hfsplus: introduce alloc_mutex

Use a new per-sb alloc_mutex instead of abusing i_mutex of the alloc_file
to protect block allocations.  This gets rid of lockdep nesting warnings
and prepares for extending the scope of alloc_mutex.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>

diff --git a/fs/hfsplus/bitmap.c b/fs/hfsplus/bitmap.c
index ea30afc2a03c774221cc17341c446d30a0cb341b..8a781769a901a48208b685ecf68ee9286d89d708 100644 (file)
--- a/fs/hfsplus/bitmap.c
+++ b/fs/hfsplus/bitmap.c
@@ -29,7 +29,7 @@ int hfsplus_block_allocate(struct super_block *sb, u32 size, u32 offset, u32 *ma
                return size;
 
        dprint(DBG_BITMAP, "block_allocate: %u,%u,%u\n", size, offset, len);
-       mutex_lock(&HFSPLUS_SB(sb).alloc_file->i_mutex);
+       mutex_lock(&HFSPLUS_SB(sb).alloc_mutex);
        mapping = HFSPLUS_SB(sb).alloc_file->i_mapping;
        page = read_mapping_page(mapping, offset / PAGE_CACHE_BITS, NULL);
        if (IS_ERR(page)) {
@@ -154,7 +154,7 @@ done:
        sb->s_dirt = 1;
        dprint(DBG_BITMAP, "-> %u,%u\n", start, *max);
 out:
-       mutex_unlock(&HFSPLUS_SB(sb).alloc_file->i_mutex);
+       mutex_unlock(&HFSPLUS_SB(sb).alloc_mutex);
        return start;
 }
 
@@ -175,7 +175,7 @@ int hfsplus_block_free(struct super_block *sb, u32 offset, u32 count)
        if ((offset + count) > HFSPLUS_SB(sb).total_blocks)
                return -2;
 
-       mutex_lock(&HFSPLUS_SB(sb).alloc_file->i_mutex);
+       mutex_lock(&HFSPLUS_SB(sb).alloc_mutex);
        mapping = HFSPLUS_SB(sb).alloc_file->i_mapping;
        pnr = offset / PAGE_CACHE_BITS;
        page = read_mapping_page(mapping, pnr, NULL);
@@ -226,7 +226,7 @@ out:
        kunmap(page);
        HFSPLUS_SB(sb).free_blocks += len;
        sb->s_dirt = 1;
-       mutex_unlock(&HFSPLUS_SB(sb).alloc_file->i_mutex);
+       mutex_unlock(&HFSPLUS_SB(sb).alloc_mutex);
 
        return 0;
 }

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index dc856be3c2b010854c78da1049b86d2f7ce48147..df0a6312f0f09a7e77a4d0487613b676422a5d04 100644 (file)
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -116,6 +116,9 @@ struct hfsplus_sb_info {
        struct inode *hidden_dir;
        struct nls_table *nls;
 
+       /* synchronize block allocations */
+       struct mutex alloc_mutex;
+
        /* Runtime variables */
        u32 blockoffset;
        u32 sect_count;

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 3b55c050c74274710fa95cad827edf6abd6b8316..3dc62aa58728331cd78d883f95288394dcea2086 100644 (file)
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -321,6 +321,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 
        sb->s_fs_info = sbi;
        INIT_HLIST_HEAD(&sbi->rsrc_inodes);
+       mutex_init(&sbi->alloc_mutex);
        hfsplus_fill_defaults(sbi);
        if (!hfsplus_parse_options(data, sbi)) {
                printk(KERN_ERR "hfs: unable to parse mount options\n");