins 2011da177e4SLinus Torvalds /* 2021da177e4SLinus Torvalds * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that 2031da177e4SLinus Torvalds * will never be mountable) 2041da177e4SLinus Torvalds */ 205454e2398SDavid Howells int get_sb_pseudo(struct file_system_type *fs_type, char *name, 206ee9b6d61SJosef 'Jeff' Sipek const struct super_operations *ops, unsigned long magic, 207454e2398SDavid Howells struct vfsmount *mnt) 2081da177e4SLinus Torvalds { 2091da177e4SLinus Torvalds struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL); 2101da177e4SLinus Torvalds struct dentry *dentry; 2111da177e4SLinus Torvalds struct inode *root; 2121da177e4SLinus Torvalds struct qstr d_name = {.name = name, .len = strlen(name)}; 2131da177e4SLinus Torvalds 2141da177e4SLinus Torvalds if (IS_ERR(s)) 215454e2398SDavid Howells return PTR_ERR(s); 2161da177e4SLinus Torvalds 2171da177e4SLinus Torvalds s->s_flags = MS_NOUSER; 2181da177e4SLinus Torvalds s->s_maxbytes = ~0ULL; 2193971e1a9SAlex Nixon s->s_blocksize = PAGE_SIZE; 2203971e1a9SAlex Nixon s->s_blocksize_bits = PAGE_SHIFT; 2211da177e4SLinus Torvalds s->s_magic = magic; 222759b9775SHugh Dickins s->s_op = ops ? ops : &simple_super_operations; 2231da177e4SLinus Torvalds s->s_time_gran = 1; 2241da177e4SLinus Torvalds root = new_inode(s); 2251da177e4SLinus Torvalds if (!root) 2261da177e4SLinus Torvalds goto Enomem; 2271a1c9bb4SJeff Layton /* 2281a1c9bb4SJeff Layton * since this is the first inode, make it number 1. New inodes created 2291a1c9bb4SJeff Layton * after this must take care not to collide with it (by passing 2301a1c9bb4SJeff Layton * max_reserved of 1 to iunique). 2311a1c9bb4SJeff Layton */ 2321a1c9bb4SJeff Layton root->i_ino = 1; 2331da177e4SLinus Torvalds root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; 2341da177e4SLinus Torvalds root->i_uid = root->i_gid = 0; 2351da177e4SLinus Torvalds root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; 2361da177e4SLinus Torvalds dentry = d_alloc(NULL, &d_name); 2371da177e4SLinus Torvalds if (!dentry) { 2381da177e4SLinus Torvalds iput(root); 2391da177e4SLinus Torvalds goto Enomem; 2401da177e4SLinus Torvalds } 2411da177e4SLinus Torvalds dentry->d_sb = s; 2421da177e4SLinus Torvalds dentry->d_parent = dentry; 2431da177e4SLinus Torvalds d_instantiate(dentry, root); 2441da177e4SLinus Torvalds s->s_root = dentry; 2451da177e4SLinus Torvalds s->s_flags |= MS_ACTIVE; 246454e2398SDavid Howells return simple_set_mnt(mnt, s); 2471da177e4SLinus Torvalds 2481da177e4SLinus Torvalds Enomem: 2491da177e4SLinus Torvalds up_write(&s->s_umount); 2501da177e4SLinus Torvalds deactivate_super(s); 251454e2398SDavid Howells return -ENOMEM; 2521da177e4SLinus Torvalds } 2531da177e4SLinus Torvalds 2541da177e4SLinus Torvalds int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) 2551da177e4SLinus Torvalds { 2561da177e4SLinus Torvalds struct inode *inode = old_dentry->d_inode; 2571da177e4SLinus Torvalds 2581da177e4SLinus Torvalds inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; 259d8c76e6fSDave Hansen inc_nlink(inode); 2601da177e4SLinus Torvalds atomic_inc(&inode->i_count); 2611da177e4SLinus Torvalds dget(dentry); 2621da177e4SLinus Torvalds d_instantiate(dentry, inode); 2631da177e4SLinus Torvalds return 0; 2641da177e4SLinus Torvalds } 2651da177e4SLinus Torvalds 2661da177e4SLinus Torvalds static inline int simple_positive(struct dentry *dentry) 2671da177e4SLinus Torvalds { 2681da177e4SLinus Torvalds return dentry->d_inode && !d_unhashed(dentry); 2691da177e4SLinus Torvalds } 2701da177e4SLinus Torvalds 2711da177e4SLinus Torvalds int simple_empty(struct dentry *dentry) 2721da177e4SLinus Torvalds { 2731da177e4SLinus Torvalds struct dentry *child; 2741da177e4SLinus Torvalds int ret = 0; 2751da177e4SLinus Torvalds 2761da177e4SLinus Torvalds spin_lock(&dcache_lock); 2775160ee6fSEric Dumazet list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) 2781da177e4SLinus Torvalds if (simple_positive(child)) 2791da177e4SLinus Torvalds goto out; 2801da177e4SLinus Torvalds ret = 1; 2811da177e4SLinus Torvalds out: 2821da177e4SLinus Torvalds spin_unlock(&dcache_lock); 2831da177e4SLinus Torvalds return ret; 2841da177e4SLinus Torvalds } 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds int simple_unlink(struct inode *dir, struct dentry *dentry) 2871da177e4SLinus Torvalds { 2881da177e4SLinus Torvalds struct inode *inode = dentry->d_inode; 2891da177e4SLinus Torvalds 2901da177e4SLinus Torvalds inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; 2919a53c3a7SDave Hansen drop_nlink(inode); 2921da177e4SLinus Torvalds dput(dentry); 2931da177e4SLinus Torvalds return 0; 2941da177e4SLinus Torvalds } 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds int simple_rmdir(struct inode *dir, struct dentry *dentry) 2971da177e4SLinus Torvalds { 2981da177e4SLinus Torvalds if (!simple_empty(dentry)) 2991da177e4SLinus Torvalds return -ENOTEMPTY; 3001da177e4SLinus Torvalds 3019a53c3a7SDave Hansen drop_nlink(dentry->d_inode); 3021da177e4SLinus Torvalds simple_unlink(dir, dentry); 3039a53c3a7SDave Hansen drop_nlink(dir); 3041da177e4SLinus Torvalds return 0; 3051da177e4SLinus Torvalds } 3061da177e4SLinus Torvalds 3071da177e4SLinus Torvalds int simple_rename(struct inode *old_dir, struct dentry *old_dentry, 3081da177e4SLinus Torvalds struct inode *new_dir, struct dentry *new_dentry) 3091da177e4SLinus Torvalds { 3101da177e4SLinus Torvalds struct inode *inode = old_dentry->d_inode; 3111da177e4SLinus Torvalds int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode); 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds if (!simple_empty(new_dentry)) 3141da177e4SLinus Torvalds return -ENOTEMPTY; 3151da177e4SLinus Torvalds 3161da177e4SLinus Torvalds if (new_dentry->d_inode) { 3171da177e4SLinus Torvalds simple_unlink(new_dir, new_dentry); 3181da177e4SLinus Torvalds if (they_are_dirs) 3199a53c3a7SDave Hansen drop_nlink(old_dir); 3201da177e4SLinus Torvalds } else if (they_are_dirs) { 3219a53c3a7SDave Hansen drop_nlink(old_dir); 322d8c76e6fSDave Hansen inc_nlink(new_dir); 3231da177e4SLinus Torvalds } 3241da177e4SLinus Torvalds 3251da177e4SLinus Torvalds old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = 3261da177e4SLinus Torvalds new_dir->i_mtime = inode->i_ctime = CURRENT_TIME; 3271da177e4SLinus Torvalds 3281da177e4SLinus Torvalds return 0; 3291da177e4SLinus Torvalds } 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds int simple_readpage(struct file *file, struct page *page) 3321da177e4SLinus Torvalds { 333c0d92cbcSPekka J Enberg clear_highpage(page); 3341da177e4SLinus Torvalds flush_dcache_page(page); 3351da177e4SLinus Torvalds SetPageUptodate(page); 3361da177e4SLinus Torvalds unlock_page(page); 3371da177e4SLinus Torvalds return 0; 3381da177e4SLinus Torvalds } 3391da177e4SLinus Torvalds 3401da177e4SLinus Torvalds int simple_prepare_write(struct file *file, struct page *page, 3411da177e4SLinus Torvalds unsigned from, unsigned to) 3421da177e4SLinus Torvalds { 3431da177e4SLinus Torvalds if (!PageUptodate(page)) { 344eebd2aa3SChristoph Lameter if (to - from != PAGE_CACHE_SIZE) 345eebd2aa3SChristoph Lameter zero_user_segments(page, 346eebd2aa3SChristoph Lameter 0, from, 347eebd2aa3SChristoph Lameter to, PAGE_CACHE_SIZE); 3481da177e4SLinus Torvalds } 3491da177e4SLinus Torvalds return 0; 3501da177e4SLinus Torvalds } 3511da177e4SLinus Torvalds 352afddba49SNick Piggin int simple_write_begin(struct file *file, struct address_space *mapping, 353afddba49SNick Piggin loff_t pos, unsigned len, unsigned flags, 354afddba49SNick Piggin struct page **pagep, void **fsdata) 355afddba49SNick Piggin { 356afddba49SNick Piggin struct page *page; 357afddba49SNick Piggin pgoff_t index; 358afddba49SNick Piggin unsigned from; 359afddba49SNick Piggin 360afddba49SNick Piggin index = pos >> PAGE_CACHE_SHIFT; 361afddba49SNick Piggin from = pos & (PAGE_CACHE_SIZE - 1); 362afddba49SNick Piggin 363afddba49SNick Piggin page = __grab_cache_page(mapping, index); 364afddba49SNick Piggin if (!page) 365afddba49SNick Piggin return -ENOMEM; 366afddba49SNick Piggin 367afddba49SNick Piggin *pagep = page; 368afddba49SNick Piggin 369afddba49SNick Piggin return simple_prepare_write(file, page, from, from+len); 370afddba49SNick Piggin } 371afddba49SNick Piggin 3724a239427SAdrian Bunk static int simple_commit_write(struct file *file, struct page *page, 373955eff5aSNick Piggin unsigned from, unsigned to) 3741da177e4SLinus Torvalds { 3751da177e4SLinus Torvalds struct inode *inode = page->mapping->host; 3761da177e4SLinus Torvalds loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; 3771da177e4SLinus Torvalds 378955eff5aSNick Piggin if (!PageUptodate(page)) 379955eff5aSNick Piggin SetPageUptodate(page); 3801da177e4SLinus Torvalds /* 3811da177e4SLinus Torvalds * No need to use i_size_read() here, the i_size 3821b1dcc1bSJes Sorensen * cannot change under us because we hold the i_mutex. 