diff options
Diffstat (limited to 'fs/libfs.c')
| -rw-r--r-- | fs/libfs.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index ae51481e45e5..6e68b700958d 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -8,6 +8,7 @@ #include <linux/mount.h> #include <linux/vfs.h> #include <linux/mutex.h> +#include <linux/exportfs.h> #include <asm/uaccess.h> @@ -678,6 +679,93 @@ 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); |