From fada5391b35db9065849ebcdabf3065af3ded90b Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Wed, 27 Mar 2013 10:25:49 +1100 Subject: [PATCH] fat: restructure export_operations Define two nfs export_operation structures,one for 'stale_rw' mounts and the other for 'nostale_ro'. The latter uses i_pos as a basis for encoding and decoding file handles. Also, assign i_pos to kstat->ino. The logic for rebuilding the inode is added in the subsequent patches. Signed-off-by: Namjae Jeon Signed-off-by: Ravishankar N Signed-off-by: Amit Sahrawat Acked-by: OGAWA Hirofumi Signed-off-by: Andrew Morton --- fs/fat/fat.h | 8 +-- fs/fat/file.c | 5 ++ fs/fat/inode.c | 13 ++-- fs/fat/nfs.c | 130 +++++++++++++++++++++++++++++++++++++-- include/linux/exportfs.h | 11 ++++ 5 files changed, 147 insertions(+), 20 deletions(-) diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 980c0346c168..c517fc066cf7 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -406,12 +406,8 @@ int fat_cache_init(void); void fat_cache_destroy(void); /* fat/nfs.c */ -struct fid; -extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, - int fh_len, int fh_type); -extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, - int fh_len, int fh_type); -extern struct dentry *fat_get_parent(struct dentry *child_dir); +extern const struct export_operations fat_export_ops; +extern const struct export_operations fat_export_ops_nostale; /* helper for printk */ typedef unsigned long long llu; diff --git a/fs/fat/file.c b/fs/fat/file.c index 3978f8ca1823..b0b632e50ddb 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -306,6 +306,11 @@ int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) struct inode *inode = dentry->d_inode; generic_fillattr(inode, stat); stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size; + + if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) { + /* Use i_pos for ino. This is used as fileid of nfs. */ + stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode); + } return 0; } EXPORT_SYMBOL_GPL(fat_getattr); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 68cb5a6eb539..27f49f4fa0d3 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -18,7 +18,6 @@ #include #include #include -#include #include #include #include @@ -748,12 +747,6 @@ static const struct super_operations fat_sops = { .show_options = fat_show_options, }; -static const struct export_operations fat_export_ops = { - .fh_to_dentry = fat_fh_to_dentry, - .fh_to_parent = fat_fh_to_parent, - .get_parent = fat_get_parent, -}; - static int fat_show_options(struct seq_file *m, struct dentry *root) { struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); @@ -1177,8 +1170,10 @@ out: opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); if (opts->unicode_xlate) opts->utf8 = 0; - if (opts->nfs == FAT_NFS_NOSTALE_RO) + if (opts->nfs == FAT_NFS_NOSTALE_RO) { sb->s_flags |= MS_RDONLY; + sb->s_export_op = &fat_export_ops_nostale; + } return 0; } @@ -1189,7 +1184,7 @@ static int fat_read_root(struct inode *inode) struct msdos_sb_info *sbi = MSDOS_SB(sb); int error; - MSDOS_I(inode)->i_pos = 0; + MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; inode->i_uid = sbi->options.fs_uid; inode->i_gid = sbi->options.fs_gid; inode->i_version++; diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c index 499c10438ca2..d59c02543a10 100644 --- a/fs/fat/nfs.c +++ b/fs/fat/nfs.c @@ -14,6 +14,18 @@ #include #include "fat.h" +struct fat_fid { + u32 i_gen; + u32 i_pos_low; + u16 i_pos_hi; + u16 parent_i_pos_hi; + u32 parent_i_pos_low; + u32 parent_i_gen; +}; + +#define FAT_FID_SIZE_WITHOUT_PARENT 3 +#define FAT_FID_SIZE_WITH_PARENT (sizeof(struct fat_fid)/sizeof(u32)) + /** * Look up a directory inode given its starting cluster. */ @@ -38,8 +50,8 @@ static struct inode *fat_dget(struct super_block *sb, int i_logstart) return inode; } -static struct inode *fat_nfs_get_inode(struct super_block *sb, - u64 ino, u32 generation) +static struct inode *__fat_nfs_get_inode(struct super_block *sb, + u64 ino, u32 generation, loff_t i_pos) { struct inode *inode; @@ -55,35 +67,130 @@ static struct inode *fat_nfs_get_inode(struct super_block *sb, return inode; } +static struct inode *fat_nfs_get_inode(struct super_block *sb, + u64 ino, u32 