3831da177e4SLinus Torvalds */ 3841da177e4SLinus Torvalds if (pos > inode->i_size) 3851da177e4SLinus Torvalds i_size_write(inode, pos); 3861da177e4SLinus Torvalds set_page_dirty(page); 3871da177e4SLinus Torvalds return 0; 3881da177e4SLinus Torvalds } 3891da177e4SLinus Torvalds 390afddba49SNick Piggin int simple_write_end(struct file *file, struct address_space *mapping, 391afddba49SNick Piggin loff_t pos, unsigned len, unsigned copied, 392afddba49SNick Piggin struct page *page, void *fsdata) 393afddba49SNick Piggin { 394afddba49SNick Piggin unsigned from = pos & (PAGE_CACHE_SIZE - 1); 395afddba49SNick Piggin 396afddba49SNick Piggin /* zero the stale part of the page if we did a short copy */ 397afddba49SNick Piggin if (copied < len) { 398afddba49SNick Piggin void *kaddr = kmap_atomic(page, KM_USER0); 399afddba49SNick Piggin memset(kaddr + from + copied, 0, len - copied); 400afddba49SNick Piggin flush_dcache_page(page); 401afddba49SNick Piggin kunmap_atomic(kaddr, KM_USER0); 402afddba49SNick Piggin } 403afddba49SNick Piggin 404afddba49SNick Piggin simple_commit_write(file, page, from, from+copied); 405afddba49SNick Piggin 406afddba49SNick Piggin unlock_page(page); 407afddba49SNick Piggin page_cache_release(page); 408afddba49SNick Piggin 409afddba49SNick Piggin return copied; 410afddba49SNick Piggin } 411afddba49SNick Piggin 4121a1c9bb4SJeff Layton /* 4131a1c9bb4SJeff Layton * the inodes created here are not hashed. If you use iunique to generate 4141a1c9bb4SJeff Layton * unique inode values later for this filesystem, then you must take care 4151a1c9bb4SJeff Layton * to pass it an appropriate max_reserved value to avoid collisions. 4161a1c9bb4SJeff Layton */ 4171da177e4SLinus Torvalds int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files) 4181da177e4SLinus Torvalds { 4191da177e4SLinus Torvalds struct inode *inode; 4201da177e4SLinus Torvalds struct dentry *root; 4211da177e4SLinus Torvalds struct dentry *dentry; 4221da177e4SLinus Torvalds int i; 4231da177e4SLinus Torvalds 4241da177e4SLinus Torvalds s->s_blocksize = PAGE_CACHE_SIZE; 4251da177e4SLinus Torvalds s->s_blocksize_bits = PAGE_CACHE_SHIFT; 4261da177e4SLinus Torvalds s->s_magic = magic; 427759b9775SHugh Dickins s->s_op = &simple_super_operations; 4281da177e4SLinus Torvalds s->s_time_gran = 1; 4291da177e4SLinus Torvalds 4301da177e4SLinus Torvalds inode = new_inode(s); 4311da177e4SLinus Torvalds if (!inode) 4321da177e4SLinus Torvalds return -ENOMEM; 4331a1c9bb4SJeff Layton /* 4341a1c9bb4SJeff Layton * because the root inode is 1, the files array must not contain an 4351a1c9bb4SJeff Layton * entry at index 1 4361a1c9bb4SJeff Layton */ 4371a1c9bb4SJeff Layton inode->i_ino = 1; 4381da177e4SLinus Torvalds inode->i_mode = S_IFDIR | 0755; 4391da177e4SLinus Torvalds inode->i_uid = inode->i_gid = 0; 4401da177e4SLinus Torvalds inode->i_blocks = 0; 4411da177e4SLinus Torvalds inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 4421da177e4SLinus Torvalds inode->i_op = &simple_dir_inode_operations; 4431da177e4SLinus Torvalds inode->i_fop = &simple_dir_operations; 4447656f328SVincent Hanquez inode->i_nlink = 2; 4451da177e4SLinus Torvalds root = d_alloc_root(inode); 4461da177e4SLinus Torvalds if (!root) { 4471da177e4SLinus Torvalds iput(inode); 4481da177e4SLinus Torvalds return -ENOMEM; 4491da177e4SLinus Torvalds } 4501da177e4SLinus Torvalds for (i = 0; !files->name || files->name[0]; i++, files++) { 4511da177e4SLinus Torvalds if (!files->name) 4521da177e4SLinus Torvalds continue; 4531a1c9bb4SJeff Layton 4541a1c9bb4SJeff Layton /* warn if it tries to conflict with the root inode */ 4551a1c9bb4SJeff Layton if (unlikely(i == 1)) 4561a1c9bb4SJeff Layton printk(KERN_WARNING "%s: %s passed in a files array" 4571a1c9bb4SJeff Layton "with an index of 1!