X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Flibfs.c;h=6e8d17e1dc4c95db609308d2ef59c8e314be79fe;hb=f958a1320ff7a1e0e861d3c90de6da12a88839dc;hp=fc785d8befb95faa14e424bb5ab0853109344a10;hpb=816724e65c72a90a44fbad0ef0b59b186c85fa90;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/libfs.c b/fs/libfs.c index fc785d8..6e8d17e 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -8,6 +8,9 @@ #include #include #include +#include +#include +#include #include @@ -43,7 +46,7 @@ static int simple_delete_dentry(struct dentry *dentry) */ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { - static struct dentry_operations simple_dentry_operations = { + static const struct dentry_operations simple_dentry_operations = { .d_delete = simple_delete_dentry, }; @@ -63,7 +66,7 @@ int dcache_dir_open(struct inode *inode, struct file *file) { static struct qstr cursor_name = {.len = 1, .name = "."}; - file->private_data = d_alloc(file->f_dentry, &cursor_name); + file->private_data = d_alloc(file->f_path.dentry, &cursor_name); return file->private_data ? 0 : -ENOMEM; } @@ -76,7 +79,7 @@ int dcache_dir_close(struct inode *inode, struct file *file) loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) { - mutex_lock(&file->f_dentry->d_inode->i_mutex); + mutex_lock(&file->f_path.dentry->d_inode->i_mutex); switch (origin) { case 1: offset += file->f_pos; @@ -84,7 +87,7 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) if (offset >= 0) break; default: - mutex_unlock(&file->f_dentry->d_inode->i_mutex); + mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); return -EINVAL; } if (offset != file->f_pos) { @@ -96,8 +99,8 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) spin_lock(&dcache_lock); list_del(&cursor->d_u.d_child); - p = file->f_dentry->d_subdirs.next; - while (n && p != &file->f_dentry->d_subdirs) { + p = file->f_path.dentry->d_subdirs.next; + while (n && p != &file->f_path.dentry->d_subdirs) { struct dentry *next; next = list_entry(p, struct dentry, d_u.d_child); if (!d_unhashed(next) && next->d_inode) @@ -108,7 +111,7 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) spin_unlock(&dcache_lock); } } - mutex_unlock(&file->f_dentry->d_inode->i_mutex); + mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); return offset; } @@ -126,7 +129,7 @@ static inline unsigned char dt_type(struct inode *inode) int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) { - struct dentry *dentry = filp->f_dentry; + struct dentry *dentry = filp->f_path.dentry; struct dentry *cursor = filp->private_data; struct list_head *p, *q = &cursor->d_u.d_child; ino_t ino; @@ -149,10 +152,9 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) /* fallthrough */ default: spin_lock(&dcache_lock); - if (filp->f_pos == 2) { - list_del(q); - list_add(q, &dentry->d_subdirs); - } + if (filp->f_pos == 2) + list_move(q, &dentry->d_subdirs); + for (p=q->next; p != &dentry->d_subdirs; p=p->next) { struct dentry *next; next = list_entry(p, struct dentry, d_u.d_child); @@ -160,12 +162,14 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) continue; spin_unlock(&dcache_lock); - if (filldir(dirent, next->d_name.name, next->d_name.len, filp->f_pos, next->d_inode->i_ino, dt_type(next->d_inode)) < 0) + if (filldir(dirent, next->d_name.name, + next->d_name.len, filp->f_pos, + next->d_inode->i_ino, + dt_type(next->d_inode)) < 0) return 0; spin_lock(&dcache_lock); /* next is still alive */ - list_del(q); - list_add(q, p); + list_move(q, p); p = q; filp->f_pos++; } @@ -188,20 +192,23 @@ const struct file_operations simple_dir_operations = { .fsync = simple_sync_file, }; -struct inode_operations simple_dir_inode_operations = { +const struct inode_operations simple_dir_inode_operations = { .lookup = simple_lookup, }; +static const struct super_operations simple_super_operations = { + .statfs = simple_statfs, +}; + /* * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that * will never be mountable) */ int get_sb_pseudo(struct