From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
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 <linkinjeon@xxxxxxxxx>
Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
Signed-off-by: Ravishankar N <ravi.n1@xxxxxxxxxxx>
Signed-off-by: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
---
fs/fat/fat.h | 8 +--
fs/fat/file.c | 9 ++++
fs/fat/inode.c | 11 ++--
fs/fat/nfs.c | 126 ++++++++++++++++++++++++++++++++++++++++++++--
include/linux/exportfs.h | 11 ++++
5 files changed, 146 insertions(+), 19 deletions(-)
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 980c034..c517fc0 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 a62e0ec..de74655 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -306,6 +306,15 @@ 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) {
+ if (inode->i_ino == MSDOS_ROOT_INO)
+ stat->ino = MSDOS_ROOT_INO;
+ else
+ /* 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 8356a05..951e675 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -18,7 +18,6 @@
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/buffer_head.h>
-#include <linux/exportfs.h>
#include <linux/mount.h>
#include <linux/aio.h>
#include <linux/vfs.h>
@@ -749,12 +748,6 @@ 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);
@@ -1178,8 +1171,10 @@ 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;
}
diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c
index 499c104..bad8f46 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;
+} __packed;
+
+#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 +67,126 @@ 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 && (len < FAT_FID_SIZE_WITH_PARENT)) {
+ *lenp = FAT_FID_SIZE_WITH_PARENT;
+ return 255;
+ } else if (len < FAT_FID_SIZE_WITHOUT_PARENT) {
+ *lenp = FAT_FID_SIZE_WITHOUT_PARENT;
+ return 255;
+ }
+
+ 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 +201,16 @@ 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 5b9b5b3..41b223a 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -85,6 +85,17 @@ 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.
*/
FILEID_INVALID = 0xff,
--
1.7.9.5
--
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