\n", __func__, 4581a1c9bb4SJeff Layton s->s_type->name); 4591a1c9bb4SJeff Layton 4601da177e4SLinus Torvalds dentry = d_alloc_name(root, files->name); 4611da177e4SLinus Torvalds if (!dentry) 4621da177e4SLinus Torvalds goto out; 4631da177e4SLinus Torvalds inode = new_inode(s); 4641da177e4SLinus Torvalds if (!inode) 4651da177e4SLinus Torvalds goto out; 4661da177e4SLinus Torvalds inode->i_mode = S_IFREG | files->mode; 4671da177e4SLinus Torvalds inode->i_uid = inode->i_gid = 0; 4681da177e4SLinus Torvalds inode->i_blocks = 0; 4691da177e4SLinus Torvalds inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 4701da177e4SLinus Torvalds inode->i_fop = files->ops; 4711da177e4SLinus Torvalds inode->i_ino = i; 4721da177e4SLinus Torvalds d_add(dentry, inode); 4731da177e4SLinus Torvalds } 4741da177e4SLinus Torvalds s->s_root = root; 4751da177e4SLinus Torvalds return 0; 4761da177e4SLinus Torvalds out: 4771da177e4SLinus Torvalds d_genocide(root); 4781da177e4SLinus Torvalds dput(root); 4791da177e4SLinus Torvalds return -ENOMEM; 4801da177e4SLinus Torvalds } 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds static DEFINE_SPINLOCK(pin_fs_lock); 4831da177e4SLinus Torvalds 4841f5ce9e9STrond Myklebust int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count) 4851da177e4SLinus Torvalds { 4861da177e4SLinus Torvalds struct vfsmount *mnt = NULL; 4871da177e4SLinus Torvalds spin_lock(&pin_fs_lock); 4881da177e4SLinus Torvalds if (unlikely(!*mount)) { 4891da177e4SLinus Torvalds spin_unlock(&pin_fs_lock); 4901f5ce9e9STrond Myklebust mnt = vfs_kern_mount(type, 0, type->name, NULL); 4911da177e4SLinus Torvalds if (IS_ERR(mnt)) 4921da177e4SLinus Torvalds return PTR_ERR(mnt); 4931da177e4SLinus Torvalds spin_lock(&pin_fs_lock); 4941da177e4SLinus Torvalds if (!*mount) 4951da177e4SLinus Torvalds *mount = mnt; 4961da177e4SLinus Torvalds } 4971da177e4SLinus Torvalds mntget(*mount); 4981da177e4SLinus Torvalds ++*count; 4991da177e4SLinus Torvalds spin_unlock(&pin_fs_lock); 5001da177e4SLinus Torvalds mntput(mnt); 5011da177e4SLinus Torvalds return 0; 5021da177e4SLinus Torvalds } 5031da177e4SLinus Torvalds 5041da177e4SLinus Torvalds void simple_release_fs(struct vfsmount **mount, int *count) 5051da177e4SLinus Torvalds { 5061da177e4SLinus Torvalds struct vfsmount *mnt; 5071da177e4SLinus Torvalds spin_lock(&pin_fs_lock); 5081da177e4SLinus Torvalds mnt = *mount; 5091da177e4SLinus Torvalds if (!--*count) 5101da177e4SLinus Torvalds *mount = NULL; 5111da177e4SLinus Torvalds spin_unlock(&pin_fs_lock); 5121da177e4SLinus Torvalds mntput(mnt); 5131da177e4SLinus Torvalds } 5141da177e4SLinus Torvalds 5156d1029b5SAkinobu Mita /** 5166d1029b5SAkinobu Mita * simple_read_from_buffer - copy data from the buffer to user space 5176d1029b5SAkinobu Mita * @to: the user space buffer to read to 5186d1029b5SAkinobu Mita * @count: the maximum number of bytes to read 5196d1029b5SAkinobu Mita * @ppos: the current position in the buffer 5206d1029b5SAkinobu Mita * @from: the buffer to read from 5216d1029b5SAkinobu Mita * @available: the size of the buffer 5226d1029b5SAkinobu Mita * 5236d1029b5SAkinobu Mita * The simple_read_from_buffer() function reads up to @count bytes from the 5246d1029b5SAkinobu Mita * buffer @from at offset @ppos into the user space address starting at @to. 5256d1029b5SAkinobu Mita * 5266d1029b5SAkinobu Mita * On success, the number of bytes read is returned and the offset @ppos is 5276d1029b5SAkinobu Mita * advanced by this number, or negative value is returned on error. 