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| author | Christoph Hellwig <hch@infradead.org> | 2011-06-24 14:29:40 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-07-20 20:47:44 -0400 |
| commit | 582686915803e34adc8fdcd90bff7ca7f6a42221 (patch) | |
| tree | 5a522cb6dbc41eaac987dbf15a2cbae35b2544cc | |
| parent | 8c5dc70aae29d2571c0f461d69b37e4e6e01ff4c (diff) | |
| download | linux-stable-582686915803e34adc8fdcd90bff7ca7f6a42221.tar.gz linux-stable-582686915803e34adc8fdcd90bff7ca7f6a42221.tar.bz2 linux-stable-582686915803e34adc8fdcd90bff7ca7f6a42221.zip | |
fat: remove i_alloc_sem abuse
Add a new rw_semaphore to protect bmap against truncate. Previous
i_alloc_sem was abused for this, but it's going away in this series.
Note that we can't simply use i_mutex, given that the swapon code
calls ->bmap under it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/fat/fat.h | 1 | ||||
| -rw-r--r-- | fs/fat/file.c | 2 | ||||
| -rw-r--r-- | fs/fat/inode.c | 6 |
3 files changed, 7 insertions, 2 deletions
diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 8276cc282dec..a975b4147e91 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -109,6 +109,7 @@ struct msdos_inode_info { int i_attrs; /* unused attribute bits */ loff_t i_pos; /* on-disk position of directory entry or 0 */ struct hlist_node i_fat_hash; /* hash by i_location */ + struct rw_semaphore truncate_lock; /* protect bmap against truncate */ struct inode vfs_inode; }; diff --git a/fs/fat/file.c b/fs/fat/file.c index 7018e1d8902d..a4a3a3c06436 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -429,8 +429,10 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) } if (attr->ia_valid & ATTR_SIZE) { + down_write(&MSDOS_I(inode)->truncate_lock); truncate_setsize(inode, attr->ia_size); fat_truncate_blocks(inode, attr->ia_size); + up_write(&MSDOS_I(inode)->truncate_lock); } setattr_copy(inode, attr); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index cb8d8391ac0b..3decce46c38f 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -224,9 +224,9 @@ static sector_t _fat_bmap(struct address_space *mapping, sector_t block) sector_t blocknr; /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ - down_read(&mapping->host->i_alloc_sem); + down_read(&MSDOS_I(mapping->host)->truncate_lock); blocknr = generic_block_bmap(mapping, block, fat_get_block); - up_read(&mapping->host->i_alloc_sem); + up_read(&MSDOS_I(mapping->host)->truncate_lock); return blocknr; } @@ -510,6 +510,8 @@ static struct inode *fat_alloc_inode(struct super_block *sb) ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); if (!ei) return NULL; + + init_rwsem(&ei->truncate_lock); return &ei->vfs_inode; } |