file_system_type *fs_type, char *name, - struct super_operations *ops, unsigned long magic, + const struct super_operations *ops, unsigned long magic, struct vfsmount *mnt) { struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL); - static struct super_operations default_ops = {.statfs = simple_statfs}; struct dentry *dentry; struct inode *root; struct qstr d_name = {.name = name, .len = strlen(name)}; @@ -210,17 +217,22 @@ int get_sb_pseudo(struct file_system_type *fs_type, char *name, return PTR_ERR(s); s->s_flags = MS_NOUSER; - s->s_maxbytes = ~0ULL; - s->s_blocksize = 1024; - s->s_blocksize_bits = 10; + s->s_maxbytes = MAX_LFS_FILESIZE; + s->s_blocksize = PAGE_SIZE; + s->s_blocksize_bits = PAGE_SHIFT; s->s_magic = magic; - s->s_op = ops ? ops : &default_ops; + s->s_op = ops ? ops : &simple_super_operations; s->s_time_gran = 1; root = new_inode(s); if (!root) goto Enomem; + /* + * since this is the first inode, make it number 1. New inodes created + * after this must take care not to collide with it (by passing + * max_reserved of 1 to iunique). + */ + root->i_ino = 1; root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; - root->i_uid = root->i_gid = 0; root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; dentry = d_alloc(NULL, &d_name); if (!dentry) { @@ -232,11 +244,11 @@ int get_sb_pseudo(struct file_system_type *fs_type, char *name, d_instantiate(dentry, root); s->s_root = dentry; s->s_flags |= MS_ACTIVE; - return simple_set_mnt(mnt, s); + simple_set_mnt(mnt, s); + return 0; Enomem: - up_write(&s->s_umount); - deactivate_super(s); + deactivate_locked_super(s); return -ENOMEM; } @@ -245,7 +257,7 @@ int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *den struct inode *inode = old_dentry->d_inode; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; - inode->i_nlink++; + inc_nlink(inode); atomic_inc(&inode->i_count); dget(dentry); d_instantiate(dentry, inode); @@ -277,7 +289,7 @@ int simple_unlink(struct inode *dir, struct dentry *dentry) struct inode *inode = dentry->d_inode; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; - inode->i_nlink--; + drop_nlink(inode); dput(dentry); return 0; } @@ -287,9 +299,9 @@ int simple_rmdir(struct inode *dir, struct dentry *dentry) if (!simple_empty(dentry)) return -ENOTEMPTY; - dentry->d_inode->i_nlink--; + drop_nlink(dentry->d_inode); simple_unlink(dir, dentry); - dir->i_nlink--; + drop_nlink(dir); return 0; } @@ -305,10 +317,10 @@ int simple_rename(struct inode *old_dir, struct dentry *old_dentry, if (new_dentry->d_inode) { simple_unlink(new_dir, new_dentry); if (they_are_dirs) - old_dir->i_nlink--; + drop_nlink(old_dir); } else if (they_are_dirs) { - old_dir->i_nlink--; - new_dir->i_nlink++; + drop_nlink(old_dir); + inc_nlink(new_dir); } old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = @@ -319,17 +331,9 @@ int simple_rename(struct inode *old_dir, struct dentry *old_dentry, int simple_readpage(struct file *file, struct page *page) { - void *kaddr; - - if (PageUptodate(page)) - goto out; - - kaddr = kmap_atomic(page, KM_USER0); - memset(kaddr, 0, PAGE_CACHE_SIZE); - kunmap_atomic(kaddr, KM_USER0); + clear_highpage(page); flush_dcache_page(page); SetPageUptodate(page); -out: unlock_page(page); return 0; } @@ -338,24 +342,42 @@ int simple_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { if (!PageUptodate(page)) { - if (to - from != PAGE_CACHE_SIZE) { - void *kaddr = kmap_atomic(page, KM_USER0); - memset(kaddr, 0, from); - memset(kaddr + to, 0, PAGE_CACHE_SIZE - to); - flush_dcache_page(page); - kunmap_atomic(kaddr, KM_USER0); - } - SetPageUptodate(page); + if (to - from != PAGE_CACHE_SIZE) + zero_user_segments(page, + 0, from, + to, PAGE_CACHE_SIZE); } return 0; } -int simple_commit_write(struct file *file, struct page *page, - unsigned offset, unsigned to) +int simple_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) +{ + struct page *page; + pgoff_t index; + unsigned from; + + index = pos >> PAGE_CACHE_SHIFT; + from = pos & (PAGE_CACHE_SIZE - 1); + + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; + + *pagep = page; + + return simple_prepare_write(file, page, from, from+len); +} + +static int simple_commit_write(struct file *file, struct page *page, + unsigned from, unsigned to) { struct inode *inode = page->mapping->host; loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; + if (!PageUptodate(page)) + SetPageUptodate(page); /* * No need to use i_size_read() here, the i_size * cannot change under us because we hold the i_mutex. @@ -366,9 +388,35 @@ int simple_commit_write(struct file *file, struct page *page, return 0; } +int simple_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + unsigned from = pos & (PAGE_CACHE_SIZE - 1); + + /* zero the stale part of the page if we did a short copy */ + if (copied < len) { + void *kaddr = kmap_atomic(page, KM_USER0); + memset(kaddr + from + copied, 0, len - copied); + flush_dcache_page(page); + kunmap_atomic(kaddr, KM_USER0); + } + + simple_commit_write(file, page, from, from+copied); + + unlock_page(page); + page_cache_release(page); + + return copied; +} + +/* + * the inodes created here are not hashed. If you use iunique to generate + * unique inode values later for this filesystem, then you must take care + * to pass it an appropriate max_reserved value to avoid collisions. + */ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files) { - static struct super_operations s_ops = {.statfs = simple_statfs}; struct inode *inode; struct dentry *root; struct dentry *dentry; @@ -377,16 +425,18 @@ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files s->s_blocksize = PAGE_CACHE_SIZE; s->s_blocksize_bits = PAGE_CACHE_SHIFT; s->s_magic = magic; - s->s_op = &s_ops; + s->s_op = &simple_super_operations; s->s_time_gran = 1; inode = new_inode(s); if (!inode) return -ENOMEM; + /* + * because the root inode is 1, the files array must not contain an + * entry at index 1 + */ + inode->i_ino = 1; inode->i_mode = S_IFDIR | 0755; - inode->i_uid = inode->i_gid = 0; - inode->i_blksize = PAGE_CACHE_SIZE; - inode->i_blocks = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; @@ -399,6 +449,13 @@ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files for (i = 0; !files->name || files->name[0]; i++, files++) { if (!files->name) continue; + + /* warn if it tries to conflict with the root inode */ + if (unlikely(i == 1)) + printk(KERN_WARNING "%s: %s passed in a files array" + "with an index of 1!\n", __func__, + s->s_type->name); + dentry = d_alloc_name(root, files->name); if (!dentry) goto out; @@ -406,9 +463,6 @@ int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files if (!inode) goto out; inode->i_mode = S_IFREG | files->mode; - inode->i_uid = inode->i_gid = 0; - inode->i_blksize = PAGE_CACHE_SIZE; - inode->i_blocks = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_fop = files->ops; inode->i_ino = i; @@ -455,19 +509,68 @@ void simple_release_fs(struct vfsmount **mount, int *count) mntput(mnt); } +/** + * simple_read_from_buffer - copy data from the buffer to user space + * @to: the user space buffer to read to + * @count: the maximum number of bytes to read + * @ppos: the current position in the buffer + * @from: the buffer to read from + * @available: the size of the buffer + * + * The simple_read_from_buffer() function reads up to @count bytes from the + * buffer @from at offset @ppos into the user space address starting at @to. + * + * On success, the number of bytes read is returned and the offset @ppos is + * advanced by this number, or negative value is returned on error. + **/ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, const void *from, size_t available) { loff_t pos = *ppos; + size_t ret; + if (pos < 0) return -EINVAL; - if (pos >= available) + if (pos >= available || !count) return 0; if (count > available - pos) count = available - pos; - if (copy_to_user(to, from + pos, count)) + ret = copy_to_user(to, from + pos, count); + if (ret == count) return -EFAULT; + count -= ret; + *ppos = pos + count; + return count; +} + +/** + * memory_read_from_buffer - copy data from the buffer + * @to: the kernel space buffer to read to + * @count: the maximum number of bytes to read + * @ppos: the current position in the buffer + * @from: the buffer to read from + * @available: the size of the buffer + * + * The memory_read_from_buffer() function reads up to @count bytes from the + * buffer @from at offset @ppos into the kernel space address starting at @to. + * + * On success, the number of bytes read is returned and the offset @ppos is + * advanced by this number, or negative value is returned on error. + **/ +ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, + const void *from, size_t available) +{ + loff_t pos = *ppos; + + if (pos < 0) + return -EINVAL; + if (pos >= available) + return 0; + if (count > available - pos) + count = available - pos; + memcpy(to, from + pos, count); *ppos = pos + count; + return count; } @@ -477,6 +580,21 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, * possibly a read which collects the result - which is stored in a * file-local buffer. */ + +void simple_transaction_set(struct file *file, size_t n) +{ + struct simple_transaction_argresp *ar = file->private_data; + + BUG_ON(n > SIMPLE_TRANSACTION_LIMIT); + + /* + * The barrier ensures that ar->size will really remain zero until + * ar->data is ready for reading. + */ + smp_mb(); + ar->size = n; +} + char *simple_transaction_get(struct file *file, const char __user *buf, size_t size) { struct simple_transaction_argresp *ar; @@ -526,8 +644,8 @@ int simple_transaction_release(struct inode *inode, struct file *file) /* Simple attribute files */ struct simple_attr { - u64 (*get)(void *); - void (*set)(void *, u64); + int (*get)(void *, u64 *); + int (*set)(void *, u64); char get_buf[24]; /* enough to store a u64 and "\n\0" */ char set_buf[24]; void *data; @@ -538,7 +656,7 @@ struct simple_attr { /* simple_attr_open is called by an actual attribute open file operation * to set the attribute specific access operations. */ int simple_attr_open(struct inode *inode, struct file *file, - u64 (*get)(void *), void (*set)(void *, u64), + int (*get)(void *, u64 *), int (*set)(void *, u64), const char *fmt) { struct simple_attr *attr; @@ -549,7 +667,7 @@ int simple_attr_open(struct inode *inode, struct file *file, attr->get = get; attr->set = set; - attr->data = inode->u.generic_ip; + attr->data = inode->i_private; attr->fmt = fmt; mutex_init(&attr->mutex); @@ -558,7 +676,7 @@ int simple_attr_open(struct inode *inode, struct file *file, return nonseekable_open(inode, file); } -int simple_attr_close(struct inode *inode, struct file *file) +int simple_attr_release(struct inode *inode, struct file *file) { kfree(file->private_data); return 0; @@ -577,15 +695,24 @@ ssize_t simple_attr_read(struct file *file, char __user *buf, if (!attr->get) return -EACCES; - mutex_lock(&attr->mutex); - if (*ppos) /* continued read */ + ret = mutex_lock_interruptible(&attr->mutex); + if (ret) + return ret; + + if (*ppos) { /* continued read */ size = strlen(attr->get_buf); - else /* first read */ + } else { /* first read */ + u64 val; + ret = attr->get(attr->data, &val); + if (ret) + goto out; + size = scnprintf(attr->get_buf, sizeof(attr->get_buf), - attr->fmt, - (unsigned long long)attr->get(attr->data)); + attr->fmt, (unsigned long long)val); + } ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size); +out: mutex_unlock(&attr->mutex); return ret; } @@ -600,42 +727,133 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf, ssize_t ret; attr = file->private_data; - if (!attr->set) return -EACCES; - mutex_lock(&attr->mutex); + ret = mutex_lock_interruptible(&attr->mutex); + if (ret) + return ret; + ret = -EFAULT; size = min(sizeof(attr->set_buf) - 1, len); if (copy_from_user(attr->set_buf, buf, size)) goto out; - ret = len; /* claim we got the whole input */ attr->set_buf[size] = '\0'; val = simple_strtol(attr->set_buf, NULL, 0); - attr->set(attr->data, val); + ret = attr->set(attr->data, val); + if (ret == 0) + ret = len; /* on success, claim we got the whole input */ out: mutex_unlock(&attr->mutex); return ret; } +/** + * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation + * @sb: filesystem to do the file handle conversion on + * @fid: file handle to convert + * @fh_len: length of the file handle in bytes + * @fh_type: type of file handle + * @get_inode: filesystem callback to retrieve inode + * + * This function decodes @fid as long as it has one of the well-known + * Linux filehandle types and calls @get_inode on it to retrieve the + * inode for the object specified in the file handle. + */ +struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type, struct inode *(*get_inode) + (struct super_block *sb, u64 ino, u32 gen)) +{ + struct inode *inode = NULL; + + if (fh_len < 2) + return NULL; + + switch (fh_type) { + case FILEID_INO32_GEN: + case FILEID_INO32_GEN_PARENT: + inode = get_inode(sb, fid->i32.ino, fid->i32.gen); + break; + } + + return d_obtain_alias(inode); +} +EXPORT_SYMBOL_GPL(generic_fh_to_dentry); + +/** + * generic_fh_to_dentry - generic helper for the fh_to_parent export operation + * @sb: filesystem to do the file handle conversion on + * @fid: file handle to convert + * @fh_len: length of the file handle in bytes + * @fh_type: type of file handle + * @get_inode: filesystem callback to retrieve inode + * + * This function decodes @fid as long as it has one of the well-known + * Linux filehandle types and calls @get_inode on it to retrieve the + * inode for the _parent_ object specified in the file handle if it + * is specified in the file handle, or NULL otherwise. + */ +struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type, struct inode *(*get_inode) + (struct super_block *sb, u64 ino, u32 gen)) +{ + struct inode *inode = NULL; + + if (fh_len <= 2) + return NULL; + + switch (fh_type) { + case FILEID_INO32_GEN_PARENT: + inode = get_inode(sb, fid->i32.parent_ino, + (fh_len > 3 ? fid->i32.parent_gen : 0)); + break; + } + + return d_obtain_alias(inode); +} +EXPORT_SYMBOL_GPL(generic_fh_to_parent); + +int simple_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .nr_to_write = 0, /* metadata-only; caller takes care of data */ + }; + struct inode *inode = dentry->d_inode; + int err; + int ret; + + ret = sync_mapping_buffers(inode->i_mapping); + if (!(inode->i_state & I_DIRTY)) + return ret; + if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) + return ret; + + err = sync_inode(inode, &wbc); + if (ret == 0) + ret = err; + return ret; +} +EXPORT_SYMBOL(simple_fsync); + EXPORT_SYMBOL(dcache_dir_close); EXPORT_SYMBOL(dcache_dir_lseek); EXPORT_SYMBOL(dcache_dir_open); EXPORT_SYMBOL(dcache_readdir); EXPORT_SYMBOL(generic_read_dir); EXPORT_SYMBOL(get_sb_pseudo); -EXPORT_SYMBOL(simple_commit_write); +EXPORT_SYMBOL(simple_write_begin); +EXPORT_SYMBOL(simple_write_end); EXPORT_SYMBOL(simple_dir_inode_operations); EXPORT_SYMBOL(simple_dir_operations); EXPORT_SYMBOL(simple_empty); -EXPORT_SYMBOL(d_alloc_name); EXPORT_SYMBOL(simple_fill_super); EXPORT_SYMBOL(simple_getattr); EXPORT_SYMBOL(simple_link); EXPORT_SYMBOL(simple_lookup); EXPORT_SYMBOL(simple_pin_fs); -EXPORT_SYMBOL(simple_prepare_write); +EXPORT_UNUSED_SYMBOL(simple_prepare_write); EXPORT_SYMBOL(simple_readpage); EXPORT_SYMBOL(simple_release_fs); EXPORT_SYMBOL(simple_rename); @@ -644,10 +862,12 @@ EXPORT_SYMBOL(simple_statfs); EXPORT_SYMBOL(simple_sync_file); EXPORT_SYMBOL(simple_unlink); EXPORT_SYMBOL(simple_read_from_buffer); +EXPORT_SYMBOL(memory_read_from_buffer); +EXPORT_SYMBOL(simple_transaction_set); EXPORT_SYMBOL(simple_transaction_get); EXPORT_SYMBOL(simple_transaction_read); EXPORT_SYMBOL(simple_transaction_release); EXPORT_SYMBOL_GPL(simple_attr_open); -EXPORT_SYMBOL_GPL(simple_attr_close); +EXPORT_SYMBOL_GPL(simple_attr_release); EXPORT_SYMBOL_GPL(simple_attr_read); EXPORT_SYMBOL_GPL(simple_attr_write);