diff options
| -rw-r--r-- | fs/cramfs/inode.c | 110 |
1 files changed, 69 insertions, 41 deletions
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index 32fd5fe9ca0e..e141939080f0 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -34,57 +34,81 @@ static const struct address_space_operations cramfs_aops; static DEFINE_MUTEX(read_mutex); -/* These two macros may change in future, to provide better st_ino - semantics. */ -#define CRAMINO(x) (((x)->offset && (x)->size)?(x)->offset<<2:1) +/* These macros may change in future, to provide better st_ino semantics. */ #define OFFSET(x) ((x)->i_ino) -static void setup_inode(struct inode *inode, struct cramfs_inode * cramfs_inode) +static unsigned long cramino(struct cramfs_inode *cino, unsigned int offset) { + if (!cino->offset) + return offset + 1; + if (!cino->size) + return offset + 1; + + /* + * The file mode test fixes buggy mkcramfs implementations where + * cramfs_inode->offset is set to a non zero value for entries + * which did not contain data, like devices node and fifos. + */ + switch (cino->mode & S_IFMT) { + case S_IFREG: + case S_IFDIR: + case S_IFLNK: + return cino->offset << 2; + default: + break; + } + return offset + 1; +} + +static struct inode *get_cramfs_inode(struct super_block *sb, + struct cramfs_inode *cramfs_inode, unsigned int offset) +{ + struct inode *inode; static struct timespec zerotime; + + inode = iget_locked(sb, cramino(cramfs_inode, offset)); + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + + switch (cramfs_inode->mode & S_IFMT) { + case S_IFREG: + inode->i_fop = &generic_ro_fops; + inode->i_data.a_ops = &cramfs_aops; + break; + case S_IFDIR: + inode->i_op = &cramfs_dir_inode_operations; + inode->i_fop = &cramfs_directory_operations; + break; + case S_IFLNK: + inode->i_op = &page_symlink_inode_operations; + inode->i_data.a_ops = &cramfs_aops; + break; + default: + init_special_inode(inode, cramfs_inode->mode, + old_decode_dev(cramfs_inode->size)); + } + inode->i_mode = cramfs_inode->mode; inode->i_uid = cramfs_inode->uid; - inode->i_size = cramfs_inode->size; - inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1; inode->i_gid = cramfs_inode->gid; + + /* if the lower 2 bits are zero, the inode contains data */ + if (!(inode->i_ino & 3)) { + inode->i_size = cramfs_inode->size; + inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1; + } + /* Struct copy intentional */ inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime; /* inode->i_nlink is left 1 - arguably wrong for directories, but it's the best we can do without reading the directory contents. 1 yields the right result in GNU find, even without -noleaf option. */ - if (S_ISREG(inode->i_mode)) { - inode->i_fop = &generic_ro_fops; - inode->i_data.a_ops = &cramfs_aops; - } else if (S_ISDIR(inode->i_mode)) { - inode->i_op = &cramfs_dir_inode_operations; - inode->i_fop = &cramfs_directory_operations; - } else if (S_ISLNK(inode->i_mode)) { - inode->i_op = &page_symlink_inode_operations; - inode->i_data.a_ops = &cramfs_aops; - } else { - init_special_inode(inode, inode->i_mode, - old_decode_dev(cramfs_inode->size)); - } -} -static struct inode *get_cramfs_inode(struct super_block *sb, - struct cramfs_inode * cramfs_inode) -{ - struct inode *inode; - if (CRAMINO(cramfs_inode) == 1) { - inode = new_inode(sb); - if (inode) { - inode->i_ino = 1; - setup_inode(inode, cramfs_inode); - } - } else { - inode = iget_locked(sb, CRAMINO(cramfs_inode)); - if (inode && (inode->i_state & I_NEW)) { - setup_inode(inode, cramfs_inode); - unlock_new_inode(inode); - } - } + unlock_new_inode(inode); + return inode; } @@ -265,6 +289,9 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent) printk(KERN_ERR "cramfs: root is not a directory\n"); goto out; } + /* correct strange, hard-coded permissions of mkcramfs */ + super.root.mode |= (S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH); + root_offset = super.root.offset << 2; if (super.flags & CRAMFS_FLAG_FSID_VERSION_2) { sbi->size=super.size; @@ -289,7 +316,7 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent) /* Set it all up.. */ sb->s_op = &cramfs_ops; - root = get_cramfs_inode(sb, &super.root); + root = get_cramfs_inode(sb, &super.root, 0); if (!root) goto out; sb->s_root = d_alloc_root(root); @@ -365,7 +392,7 @@ static int cramfs_readdir(struct file *filp, void *dirent, filldir_t filldir) */ namelen = de->namelen << 2; memcpy(buf, name, namelen); - ino = CRAMINO(de); + ino = cramino(de, OFFSET(inode) + offset); mode = de->mode; mutex_unlock(&read_mutex); nextoffset = offset + sizeof(*de) + namelen; @@ -404,8 +431,9 @@ static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, s struct cramfs_inode *de; char *name; int namelen, retval; + int dir_off = OFFSET(dir) + offset; - de = cramfs_read(dir->i_sb, OFFSET(dir) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN); + de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN); name = (char *)(de+1); /* Try to take advantage of sorted directories */ @@ -436,7 +464,7 @@ static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, s if (!retval) { struct cramfs_inode entry = *de; mutex_unlock(&read_mutex); - d_add(dentry, get_cramfs_inode(dir->i_sb, &entry)); + d_add(dentry, get_cramfs_inode(dir->i_sb, &entry, dir_off)); return NULL; } /* else (retval < 0) */ |