hfsplus: add per-superblock lock for volume header updates
Lock updates to the mutal fields in the volume header, and document the
locing in the hfsplus_sb_info structure.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index f8ae468..1c81eed 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -251,6 +251,7 @@
if (HFSPLUS_IS_RSRC(inode))
return -EPERM;
+ mutex_lock(&sbi->vh_mutex);
if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
for (;;) {
get_random_bytes(&id, sizeof(cnid));
@@ -263,7 +264,7 @@
if (!res)
break;
if (res != -EEXIST)
- return res;
+ goto out;
}
HFSPLUS_I(inode)->dev = id;
cnid = sbi->next_cnid++;
@@ -271,13 +272,13 @@
res = hfsplus_create_cat(cnid, src_dir, &src_dentry->d_name, inode);
if (res)
/* panic? */
- return res;
+ goto out;
sbi->file_count++;
}
cnid = sbi->next_cnid++;
res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
if (res)
- return res;
+ goto out;
inc_nlink(inode);
hfsplus_instantiate(dst_dentry, inode, cnid);
@@ -286,8 +287,9 @@
mark_inode_dirty(inode);
sbi->file_count++;
dst_dir->i_sb->s_dirt = 1;
-
- return 0;
+out:
+ mutex_unlock(&sbi->vh_mutex);
+ return res;
}
static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
@@ -302,6 +304,7 @@
if (HFSPLUS_IS_RSRC(inode))
return -EPERM;
+ mutex_lock(&sbi->vh_mutex);
cnid = (u32)(unsigned long)dentry->d_fsdata;
if (inode->i_ino == cnid &&
atomic_read(&HFSPLUS_I(inode)->opencnt)) {
@@ -312,11 +315,11 @@
sbi->hidden_dir, &str);
if (!res)
inode->i_flags |= S_DEAD;
- return res;
+ goto out;
}
res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
if (res)
- return res;
+ goto out;
if (inode->i_nlink > 0)
drop_nlink(inode);
@@ -339,37 +342,44 @@
sbi->file_count--;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
-
+out:
+ mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
{
- struct inode *inode;
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
+ struct inode *inode = dentry->d_inode;
int res;
- inode = dentry->d_inode;
if (inode->i_size != 2)
return -ENOTEMPTY;
+
+ mutex_lock(&sbi->vh_mutex);
res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
if (res)
- return res;
+ goto out;
clear_nlink(inode);
inode->i_ctime = CURRENT_TIME_SEC;
hfsplus_delete_inode(inode);
mark_inode_dirty(inode);
- return 0;
+out:
+ mutex_unlock(&sbi->vh_mutex);
+ return res;
}
static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
struct inode *inode;
- int res;
+ int res = -ENOSPC;
+ mutex_lock(&sbi->vh_mutex);
inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
if (!inode)
- return -ENOSPC;
+ goto out;
res = page_symlink(inode, symname, strlen(symname) + 1);
if (res)
@@ -381,31 +391,35 @@
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
- return 0;
+ goto out;
out_err:
inode->i_nlink = 0;
hfsplus_delete_inode(inode);
iput(inode);
+out:
+ mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
int mode, dev_t rdev)
{
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
struct inode *inode;
- int res;
+ int res = -ENOSPC;
+ mutex_lock(&sbi->vh_mutex);
inode = hfsplus_new_inode(dir->i_sb, mode);
if (!inode)
- return -ENOSPC;
+ goto out;
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (res) {
inode->i_nlink = 0;
hfsplus_delete_inode(inode);
iput(inode);
- return res;
+ goto out;
}
if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
@@ -413,7 +427,9 @@
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
- return 0;
+out:
+ mutex_unlock(&sbi->vh_mutex);
+ return res;
}
static int hfsplus_create(struct inode *dir, struct dentry *dentry, int mode,
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 0cd9ba0..08865ed 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -116,23 +116,26 @@
struct inode *hidden_dir;
struct nls_table *nls;
- /* synchronize block allocations */
- struct mutex alloc_mutex;
-
/* Runtime variables */
u32 blockoffset;
u32 sect_count;
int fs_shift;
- /* Stuff in host order from Vol Header */
+ /* immutable data from the volume header */
u32 alloc_blksz;
int alloc_blksz_shift;
u32 total_blocks;
+ u32 data_clump_blocks, rsrc_clump_blocks;
+
+ /* mutable data from the volume header, protected by alloc_mutex */
u32 free_blocks;
+ struct mutex alloc_mutex;
+
+ /* mutable data from the volume header, protected by vh_mutex */
u32 next_cnid;
u32 file_count;
u32 folder_count;
- u32 data_clump_blocks, rsrc_clump_blocks;
+ struct mutex vh_mutex;
/* Config options */
u32 creator;
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 923f385..b766c17 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -160,6 +160,7 @@
dprint(DBG_SUPER, "hfsplus_write_super\n");
+ mutex_lock(&sbi->vh_mutex);
mutex_lock(&sbi->alloc_mutex);
sb->s_dirt = 0;
@@ -194,6 +195,7 @@
sbi->flags &= ~HFSPLUS_SB_WRITEBACKUP;
}
mutex_unlock(&sbi->alloc_mutex);
+ mutex_unlock(&sbi->vh_mutex);
return 0;
}
@@ -319,6 +321,7 @@
sb->s_fs_info = sbi;
mutex_init(&sbi->alloc_mutex);
+ mutex_init(&sbi->vh_mutex);
hfsplus_fill_defaults(sbi);
if (!hfsplus_parse_options(data, sbi)) {
printk(KERN_ERR "hfs: unable to parse mount options\n");
@@ -453,9 +456,13 @@
if (!sbi->hidden_dir) {
printk(KERN_DEBUG "hfs: create hidden dir...\n");
+
+ mutex_lock(&sbi->vh_mutex);
sbi->hidden_dir = hfsplus_new_inode(sb, S_IFDIR);
hfsplus_create_cat(sbi->hidden_dir->i_ino, sb->s_root->d_inode,
&str, sbi->hidden_dir);
+ mutex_unlock(&sbi->vh_mutex);
+
mark_inode_dirty(sbi->hidden_dir);
}
out: