From 5fe0c2378884e68beb532f5890cc0e3539ac747b Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Sat, 29 Jan 2011 18:43:25 +0530 Subject: exportfs: Return the minimum required handle size The exportfs encode handle function should return the minimum required handle size. This helps user to find out the handle size by passing 0 handle size in the first step and then redoing to the call again with the returned handle size value. Acked-by: Serge Hallyn Signed-off-by: Aneesh Kumar K.V Signed-off-by: Al Viro --- fs/btrfs/export.c | 8 ++++++-- fs/exportfs/expfs.c | 9 +++++++-- fs/fat/inode.c | 4 +++- fs/fuse/inode.c | 4 +++- fs/gfs2/export.c | 8 ++++++-- fs/isofs/export.c | 8 ++++++-- fs/ocfs2/export.c | 8 ++++++-- fs/reiserfs/inode.c | 7 ++++++- fs/udf/namei.c | 7 ++++++- fs/xfs/linux-2.6/xfs_export.c | 4 +++- include/linux/exportfs.h | 6 ++++-- mm/shmem.c | 4 +++- 12 files changed, 59 insertions(+), 18 deletions(-) diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index ff27d7a..b4ffad8 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -21,9 +21,13 @@ static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, int len = *max_len; int type; - if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) || - (connectable && len < BTRFS_FID_SIZE_CONNECTABLE)) + if (connectable && (len < BTRFS_FID_SIZE_CONNECTABLE)) { + *max_len = BTRFS_FID_SIZE_CONNECTABLE; return 255; + } else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) { + *max_len = BTRFS_FID_SIZE_NON_CONNECTABLE; + return 255; + } len = BTRFS_FID_SIZE_NON_CONNECTABLE; type = FILEID_BTRFS_WITHOUT_PARENT; diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 4b68257..cfe5573 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -320,9 +320,14 @@ static int export_encode_fh(struct dentry *dentry, struct fid *fid, struct inode * inode = dentry->d_inode; int len = *max_len; int type = FILEID_INO32_GEN; - - if (len < 2 || (connectable && len < 4)) + + if (connectable && (len < 4)) { + *max_len = 4; + return 255; + } else if (len < 2) { + *max_len = 2; return 255; + } len = 2; fid->i32.ino = inode->i_ino; diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 86753fe..0e277ec 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -757,8 +757,10 @@ fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable) struct inode *inode = de->d_inode; u32 ipos_h, ipos_m, ipos_l; - if (len < 5) + if (len < 5) { + *lenp = 5; return 255; /* no room */ + } ipos_h = MSDOS_I(inode)->i_pos >> 8; ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9e3f68c..051b1a0 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -637,8 +637,10 @@ static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, u64 nodeid; u32 generation; - if (*max_len < len) + if (*max_len < len) { + *max_len = len; return 255; + } nodeid = get_fuse_inode(inode)->nodeid; generation = inode->i_generation; diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index 9023db8..b5a5e60 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -36,9 +36,13 @@ static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len, struct super_block *sb = inode->i_sb; struct gfs2_inode *ip = GFS2_I(inode); - if (*len < GFS2_SMALL_FH_SIZE || - (connectable && *len < GFS2_LARGE_FH_SIZE)) + if (connectable && (*len < GFS2_LARGE_FH_SIZE)) { + *len = GFS2_LARGE_FH_SIZE; return 255; + } else if (*len < GFS2_SMALL_FH_SIZE) { + *len = GFS2_SMALL_FH_SIZE; + return 255; + } fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); diff --git a/fs/isofs/export.c b/fs/isofs/export.c index ed752cb..dd4687f 100644 --- a/fs/isofs/export.c +++ b/fs/isofs/export.c @@ -124,9 +124,13 @@ isofs_export_encode_fh(struct dentry *dentry, * offset of the inode and the upper 16 bits of fh32[1] to * hold the offset of the parent. */ - - if (len < 3 || (connectable && len < 5)) + if (connectable && (len < 5)) { + *max_len = 5; + return 255; + } else if (len < 3) { + *max_len = 3; return 255; + } len = 3; fh32[0] = ei->i_iget5_block; diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c index 5dbc306..254652a 100644 --- a/fs/ocfs2/export.c +++ b/fs/ocfs2/export.c @@ -197,8 +197,12 @@ static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len, dentry->d_name.len, dentry->d_name.name, fh, len, connectable); - if (len < 3 || (connectable && len < 6)) { - mlog(ML_ERROR, "fh buffer is too small for encoding\n"); + if (connectable && (len < 6)) { + *max_len = 6; + type = 255; + goto bail; + } else if (len < 3) { + *max_len = 3; type = 255; goto bail; } diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 0bae036..1bba24b 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -1593,8 +1593,13 @@ int reiserfs_encode_fh(struct dentry *dentry, __u32 * data, int *lenp, struct inode *inode = dentry->d_inode; int maxlen = *lenp; - if (maxlen < 3) + if (need_parent && (maxlen < 5)) { + *lenp = 5; return 255; + } else if (maxlen < 3) { + *lenp = 3; + return 255; + } data[0] = inode->i_ino; data[1] = le32_to_cpu(INODE_PKEY(inode)->k_dir_id); diff --git a/fs/udf/namei.c b/fs/udf/namei.c index b7c338d..f1dce84 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -1286,8 +1286,13 @@ static int udf_encode_fh(struct dentry *de, __u32 *fh, int *lenp, struct fid *fid = (struct fid *)fh; int type = FILEID_UDF_WITHOUT_PARENT; - if (len < 3 || (connectable && len < 5)) + if (connectable && (len < 5)) { + *lenp = 5; + return 255; + } else if (len < 3) { + *lenp = 3; return 255; + } *lenp = 3; fid->udf.block = location.logicalBlockNum; diff --git a/fs/xfs/linux-2.6/xfs_export.c b/fs/xfs/linux-2.6/xfs_export.c index fc0114d..f4f878f 100644 --- a/fs/xfs/linux-2.6/xfs_export.c +++ b/fs/xfs/linux-2.6/xfs_export.c @@ -89,8 +89,10 @@ xfs_fs_encode_fh( * seven combinations work. The real answer is "don't use v2". */ len = xfs_fileid_length(fileid_type); - if (*max_len < len) + if (*max_len < len) { + *max_len = len; return 255; + } *max_len = len; switch (fileid_type) { diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 2802898..65afdfd 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -121,8 +121,10 @@ struct fid { * set, the encode_fh() should store sufficient information so that a good * attempt can be made to find not only the file but also it's place in the * filesystem. This typically means storing a reference to de->d_parent in - * the filehandle fragment. encode_fh() should return the number of bytes - * stored or a negative error code such as %-ENOSPC + * the filehandle fragment. encode_fh() should return the fileid_type on + * success and on error returns 255 (if the space needed to encode fh is + * greater than @max_len*4 bytes). On error @max_len contains the minimum + * size(in 4 byte unit) needed to encode the file handle. * * fh_to_dentry: * @fh_to_dentry is given a &struct super_block (@sb) and a file handle diff --git a/mm/shmem.c b/mm/shmem.c index 5ee67c9..3437b65 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2144,8 +2144,10 @@ static int shmem_encode_fh(struct dentry *dentry, __u32 *fh, int *len, { struct inode *inode = dentry->d_inode; - if (*len < 3) + if (*len < 3) { + *len = 3; return 255; + } if (inode_unhashed(inode)) { /* Unfortunately insert_inode_hash is not idempotent, -- cgit v1.1