diff options
author | Christoph Hellwig <hch@lst.de> | 2007-10-22 03:42:05 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-22 19:13:19 +0400 |
commit | 2596110a3994593f6aa3e2bb76345ad4791b1a14 (patch) | |
tree | 0f1773238265f83e1b5640256176851a60ff5ea8 /fs/libfs.c | |
parent | 6e91ea2bb0b6a3ddf6d4faeb54a9c20d4e20bc42 (diff) |
exportfs: add new methods
Add the guts for the new filesystem API to exportfs.
There's now a fh_to_dentry method that returns a dentry for the object looked
for given a filehandle fragment, and a fh_to_parent operation that returns the
dentry for the encoded parent directory in case the file handle contains it.
There are default implementations for these methods that only take a callback
for an nfs-enhanced iget variant and implement the rest of the semantics.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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); |