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 <namjae.jeon@samsung.com>
Signed-off-by: Ravishankar N <ravi.n1@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c
index 499c104..d59c025 100644
--- a/fs/fat/nfs.c
+++ b/fs/fat/nfs.c
@@ -14,6 +14,18 @@
#include <linux/exportfs.h>
#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 @@
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 @@
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 @@
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,
+};