X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Flibfs.c;h=cf79196535ec5fc277f2dc9f190a3cc7e551dcd6;hb=eebd2aa355692afaf9906f62118620f1a1c19dbb;hp=bd08e0e64a8caa8731c9ee5ccbd37962eb658298;hpb=63c422afe3739b68bec0b5c42807d1450c951caf;p=linux-2.6 diff --git a/fs/libfs.c b/fs/libfs.c index bd08e0e64a..5523bde963 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -8,6 +8,7 @@ #include #include #include +#include #include @@ -63,7 +64,7 @@ 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 +77,7 @@ 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 +85,7 @@ 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 +97,8 @@ 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 +109,7 @@ 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 +127,7 @@ 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; @@ -159,7 +160,10 @@ 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 */ @@ -186,20 +190,23 @@ 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)}; @@ -212,11 +219,17 @@ int get_sb_pseudo(struct file_system_type *fs_type, char *name, s->s_blocksize = 1024; s->s_blocksize_bits = 10; 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; @@ -328,24 +341,42 @@ 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(mapping, index); + 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. @@ -356,9 +387,35 @@ 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; @@ -367,12 +424,17 @@ 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_blocks = 0; @@ -388,6 +450,13 @@ 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; @@ -607,13 +676,101 @@ out: return ret; } +/* + * This is what d_alloc_anon should have been. Once the exportfs + * argument transition has been finished I will update d_alloc_anon + * to this prototype and this wrapper will go away. --hch + */ +static struct dentry *exportfs_d_alloc(struct inode *inode) +{ + struct dentry *dentry; + + if (!inode) + return NULL; + if (IS_ERR(inode)) + return ERR_PTR(PTR_ERR(inode)); + + dentry = d_alloc_anon(inode); + if (!dentry) { + iput(inode); + dentry = ERR_PTR(-ENOMEM); + } + return dentry; +} + +/** + * 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 exportfs_d_alloc(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 exportfs_d_alloc(inode); +} +EXPORT_SYMBOL_GPL(generic_fh_to_parent); + 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);