5286d1029b5SAkinobu Mita **/ 5291da177e4SLinus Torvalds ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, 5301da177e4SLinus Torvalds const void *from, size_t available) 5311da177e4SLinus Torvalds { 5321da177e4SLinus Torvalds loff_t pos = *ppos; 5331da177e4SLinus Torvalds if (pos < 0) 5341da177e4SLinus Torvalds return -EINVAL; 5351da177e4SLinus Torvalds if (pos >= available) 5361da177e4SLinus Torvalds return 0; 5371da177e4SLinus Torvalds if (count > available - pos) 5381da177e4SLinus Torvalds count = available - pos; 5391da177e4SLinus Torvalds if (copy_to_user(to, from + pos, count)) 5401da177e4SLinus Torvalds return -EFAULT; 5411da177e4SLinus Torvalds *ppos = pos + count; 5421da177e4SLinus Torvalds return count; 5431da177e4SLinus Torvalds } 5441da177e4SLinus Torvalds 5456d1029b5SAkinobu Mita /** 5466d1029b5SAkinobu Mita * memory_read_from_buffer - copy data from the buffer 5476d1029b5SAkinobu Mita * @to: the kernel space buffer to read to 5486d1029b5SAkinobu Mita * @count: the maximum number of bytes to read 5496d1029b5SAkinobu Mita * @ppos: the current position in the buffer 5506d1029b5SAkinobu Mita * @from: the buffer to read from 5516d1029b5SAkinobu Mita * @available: the size of the buffer 5526d1029b5SAkinobu Mita * 5536d1029b5SAkinobu Mita * The memory_read_from_buffer() function reads up to @count bytes from the 5546d1029b5SAkinobu Mita * buffer @from at offset @ppos into the kernel space address starting at @to. 5556d1029b5SAkinobu Mita * 5566d1029b5SAkinobu Mita * On success, the number of bytes read is returned and the offset @ppos is 5576d1029b5SAkinobu Mita * advanced by this number, or negative value is returned on error. 5586d1029b5SAkinobu Mita **/ 55993b07113SAkinobu Mita ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 56093b07113SAkinobu Mita const void *from, size_t available) 56193b07113SAkinobu Mita { 56293b07113SAkinobu Mita loff_t pos = *ppos; 56393b07113SAkinobu Mita 56493b07113SAkinobu Mita if (pos < 0) 56593b07113SAkinobu Mita return -EINVAL; 56693b07113SAkinobu Mita if (pos >= available) 56793b07113SAkinobu Mita return 0; 56893b07113SAkinobu Mita if (count > available - pos) 56993b07113SAkinobu Mita count = available - pos; 57093b07113SAkinobu Mita memcpy(to, from + pos, count); 57193b07113SAkinobu Mita *ppos = pos + count; 57293b07113SAkinobu Mita 57393b07113SAkinobu Mita return count; 57493b07113SAkinobu Mita } 57593b07113SAkinobu Mita 5761da177e4SLinus Torvalds /* 5771da177e4SLinus Torvalds * Transaction based IO. 5781da177e4SLinus Torvalds * The file expects a single write which triggers the transaction, and then 5791da177e4SLinus Torvalds * possibly a read which collects the result - which is stored in a 5801da177e4SLinus Torvalds * file-local buffer. 5811da177e4SLinus Torvalds */ 5821da177e4SLinus Torvalds char *simple_transaction_get(struct file *file, const char __user *buf, size_t size) 5831da177e4SLinus Torvalds { 5841da177e4SLinus Torvalds struct simple_transaction_argresp *ar; 5851da177e4SLinus Torvalds static DEFINE_SPINLOCK(simple_transaction_lock); 5861da177e4SLinus Torvalds 5871da177e4SLinus Torvalds if (size > SIMPLE_TRANSACTION_LIMIT - 1) 5881da177e4SLinus Torvalds return ERR_PTR(-EFBIG); 5891da177e4SLinus Torvalds 5901da177e4SLinus Torvalds ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL); 5911da177e4SLinus Torvalds if (!ar) 5921da177e4SLinus Torvalds return ERR_PTR(-ENOMEM); 5931da177e4SLinus Torvalds 5941da177e4SLinus Torvalds spin_lock(&simple_transaction_lock); 5951da177e4SLinus Torvalds 5961da177e4SLinus Torvalds /* only one write allowed per open */ 5971da177e4SLinus Torvalds if (file->private_data) { 5981da177e4SLinus Torvalds spin_unlock(&simple_transaction_lock); 5991da177e4SLinus Torvalds free_page((unsigned long)ar); 6001da177e4SLinus Torvalds return ERR_PTR(-EBUSY); 6011da177e4SLinus Torvalds } 6021da177e4SLinus Torvalds 6031da177e4SLinus Torvalds file->private_data = ar; 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds spin_unlock(&simple_transaction_lock); 6061da177e4SLinus Torvalds 6071da177e4SLinus Torvalds if (copy_from_user(ar->data, buf, size)) 6081da177e4SLinus Torvalds return ERR_PTR(-EFAULT); 6091da177e4SLinus Torvalds 6101da177e4SLinus Torvalds return ar->data; 6111da177e4SLinus Torvalds } 6121da177e4SLinus Torvalds 6131da177e4SLinus Torvalds ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos) 6141da177e4SLinus Torvalds { 6151da177e4SLinus Torvalds struct simple_transaction_argresp *ar = file->private_data; 6161da177e4SLinus Torvalds 6171da177e4SLinus Torvalds if (!ar) 6181da177e4SLinus Torvalds return 0; 6191da177e4SLinus Torvalds return simple_read_from_buffer(buf, size, pos, ar->data, ar->size); 6201da177e4SLinus Torvalds } 