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Message-Id: <1346774312-8142-1-git-send-email-linkinjeon@gmail.com>
Date: Wed, 5 Sep 2012 00:58:32 +0900
From: Namjae Jeon <linkinjeon@...il.com>
To: hirofumi@...l.parknet.co.jp, akpm@...ux-foundation.org,
bfields@...ldses.org, viro@...iv.linux.org.uk
Cc: linux-kernel@...r.kernel.org, Namjae Jeon <linkinjeon@...il.com>,
Namjae Jeon <namjae.jeon@...sung.com>,
Ravishankar N <ravi.n1@...sung.com>,
Amit Sahrawat <a.sahrawat@...sung.com>
Subject: [PATCH v2 4/5] fat: eliminate orphaned inode number allocation
From: Namjae Jeon <namjae.jeon@...sung.com>
Maintain a list of inode(i_pos) numbers of orphaned inodes (i.e the
inodes that have been unlinked but still having open file
descriptors).At file/directory creation time, skip using such i_pos
values.Removal of the i_pos from the list is done during inode eviction.
Signed-off-by: Namjae Jeon <namjae.jeon@...sung.com>
Signed-off-by: Ravishankar N <ravi.n1@...sung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@...sung.com>
---
fs/fat/dir.c | 4 +++
fs/fat/fat.h | 11 ++++++++
fs/fat/inode.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
fs/fat/namei_vfat.c | 25 ++++++++++++++++-
4 files changed, 116 insertions(+), 1 deletion(-)
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 7b1b9c1..e24fe5e 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -1268,7 +1268,10 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
if (pos >= FAT_MAX_DIR_SIZE)
goto error;
+
if (IS_FREE(de->name)) {
+ if (sbi->options.nfs && fat_entry_busy(sbi, pos, bh))
+ goto free;
if (prev != bh) {
get_bh(bh);
bhs[nr_bhs] = prev = bh;
@@ -1278,6 +1281,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
if (free_slots == nr_slots)
goto found;
} else {
+free:
for (i = 0; i < nr_bhs; i++)
brelse(bhs[i]);
prev = NULL;
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 88b6c29..9a53783 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -93,6 +93,9 @@ struct msdos_sb_info {
spinlock_t dir_hash_lock;
struct hlist_head dir_hashtable[FAT_HASH_SIZE];
+
+ spinlock_t ipos_busy_lock;
+ struct list_head *ipos_list_head;
};
#define FAT_CACHE_VALID 0 /* special case for valid cache */
@@ -128,6 +131,12 @@ struct fat_slot_info {
struct buffer_head *bh;
};
+struct ipos_busy_list {
+ struct list_head ipos_list;
+ loff_t i_pos; /* on disk position for busy directory entry */
+ int nr_slots;
+};
+
static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
{
return sb->s_fs_info;
@@ -341,6 +350,8 @@ extern void fat_detach(struct inode *inode);
extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
extern struct inode *fat_build_inode(struct super_block *sb,
struct msdos_dir_entry *de, loff_t i_pos);
+extern int fat_entry_busy(struct msdos_sb_info *sbi, loff_t ipos,
+ struct buffer_head *bh);
extern int fat_sync_inode(struct inode *inode);
extern int fat_fill_super(struct super_block *sb, void *data, int silent,
int isvfat, void (*setup)(struct super_block *));
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 0811339..47ff899 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -291,6 +291,23 @@ static void dir_hash_init(struct super_block *sb)
INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
}
+static int ipos_list_init(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+ sbi->ipos_list_head = kzalloc(sizeof(struct ipos_busy_list),
+ GFP_KERNEL);
+ if (!sbi->ipos_list_head) {
+ fat_msg(sb, KERN_ERR,
+ "Failed to allocate memory for ipos list head");
+ return -ENOMEM;
+ }
+ spin_lock_init(&sbi->ipos_busy_lock);
+ INIT_LIST_HEAD(sbi->ipos_list_head);
+
+ return 0;
+}
+
void fat_attach(struct inode *inode, loff_t i_pos)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
@@ -477,8 +494,64 @@ out:
EXPORT_SYMBOL_GPL(fat_build_inode);
+int fat_entry_busy(struct msdos_sb_info *sbi, loff_t ipos,
+ struct buffer_head *bh)
+{
+ struct list_head *pos, *q;
+ struct ipos_busy_list *plist;
+ int offset;
+ loff_t curpos;
+
+ if (list_empty(sbi->ipos_list_head))
+ return 0;
+
+ offset = (ipos - sizeof(struct msdos_dir_entry)) >> MSDOS_DIR_BITS;
+ curpos = ((bh->b_blocknr) << sbi->dir_per_block_bits) | offset;
+
+ spin_lock(&sbi->ipos_busy_lock);
+ list_for_each_safe(pos, q, sbi->ipos_list_head) {
+ plist = list_entry(pos, struct ipos_busy_list, ipos_list);
+ if (plist) {
+ if ((curpos > (plist->i_pos - plist->nr_slots)) &&
+ (curpos <= plist->i_pos)) {
+ spin_unlock(&sbi->ipos_busy_lock);
+ return 1;
+ }
+ }
+ }
+ spin_unlock(&sbi->ipos_busy_lock);
+ return 0;
+}
+
+static void fat_remove_busy_entry(struct inode *inode)
+{
+
+ struct super_block *sb = inode->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct list_head *pos, *q;
+ struct ipos_busy_list *plist;
+
+ spin_lock(&sbi->ipos_busy_lock);
+ list_for_each_safe(pos, q, sbi->ipos_list_head) {
+ plist = list_entry(pos, struct ipos_busy_list,
+ ipos_list);
+ if (plist) {
+ if (plist->i_pos == MSDOS_I(inode)->i_pos) {
+ list_del(pos);
+ kfree(plist);
+ break;
+ }
+ }
+ }
+ spin_unlock(&sbi->ipos_busy_lock);
+
+}
+
static void fat_evict_inode(struct inode *inode)
{
+
+ if (MSDOS_SB(inode->i_sb)->options.nfs)
+ fat_remove_busy_entry(inode);
truncate_inode_pages(&inode->i_data, 0);
if (!inode->i_nlink) {
inode->i_size = 0;
@@ -504,6 +577,8 @@ static void fat_put_super(struct super_block *sb)
kfree(sbi->options.iocharset);
sb->s_fs_info = NULL;
+ if (sbi->options.nfs)
+ kfree(sbi->ipos_list_head);
kfree(sbi);
}
@@ -1367,6 +1442,8 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
fat_hash_init(sb);
dir_hash_init(sb);
fat_ent_access_init(sb);
+ if (sbi->options.nfs && ipos_list_init(sb) < 0)
+ goto out_fail;
/*
* The low byte of FAT's first entry must have same value with
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 00d58ea..01020b7 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -834,6 +834,26 @@ out:
return err;
}
+static void fat_add_busy_entry(struct super_block *sb, struct inode *inode,
+ struct fat_slot_info sinfo)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct ipos_busy_list *unlinked_ipos = NULL;
+
+ if (inode && (atomic_read(&inode->i_count))) {
+ unlinked_ipos = kzalloc(sizeof(struct ipos_busy_list),
+ GFP_KERNEL);
+ if (unlinked_ipos) {
+ unlinked_ipos->i_pos = sinfo.i_pos;
+ unlinked_ipos->nr_slots = sinfo.nr_slots;
+ spin_lock(&sbi->ipos_busy_lock);
+ list_add_tail(&unlinked_ipos->ipos_list,
+ sbi->ipos_list_head);
+ spin_unlock(&sbi->ipos_busy_lock);
+ }
+ }
+}
+
static int vfat_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
@@ -852,7 +872,10 @@ static int vfat_unlink(struct inode *dir, struct dentry *dentry)
goto out;
clear_nlink(inode);
inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
- fat_detach(inode);
+ if (MSDOS_SB(sb)->options.nfs)
+ fat_add_busy_entry(sb, inode, sinfo);
+ else
+ fat_detach(inode);
out:
unlock_super(sb);
--
1.7.9.5
--
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