From 8fceb4e0171f6bf64db756c65b2ce5f15aed8b4d Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Mon, 29 Apr 2013 16:21:12 -0700 Subject: [PATCH] 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: Namjae Jeon Signed-off-by: Ravishankar N Signed-off-by: Amit Sahrawat Acked-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/fat.h | 1 + fs/fat/inode.c | 15 +++++++++++++++ fs/fat/nfs.c | 41 ++++++++++++++++++++++++++++++++++++----- 3 files changed, 52 insertions(+), 5 deletions(-) diff --git a/fs/fat/fat.h b/fs/fat/fat.h index c517fc066cf7..413eaaf30ed5 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -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 */ diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 27f49f4fa0d3..971ba7d549da 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -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) + mutex_lock(&sbi->nfs_build_inode_lock); +} + +static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) +{ + if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) + mutex_unlock(&sbi->nfs_build_inode_lock); +} + struct inode *fat_build_inode(struct super_block *sb, struct msdos_dir_entry *de, loff_t i_pos) { struct inode *inode; int err; + fat_lock_build_inode(MSDOS_SB(sb)); 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); insert_inode_hash(inode); out: + fat_unlock_build_inode(MSDOS_SB(sb)); 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; + mutex_init(&sbi->nfs_build_inode_lock); ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c index d59c02543a10..0748196889b2 100644 --- a/fs/fat/nfs.c +++ b/fs/fat/nfs.c @@ -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)) { iput(inode); 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", + (llu)blocknr); + 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; + else + inode = fat_build_inode(sb, &de[offset], i_pos); + brelse(bh); + } return inode; } -- 2.39.2