From: Christoph Hellwig Date: Sun, 21 Oct 2007 23:42:11 +0000 (-0700) Subject: xfs: new export ops X-Git-Tag: v2.6.24-rc1~81 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c38344fe9e73c99d546cc15a2bb97c7a09942aad;p=linux-2.6 xfs: new export ops This one is a lot more complicated than the previous ones. XFS already had a very clever scheme for supporting 64bit inode numbers in filehandles, and I've reworked this to be some kind of a prototype for the generic 64bit inode filehandle support. Signed-off-by: Christoph Hellwig Cc: Neil Brown Cc: "J. Bruce Fields" Cc: David Chinner Cc: Timothy Shimmin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/xfs/linux-2.6/xfs_export.c b/fs/xfs/linux-2.6/xfs_export.c index 3586c7a28d..7178d61f00 100644 --- a/fs/xfs/linux-2.6/xfs_export.c +++ b/fs/xfs/linux-2.6/xfs_export.c @@ -33,62 +33,25 @@ static struct dentry dotdot = { .d_name.name = "..", .d_name.len = 2, }; /* - * XFS encodes and decodes the fileid portion of NFS filehandles - * itself instead of letting the generic NFS code do it. This - * allows filesystems with 64 bit inode numbers to be exported. - * - * Note that a side effect is that xfs_vget() won't be passed a - * zero inode/generation pair under normal circumstances. As - * however a malicious client could send us such data, the check - * remains in that code. + * Note that we only accept fileids which are long enough rather than allow + * the parent generation number to default to zero. XFS considers zero a + * valid generation number not an invalid/wildcard value. */ - -STATIC struct dentry * -xfs_fs_decode_fh( - struct super_block *sb, - __u32 *fh, - int fh_len, - int fileid_type, - int (*acceptable)( - void *context, - struct dentry *de), - void *context) +static int xfs_fileid_length(int fileid_type) { - xfs_fid_t ifid; - xfs_fid_t pfid; - void *parent = NULL; - int is64 = 0; - __u32 *p = fh; - -#if XFS_BIG_INUMS - is64 = (fileid_type & XFS_FILEID_TYPE_64FLAG); - fileid_type &= ~XFS_FILEID_TYPE_64FLAG; -#endif - - /* - * Note that we only accept fileids which are long enough - * rather than allow the parent generation number to default - * to zero. XFS considers zero a valid generation number not - * an invalid/wildcard value. There's little point printk'ing - * a warning here as we don't have the client information - * which would make such a warning useful. - */ - if (fileid_type > 2 || - fh_len < xfs_fileid_length((fileid_type == 2), is64)) - return NULL; - - p = xfs_fileid_decode_fid2(p, &ifid, is64); - - if (fileid_type == 2) { - p = xfs_fileid_decode_fid2(p, &pfid, is64); - parent = &pfid; + switch (fileid_type) { + case FILEID_INO32_GEN: + return 2; + case FILEID_INO32_GEN_PARENT: + return 4; + case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: + return 3; + case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: + return 6; } - - fh = (__u32 *)&ifid; - return sb->s_export_op->find_exported_dentry(sb, fh, parent, acceptable, context); + return 255; /* invalid */ } - STATIC int xfs_fs_encode_fh( struct dentry *dentry, @@ -96,21 +59,21 @@ xfs_fs_encode_fh( int *max_len, int connectable) { + struct fid *fid = (struct fid *)fh; + struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh; struct inode *inode = dentry->d_inode; - int type = 1; - __u32 *p = fh; + int fileid_type; int len; - int is64 = 0; -#if XFS_BIG_INUMS - if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS)) { - /* filesystem may contain 64bit inode numbers */ - is64 = XFS_FILEID_TYPE_64FLAG; - } -#endif /* Directories don't need their parent encoded, they have ".." */ if (S_ISDIR(inode->i_mode)) - connectable = 0; + fileid_type = FILEID_INO32_GEN; + else + fileid_type = FILEID_INO32_GEN_PARENT; + + /* filesystem may contain 64bit inode numbers */ + if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS)) + fileid_type |= XFS_FILEID_TYPE_64FLAG; /* * Only encode if there is enough space given. In practice @@ -118,39 +81,118 @@ xfs_fs_encode_fh( * over NFSv2 with the subtree_check export option; the other * seven combinations work. The real answer is "don't use v2". */ - len = xfs_fileid_length(connectable, is64); + len = xfs_fileid_length(fileid_type); if (*max_len < len) return 255; *max_len = len; - p = xfs_fileid_encode_inode(p, inode, is64); - if (connectable) { + switch (fileid_type) { + case FILEID_INO32_GEN_PARENT: spin_lock(&dentry->d_lock); - p = xfs_fileid_encode_inode(p, dentry->d_parent->d_inode, is64); + fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino; + fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation; spin_unlock(&dentry->d_lock); - type = 2; + /*FALLTHRU*/ + case FILEID_INO32_GEN: + fid->i32.ino = inode->i_ino; + fid->i32.gen = inode->i_generation; + break; + case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: + spin_lock(&dentry->d_lock); + fid64->parent_ino = dentry->d_parent->d_inode->i_ino; + fid64->parent_gen = dentry->d_parent->d_inode->i_generation; + spin_unlock(&dentry->d_lock); + /*FALLTHRU*/ + case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: + fid64->ino = inode->i_ino; + fid64->gen = inode->i_generation; + break; } - BUG_ON((p - fh) != len); - return type | is64; + + return fileid_type; } -STATIC struct dentry * -xfs_fs_get_dentry( +STATIC struct inode * +xfs_nfs_get_inode( struct super_block *sb, - void *data) -{ + u64 ino, + u32 generation) + { + xfs_fid_t xfid; bhv_vnode_t *vp; - struct inode *inode; - struct dentry *result; int error; - error = xfs_vget(XFS_M(sb), &vp, data); - if (error || vp == NULL) - return ERR_PTR(-ESTALE) ; + xfid.fid_len = sizeof(xfs_fid_t) - sizeof(xfid.fid_len); + xfid.fid_pad = 0; + xfid.fid_ino = ino; + xfid.fid_gen = generation; - inode = vn_to_inode(vp); + error = xfs_vget(XFS_M(sb), &vp, &xfid); + if (error) + return ERR_PTR(-error); + + return vp ? vn_to_inode(vp) : NULL; +} + +STATIC struct dentry * +xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fileid_type) +{ + struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; + struct inode *inode = NULL; + struct dentry *result; + + if (fh_len < xfs_fileid_length(fileid_type)) + return NULL; + + switch (fileid_type) { + case FILEID_INO32_GEN_PARENT: + case FILEID_INO32_GEN: + inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen); + break; + case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: + case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: + inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen); + break; + } + + if (!inode) + return NULL; + if (IS_ERR(inode)) + return ERR_PTR(PTR_ERR(inode)); + result = d_alloc_anon(inode); + if (!result) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + return result; +} + +STATIC struct dentry * +xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fileid_type) +{ + struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; + struct inode *inode = NULL; + struct dentry *result; + + switch (fileid_type) { + case FILEID_INO32_GEN_PARENT: + inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino, + fid->i32.parent_gen); + break; + case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: + inode = xfs_nfs_get_inode(sb, fid64->parent_ino, + fid64->parent_gen); + break; + } + + if (!inode) + return NULL; + if (IS_ERR(inode)) + return ERR_PTR(PTR_ERR(inode)); result = d_alloc_anon(inode); - if (!result) { + if (!result) { iput(inode); return ERR_PTR(-ENOMEM); } @@ -179,8 +221,8 @@ xfs_fs_get_parent( } struct export_operations xfs_export_operations = { - .decode_fh = xfs_fs_decode_fh, .encode_fh = xfs_fs_encode_fh, + .fh_to_dentry = xfs_fs_fh_to_dentry, + .fh_to_parent = xfs_fs_fh_to_parent, .get_parent = xfs_fs_get_parent, - .get_dentry = xfs_fs_get_dentry, }; diff --git a/fs/xfs/linux-2.6/xfs_export.h b/fs/xfs/linux-2.6/xfs_export.h index 2f36071a86..3272b6ae7a 100644 --- a/fs/xfs/linux-2.6/xfs_export.h +++ b/fs/xfs/linux-2.6/xfs_export.h @@ -59,50 +59,14 @@ * a subdirectory) or use the "fsid" export option. */ +struct xfs_fid64 { + u64 ino; + u32 gen; + u64 parent_ino; + u32 parent_gen; +} __attribute__((packed)); + /* This flag goes on the wire. Don't play with it. */ #define XFS_FILEID_TYPE_64FLAG 0x80 /* NFS fileid has 64bit inodes */ -/* Calculate the length in u32 units of the fileid data */ -static inline int -xfs_fileid_length(int hasparent, int is64) -{ - return hasparent ? (is64 ? 6 : 4) : (is64 ? 3 : 2); -} - -/* - * Decode encoded inode information (either for the inode itself - * or the parent) into an xfs_fid_t structure. Advances and - * returns the new data pointer - */ -static inline __u32 * -xfs_fileid_decode_fid2(__u32 *p, xfs_fid_t *fid, int is64) -{ - fid->fid_len = sizeof(xfs_fid_t) - sizeof(fid->fid_len); - fid->fid_pad = 0; - fid->fid_ino = *p++; -#if XFS_BIG_INUMS - if (is64) - fid->fid_ino |= (((__u64)(*p++)) << 32); -#endif - fid->fid_gen = *p++; - return p; -} - -/* - * Encode inode information (either for the inode itself or the - * parent) into a fileid buffer. Advances and returns the new - * data pointer. - */ -static inline __u32 * -xfs_fileid_encode_inode(__u32 *p, struct inode *inode, int is64) -{ - *p++ = (__u32)inode->i_ino; -#if XFS_BIG_INUMS - if (is64) - *p++ = (__u32)(inode->i_ino >> 32); -#endif - *p++ = inode->i_generation; - return p; -} - #endif /* __XFS_EXPORT_H__ */