Commit 8fceb4e0 authored by Namjae Jeon's avatar Namjae Jeon Committed by Linus Torvalds

fat (exportfs): rebuild inode if ilookup() fails

If the cache lookups fail,use the i_pos value to find the directory entry
of the inode and rebuild the inode.Since this involves accessing the FAT
media, do this only if the nostale_ro nfs mount option is specified.
Signed-off-by: default avatarNamjae Jeon <>
Signed-off-by: default avatarRavishankar N <>
Signed-off-by: default avatarAmit Sahrawat <>
Acked-by: default avatarOGAWA Hirofumi <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent ea3983ac
......@@ -75,6 +75,7 @@ struct msdos_sb_info {
unsigned long root_cluster; /* first cluster of the root directory */
unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
struct mutex fat_lock;
struct mutex nfs_build_inode_lock;
struct mutex s_lock;
unsigned int prev_free; /* previously allocated cluster number */
unsigned int free_clusters; /* -1 if undefined */
......@@ -443,12 +443,25 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
return 0;
static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
struct inode *fat_build_inode(struct super_block *sb,
struct msdos_dir_entry *de, loff_t i_pos)
struct inode *inode;
int err;
inode = fat_iget(sb, i_pos);
if (inode)
goto out;
......@@ -468,6 +481,7 @@ struct inode *fat_build_inode(struct super_block *sb,
fat_attach(inode, i_pos);
return inode;
......@@ -1247,6 +1261,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
sb->s_magic = MSDOS_SUPER_MAGIC;
sb->s_op = &fat_sops;
sb->s_export_op = &fat_export_ops;
ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
......@@ -50,19 +50,50 @@ static struct inode *fat_dget(struct super_block *sb, int i_logstart)
return inode;
static struct inode *fat_ilookup(struct super_block *sb, u64 ino, loff_t i_pos)
if (MSDOS_SB(sb)->options.nfs == FAT_NFS_NOSTALE_RO)
return fat_iget(sb, i_pos);
else {
if ((ino < MSDOS_ROOT_INO) || (ino == MSDOS_FSINFO_INO))
return NULL;
return ilookup(sb, ino);
static struct inode *__fat_nfs_get_inode(struct super_block *sb,
u64 ino, u32 generation, loff_t i_pos)
struct inode *inode;
if ((ino < MSDOS_ROOT_INO) || (ino == MSDOS_FSINFO_INO))
return NULL;
struct inode *inode = fat_ilookup(sb, ino, i_pos);
inode = ilookup(sb, ino);
if (inode && generation && (inode->i_generation != generation)) {
inode = NULL;
if (inode == NULL && MSDOS_SB(sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
struct buffer_head *bh = NULL;
struct msdos_dir_entry *de ;
sector_t blocknr;
int offset;
fat_get_blknr_offset(MSDOS_SB(sb), i_pos, &blocknr, &offset);
bh = sb_bread(sb, blocknr);
if (!bh) {
fat_msg(sb, KERN_ERR,
"unable to read block(%llu) for building NFS inode",
return inode;
de = (struct msdos_dir_entry *)bh->b_data;
/* If a file is deleted on server and client is not updated
* yet, we must not build the inode upon a lookup call.
if (IS_FREE(de[offset].name))
inode = NULL;
inode = fat_build_inode(sb, &de[offset], i_pos);
return inode;
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