6211da177e4SLinus Torvalds 6221da177e4SLinus Torvalds int simple_transaction_release(struct inode *inode, struct file *file) 6231da177e4SLinus Torvalds { 6241da177e4SLinus Torvalds free_page((unsigned long)file->private_data); 6251da177e4SLinus Torvalds return 0; 6261da177e4SLinus Torvalds } 6271da177e4SLinus Torvalds 628acaefc25SArnd Bergmann /* Simple attribute files */ 629acaefc25SArnd Bergmann 630acaefc25SArnd Bergmann struct simple_attr { 6318b88b099SChristoph Hellwig int (*get)(void *, u64 *); 6328b88b099SChristoph Hellwig int (*set)(void *, u64); 633acaefc25SArnd Bergmann char get_buf[24]; /* enough to store a u64 and "\n\0" */ 634acaefc25SArnd Bergmann char set_buf[24]; 635acaefc25SArnd Bergmann void *data; 636acaefc25SArnd Bergmann const char *fmt; /* format for read operation */ 6377cf34c76SIngo Molnar struct mutex mutex; /* protects access to these buffers */ 638acaefc25SArnd Bergmann }; 639acaefc25SArnd Bergmann 640acaefc25SArnd Bergmann /* simple_attr_open is called by an actual attribute open file operation 641acaefc25SArnd Bergmann * to set the attribute specific access operations. */ 642acaefc25SArnd Bergmann int simple_attr_open(struct inode *inode, struct file *file, 6438b88b099SChristoph Hellwig int (*get)(void *, u64 *), int (*set)(void *, u64), 644acaefc25SArnd Bergmann const char *fmt) 645acaefc25SArnd Bergmann { 646acaefc25SArnd Bergmann struct simple_attr *attr; 647acaefc25SArnd Bergmann 648acaefc25SArnd Bergmann attr = kmalloc(sizeof(*attr), GFP_KERNEL); 649acaefc25SArnd Bergmann if (!attr) 650acaefc25SArnd Bergmann return -ENOMEM; 651acaefc25SArnd Bergmann 652acaefc25SArnd Bergmann attr->get = get; 653acaefc25SArnd Bergmann attr->set = set; 6548e18e294STheodore Ts'o attr->data = inode->i_private; 655acaefc25SArnd Bergmann attr->fmt = fmt; 6567cf34c76SIngo Molnar mutex_init(&attr->mutex); 657acaefc25SArnd Bergmann 658acaefc25SArnd Bergmann file->private_data = attr; 659acaefc25SArnd Bergmann 660acaefc25SArnd Bergmann return nonseekable_open(inode, file); 661acaefc25SArnd Bergmann } 662acaefc25SArnd Bergmann 66374bedc4dSChristoph Hellwig int simple_attr_release(struct inode *inode, struct file *file) 664acaefc25SArnd Bergmann { 665acaefc25SArnd Bergmann kfree(file->private_data); 666acaefc25SArnd Bergmann return 0; 667acaefc25SArnd Bergmann } 668acaefc25SArnd Bergmann 669acaefc25SArnd Bergmann /* read from the buffer that is filled with the get function */ 670acaefc25SArnd Bergmann ssize_t simple_attr_read(struct file *file, char __user *buf, 671acaefc25SArnd Bergmann size_t len, loff_t *ppos) 672acaefc25SArnd Bergmann { 673acaefc25SArnd Bergmann struct simple_attr *attr; 674acaefc25SArnd Bergmann size_t size; 675acaefc25SArnd Bergmann ssize_t ret; 676acaefc25SArnd Bergmann 677acaefc25SArnd Bergmann attr = file->private_data; 678acaefc25SArnd Bergmann 679acaefc25SArnd Bergmann if (!attr->get) 680acaefc25SArnd Bergmann return -EACCES; 681acaefc25SArnd Bergmann 6829261303aSChristoph Hellwig ret = mutex_lock_interruptible(&attr->mutex); 6839261303aSChristoph Hellwig if (ret) 6849261303aSChristoph Hellwig return ret; 6859261303aSChristoph Hellwig 6868b88b099SChristoph Hellwig if (*ppos) { /* continued read */ 687acaefc25SArnd Bergmann size = strlen(attr->get_buf); 6888b88b099SChristoph Hellwig } else { /* first read */ 6898b88b099SChristoph Hellwig u64 val; 6908b88b099SChristoph Hellwig ret = attr->get(attr->data, &val); 6918b88b099SChristoph Hellwig if (ret) 6928b88b099SChristoph Hellwig goto out; 6938b88b099SChristoph Hellwig 694acaefc25SArnd Bergmann size = scnprintf(attr->get_buf, sizeof(attr->get_buf), 6958b88b099SChristoph Hellwig attr->fmt, (unsigned long long)val); 6968b88b099SChristoph Hellwig } 697acaefc25SArnd Bergmann 698acaefc25SArnd Bergmann ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size); 6998b88b099SChristoph Hellwig out: 7007cf34c76SIngo Molnar mutex_unlock(&attr->mutex); 701acaefc25SArnd Bergmann return ret; 702acaefc25SArnd Bergmann } 703acaefc25SArnd Bergmann 704acaefc25SArnd Bergmann /* interpret the buffer as a number to call the set function with */ 705acaefc25SArnd Bergmann ssize_t simple_attr_write(struct file *file, const char __user *buf, 706acaefc25SArnd Bergmann size_t len, loff_t *ppos) 707acaefc25SArnd Bergmann { 708acaefc25SArnd Bergmann struct simple_attr *attr; 709acaefc25SArnd Bergmann u64 val; 710acaefc25SArnd Bergmann size_t size; 711acaefc25SArnd Bergmann ssize_t ret; 712acaefc25SArnd Bergmann 713acaefc25SArnd Bergmann attr = file->private_data; 714acaefc25SArnd Bergmann if (!attr->set) 715acaefc25SArnd Bergmann return -EACCES; 716acaefc25SArnd Bergmann 7179261303aSChristoph Hellwig ret = mutex_lock_interruptible(&attr->mutex); 7189261303aSChristoph Hellwig if (ret) 7199261303aSChristoph Hellwig return ret; 7209261303aSChristoph Hellwig 721acaefc25SArnd Bergmann ret = -EFAULT; 722acaefc25SArnd Bergmann size = min(sizeof(attr->set_buf) - 1, len); 723acaefc25SArnd Bergmann if (copy_from_user(attr->set_buf, buf, size)) 724acaefc25SArnd Bergmann goto out; 725acaefc25SArnd Bergmann 726acaefc25SArnd Bergmann ret = len; /* claim we got the whole input */ 727acaefc25SArnd Bergmann attr->set_buf[size] = '\0'; 728acaefc25SArnd Bergmann val = simple_strtol(attr->set_buf, NULL, 0); 729acaefc25SArnd Bergmann attr->set(attr->data, val); 730acaefc25SArnd Bergmann out: 7317cf34c76SIngo Molnar mutex_unlock(&attr->mutex); 732acaefc25SArnd Bergmann return ret; 733acaefc25SArnd Bergmann } 734acaefc25SArnd Bergmann 7352596110aSChristoph Hellwig /* 7362596110aSChristoph Hellwig * This is what d_alloc_anon should have been. Once the exportfs 7372596110aSChristoph Hellwig * argument transition has been finished I will update d_alloc_anon 7382596110aSChristoph Hellwig * to this prototype and this wrapper will go away. --hch 7392596110aSChristoph Hellwig */ 7402596110aSChristoph Hellwig static struct dentry *exportfs_d_alloc(struct inode *inode) 7412596110aSChristoph Hellwig { 7422596110aSChristoph Hellwig struct dentry *dentry; 7432596110aSChristoph Hellwig 7442596110aSChristoph Hellwig if (!inode) 7452596110aSChristoph Hellwig return NULL; 7462596110aSChristoph Hellwig if (IS_ERR(inode)) 7472596110aSChristoph Hellwig return ERR_PTR(PTR_ERR(inode)); 7482596110aSChristoph Hellwig 7492596110aSChristoph Hellwig dentry = d_alloc_anon(inode); 7502596110aSChristoph Hellwig if (!dentry) { 7512596110aSChristoph Hellwig iput(inode); 7522596110aSChristoph Hellwig dentry = ERR_PTR(-ENOMEM); 7532596110aSChristoph Hellwig } 7542596110aSChristoph Hellwig return dentry; 7552596110aSChristoph Hellwig } 7562596110aSChristoph Hellwig 7572596110aSChristoph Hellwig /** 7582596110aSChristoph Hellwig * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation 7592596110aSChristoph Hellwig * @sb: filesystem to do the file handle conversion on 7602596110aSChristoph Hellwig * @fid: file handle to convert 7612596110aSChristoph Hellwig * @fh_len: length of the file handle in bytes 7622596110aSChristoph Hellwig * @fh_type: type of file handle 7632596110aSChristoph Hellwig * @get_inode: filesystem callback to retrieve inode 7642596110aSChristoph Hellwig * 7652596110aSChristoph Hellwig * This function decodes @fid as long as it has one of the well-known 7662596110aSChristoph Hellwig * Linux filehandle types and calls @get_inode on it to retrieve the 7672596110aSChristoph Hellwig * inode for the object specified in the file handle. 7682596110aSChristoph Hellwig */ 7692596110aSChristoph Hellwig struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid, 7702596110aSChristoph Hellwig int fh_len, int fh_type, struct inode *(*get_inode) 7712596110aSChristoph Hellwig (struct super_block *sb, u64 ino, u32 gen)) 7722596110aSChristoph Hellwig { 7732596110aSChristoph Hellwig struct inode *inode = NULL; 7742596110aSChristoph Hellwig 7752596110aSChristoph Hellwig if (fh_len < 2) 7762596110aSChristoph Hellwig return NULL; 7772596110aSChristoph Hellwig 7782596110aSChristoph Hellwig switch (fh_type) { 7792596110aSChristoph Hellwig case FILEID_INO32_GEN: 7802596110aSChristoph Hellwig case FILEID_INO32_GEN_PARENT: 7812596110aSChristoph Hellwig inode = get_inode(sb, fid->i32.ino, fid->i32.gen); 7822596110aSChristoph Hellwig break; 7832596110aSChristoph Hellwig } 7842596110aSChristoph Hellwig 7852596110aSChristoph Hellwig return exportfs_d_alloc(inode); 7862596110aSChristoph