diff options
Diffstat (limited to 'fs/jffs2/dir.c')
| -rw-r--r-- | fs/jffs2/dir.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c new file mode 100644 index 0000000000..4d28d2b553 --- /dev/null +++ b/fs/jffs2/dir.c @@ -0,0 +1,135 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2001-2007 Red Hat, Inc. + * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> + * + * Created by David Woodhouse <dwmw2@infradead.org> + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <common.h> +#include <linux/fs.h> +#include <linux/hash.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/jffs2.h> +#include "jffs2_fs_i.h" +#include "jffs2_fs_sb.h" +#include <linux/time.h> +#include "nodelist.h" + +static int jffs2_readdir (struct file *, struct dir_context *); + +static struct dentry *jffs2_lookup (struct inode *,struct dentry *, + unsigned int); + +const struct file_operations jffs2_dir_operations = +{ + .read = NULL, + .iterate = jffs2_readdir, +}; + +const struct inode_operations jffs2_dir_inode_operations = +{ + .lookup = jffs2_lookup, + .create = NULL, /* not present in barebox */ + .link = NULL, /* not present in barebox */ + .symlink = NULL, /* not present in barebox */ + .unlink = NULL, /* not present in barebox */ + .mkdir = NULL, /* not present in barebox */ + .rmdir = NULL, /* not present in barebox */ +}; + +/***********************************************************************/ + +/* We keep the dirent list sorted in increasing order of name hash, + and we use the same hash function as the dentries. Makes this + nice and simple +*/ +static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target, + unsigned int flags) +{ + struct jffs2_inode_info *dir_f; + struct jffs2_full_dirent *fd = NULL, *fd_list; + uint32_t ino = 0; + struct inode *inode = NULL; + unsigned int nhash; + + jffs2_dbg(1, "jffs2_lookup()\n"); + + if (target->d_name.len > JFFS2_MAX_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + dir_f = JFFS2_INODE_INFO(dir_i); + + /* The 'nhash' on the fd_list is not the same as the dentry hash */ + nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len); + + mutex_lock(&dir_f->sem); + + /* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */ + for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) { + if (fd_list->nhash == nhash && + (!fd || fd_list->version > fd->version) && + strlen(fd_list->name) == target->d_name.len && + !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) { + fd = fd_list; + } + } + if (fd) + ino = fd->ino; + mutex_unlock(&dir_f->sem); + if (ino) { + inode = jffs2_iget(dir_i->i_sb, ino); + if (IS_ERR(inode)) + pr_warn("iget() failed for ino #%u\n", ino); + } + + if (IS_ERR(inode)) + return ERR_CAST(inode); + d_add(target, inode); + return NULL; +} + +/***********************************************************************/ + + +static int jffs2_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); + struct jffs2_full_dirent *fd; + unsigned long curofs = 1; + + jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino); + + if (!dir_emit_dots(file, ctx)) + return 0; + + mutex_lock(&f->sem); + for (fd = f->dents; fd; fd = fd->next) { + curofs++; + /* First loop: curofs = 2; pos = 2 */ + if (curofs < ctx->pos) { + jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n", + fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos); + continue; + } + if (!fd->ino) { + jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n", + fd->name); + ctx->pos++; + continue; + } + jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n", + (unsigned long)ctx->pos, fd->name, fd->ino, fd->type); + if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type)) + break; + ctx->pos++; + } + mutex_unlock(&f->sem); + return 0; +} |