generation) +{ + + return __fat_nfs_get_inode(sb, ino, generation, 0); +} + +static int +fat_encode_fh_nostale(struct inode *inode, __u32 *fh, int *lenp, + struct inode *parent) +{ + int len = *lenp; + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + struct fat_fid *fid = (struct fat_fid *) fh; + loff_t i_pos; + int type = FILEID_FAT_WITHOUT_PARENT; + + if (parent) { + if (len < FAT_FID_SIZE_WITH_PARENT) { + *lenp = FAT_FID_SIZE_WITH_PARENT; + return FILEID_INVALID; + } + } else { + if (len < FAT_FID_SIZE_WITHOUT_PARENT) { + *lenp = FAT_FID_SIZE_WITHOUT_PARENT; + return FILEID_INVALID; + } + } + + i_pos = fat_i_pos_read(sbi, inode); + *lenp = FAT_FID_SIZE_WITHOUT_PARENT; + fid->i_gen = inode->i_generation; + fid->i_pos_low = i_pos & 0xFFFFFFFF; + fid->i_pos_hi = (i_pos >> 32) & 0xFFFF; + if (parent) { + i_pos = fat_i_pos_read(sbi, parent); + fid->parent_i_pos_hi = (i_pos >> 32) & 0xFFFF; + fid->parent_i_pos_low = i_pos & 0xFFFFFFFF; + fid->parent_i_gen = parent->i_generation; + type = FILEID_FAT_WITH_PARENT; + *lenp = FAT_FID_SIZE_WITH_PARENT; + } + + return type; +} + /** * Map a NFS file handle to a corresponding dentry. * The dentry may or may not be connected to the filesystem root. */ -struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, +static struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { return generic_fh_to_dentry(sb, fid, fh_len, fh_type, fat_nfs_get_inode); } +static struct dentry *fat_fh_to_dentry_nostale(struct super_block *sb, + struct fid *fh, int fh_len, + int fh_type) +{ + struct inode *inode = NULL; + struct fat_fid *fid = (struct fat_fid *)fh; + loff_t i_pos; + + switch (fh_type) { + case FILEID_FAT_WITHOUT_PARENT: + if (fh_len < FAT_FID_SIZE_WITHOUT_PARENT) + return NULL; + break; + case FILEID_FAT_WITH_PARENT: + if (fh_len < FAT_FID_SIZE_WITH_PARENT) + return NULL; + break; + default: + return NULL; + } + i_pos = fid->i_pos_hi; + i_pos = (i_pos << 32) | (fid->i_pos_low); + inode = __fat_nfs_get_inode(sb, 0, fid->i_gen, i_pos); + + return d_obtain_alias(inode); +} + /* * Find the parent for a file specified by NFS handle. * This requires that the handle contain the i_ino of the parent. */ -struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, +static struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { return generic_fh_to_parent(sb, fid, fh_len, fh_type, fat_nfs_get_inode); } +static struct dentry *fat_fh_to_parent_nostale(struct super_block *sb, + struct fid *fh, int fh_len, + int fh_type) +{ + struct inode *inode = NULL; + struct fat_fid *fid = (struct fat_fid *)fh; + loff_t i_pos; + + if (fh_len < FAT_FID_SIZE_WITH_PARENT) + return NULL; + + switch (fh_type) { + case FILEID_FAT_WITH_PARENT: + i_pos = fid->parent_i_pos_hi; + i_pos = (i_pos << 32) | (fid->parent_i_pos_low); + inode = __fat_nfs_get_inode(sb, 0, fid->parent_i_gen, i_pos); + break; + } + + return d_obtain_alias(inode); +} + /* * Find the parent for a directory that is not currently connected to * the filesystem root. * * On entry, the caller holds child_dir->d_inode->i_mutex. */ -struct dentry *fat_get_parent(struct dentry *child_dir) +static struct dentry *fat_get_parent(struct dentry *child_dir) { struct super_block *sb = child_dir->d_sb; struct buffer_head *bh = NULL; @@ -98,3 +205,16 @@ struct dentry *fat_get_parent(struct dentry *child_dir) return d_obtain_alias(parent_inode); } + +const struct export_operations fat_export_ops = { + .fh_to_dentry = fat_fh_to_dentry, + .fh_to_parent = fat_fh_to_parent, + .get_parent = fat_get_parent, +}; + +const struct export_operations fat_export_ops_nostale = { + .encode_fh = fat_encode_fh_nostale, + .fh_to_dentry = fat_fh_to_dentry_nostale, + .fh_to_parent = fat_fh_to_parent_nostale, + .get_parent = fat_get_parent, +}; diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 5b9b5b317180..41b223a59a63 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -84,6 +84,17 @@ enum fid_type { */ FILEID_NILFS_WITH_PARENT = 0x62, + /* + * 32 bit generation number, 40 bit i_pos. + */ + FILEID_FAT_WITHOUT_PARENT = 0x71, + + /* + * 32 bit generation number, 40 bit i_pos, + * 32 bit parent generation number, 40 bit parent i_pos + */ + FILEID_FAT_WITH_PARENT = 0x72, + /* * Filesystems must not use 0xff file ID. */ -- 2.39.5