From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
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 <namjae.jeon@xxxxxxxxxxx>
Signed-off-by: Ravishankar N <ravi.n1@xxxxxxxxxxx>
Signed-off-by: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
---
fs/fat/fat.h | 1 +
fs/fat/inode.c | 15 +++++++++++++++
fs/fat/nfs.c | 40 +++++++++++++++++++++++++++++++++++-----
3 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 40ceb79..bbad32c 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 3127c0b..62e0ad5 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -444,12 +444,25 @@ 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;
@@ -469,6 +482,7 @@ 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;
}
@@ -1188,6 +1202,7 @@ 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 6ea1d41..898bef4 100644
--- a/fs/fat/nfs.c
+++ b/fs/fat/nfs.c
@@ -52,19 +52,49 @@ 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;
}
--
1.7.9.5
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