Hellwig } 7872596110aSChristoph Hellwig EXPORT_SYMBOL_GPL(generic_fh_to_dentry); 7882596110aSChristoph Hellwig 7892596110aSChristoph Hellwig /** 7902596110aSChristoph Hellwig * generic_fh_to_dentry - generic helper for the fh_to_parent export operation 7912596110aSChristoph Hellwig * @sb: filesystem to do the file handle conversion on 7922596110aSChristoph Hellwig * @fid: file handle to convert 7932596110aSChristoph Hellwig * @fh_len: length of the file handle in bytes 7942596110aSChristoph Hellwig * @fh_type: type of file handle 7952596110aSChristoph Hellwig * @get_inode: filesystem callback to retrieve inode 7962596110aSChristoph Hellwig * 7972596110aSChristoph Hellwig * This function decodes @fid as long as it has one of the well-known 7982596110aSChristoph Hellwig * Linux filehandle types and calls @get_inode on it to retrieve the 7992596110aSChristoph Hellwig * inode for the _parent_ object specified in the file handle if it 8002596110aSChristoph Hellwig * is specified in the file handle, or NULL otherwise. 8012596110aSChristoph Hellwig */ 8022596110aSChristoph Hellwig struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid, 8032596110aSChristoph Hellwig int fh_len, int fh_type, struct inode *(*get_inode) 8042596110aSChristoph Hellwig (struct super_block *sb, u64 ino, u32 gen)) 8052596110aSChristoph Hellwig { 8062596110aSChristoph Hellwig struct inode *inode = NULL; 8072596110aSChristoph Hellwig 8082596110aSChristoph Hellwig if (fh_len <= 2) 8092596110aSChristoph Hellwig return NULL; 8102596110aSChristoph Hellwig 8112596110aSChristoph Hellwig switch (fh_type) { 8122596110aSChristoph Hellwig case FILEID_INO32_GEN_PARENT: 8132596110aSChristoph Hellwig inode = get_inode(sb, fid->i32.parent_ino, 8142596110aSChristoph Hellwig (fh_len > 3 ? fid->i32.parent_gen : 0)); 8152596110aSChristoph Hellwig break; 8162596110aSChristoph Hellwig } 8172596110aSChristoph Hellwig 8182596110aSChristoph Hellwig return exportfs_d_alloc(inode); 8192596110aSChristoph Hellwig } 8202596110aSChristoph Hellwig EXPORT_SYMBOL_GPL(generic_fh_to_parent); 8212596110aSChristoph Hellwig 8221da177e4SLinus Torvalds EXPORT_SYMBOL(dcache_dir_close); 8231da177e4SLinus Torvalds EXPORT_SYMBOL(dcache_dir_lseek); 8241da177e4SLinus Torvalds EXPORT_SYMBOL(dcache_dir_open); 8251da177e4SLinus Torvalds EXPORT_SYMBOL(dcache_readdir); 8261da177e4SLinus Torvalds EXPORT_SYMBOL(generic_read_dir); 8271da177e4SLinus Torvalds EXPORT_SYMBOL(get_sb_pseudo); 828afddba49SNick Piggin EXPORT_SYMBOL(simple_write_begin); 829afddba49SNick Piggin EXPORT_SYMBOL(simple_write_end); 8301da177e4SLinus Torvalds EXPORT_SYMBOL(simple_dir_inode_operations); 8311da177e4SLinus Torvalds EXPORT_SYMBOL(simple_dir_operations); 8321da177e4SLinus Torvalds EXPORT_SYMBOL(simple_empty); 8331da177e4SLinus Torvalds EXPORT_SYMBOL(d_alloc_name); 8341da177e4SLinus Torvalds EXPORT_SYMBOL(simple_fill_super); 8351da177e4SLinus Torvalds EXPORT_SYMBOL(simple_getattr); 8361da177e4SLinus Torvalds EXPORT_SYMBOL(simple_link); 8371da177e4SLinus Torvalds EXPORT_SYMBOL(simple_lookup); 8381da177e4SLinus Torvalds EXPORT_SYMBOL(simple_pin_fs); 8391da177e4SLinus Torvalds EXPORT_SYMBOL(simple_prepare_write); 8401da177e4SLinus Torvalds EXPORT_SYMBOL(simple_readpage); 8411da177e4SLinus Torvalds EXPORT_SYMBOL(simple_release_fs); 8421da177e4SLinus Torvalds EXPORT_SYMBOL(simple_rename); 8431da177e4SLinus Torvalds EXPORT_SYMBOL(simple_rmdir); 8441da177e4SLinus Torvalds EXPORT_SYMBOL(simple_statfs); 8451da177e4SLinus Torvalds EXPORT_SYMBOL(simple_sync_file); 8461da177e4SLinus Torvalds EXPORT_SYMBOL(simple_unlink); 8471da177e4SLinus Torvalds EXPORT_SYMBOL(simple_read_from_buffer); 84893b07113SAkinobu Mita EXPORT_SYMBOL(memory_read_from_buffer); 8491da177e4SLinus Torvalds EXPORT_SYMBOL(simple_transaction_get); 8501da177e4SLinus Torvalds EXPORT_SYMBOL(simple_transaction_read); 8511da177e4SLinus Torvalds EXPORT_SYMBOL(simple_transaction_release); 852acaefc25SArnd Bergmann EXPORT_SYMBOL_GPL(simple_attr_open); 85374bedc4dSChristoph Hellwig EXPORT_SYMBOL_GPL(simple_attr_release); 854acaefc25SArnd Bergmann EXPORT_SYMBOL_GPL(simple_attr_read); 855acaefc25SArnd Bergmann EXPORT_SYMBOL_GPL(simple_attr_write); 856