diff options
Diffstat (limited to 'fs/ioctl.c')
| -rw-r--r-- | fs/ioctl.c | 44 |
1 files changed, 34 insertions, 10 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c index 43e8b2c0664..cc3f1aa1cf7 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -231,7 +231,8 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg) #define blk_to_logical(inode, blk) (blk << (inode)->i_blkbits) #define logical_to_blk(inode, offset) (offset >> (inode)->i_blkbits); -/* +/** + * __generic_block_fiemap - FIEMAP for block based inodes (no locking) * @inode - the inode to map * @arg - the pointer to userspace where we copy everything to * @get_block - the fs's get_block function @@ -242,11 +243,15 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg) * * If it is possible to have data blocks beyond a hole past @inode->i_size, then * please do not use this function, it will stop at the first unmapped block - * beyond i_size + * beyond i_size. + * + * If you use this function directly, you need to do your own locking. Use + * generic_block_fiemap if you want the locking done for you. */ -int generic_block_fiemap(struct inode *inode, - struct fiemap_extent_info *fieinfo, u64 start, - u64 len, get_block_t *get_block) + +int __generic_block_fiemap(struct inode *inode, + struct fiemap_extent_info *fieinfo, u64 start, + u64 len, get_block_t *get_block) { struct buffer_head tmp; unsigned int start_blk; @@ -260,9 +265,6 @@ int generic_block_fiemap(struct inode *inode, start_blk = logical_to_blk(inode, start); - /* guard against change */ - mutex_lock(&inode->i_mutex); - length = (long long)min_t(u64, len, i_size_read(inode)); map_len = length; @@ -334,14 +336,36 @@ int generic_block_fiemap(struct inode *inode, cond_resched(); } while (1); - mutex_unlock(&inode->i_mutex); - /* if ret is 1 then we just hit the end of the extent array */ if (ret == 1) ret = 0; return ret; } +EXPORT_SYMBOL(__generic_block_fiemap); + +/** + * generic_block_fiemap - FIEMAP for block based inodes + * @inode: The inode to map + * @fieinfo: The mapping information + * @start: The initial block to map + * @len: The length of the extect to attempt to map + * @get_block: The block mapping function for the fs + * + * Calls __generic_block_fiemap to map the inode, after taking + * the inode's mutex lock. + */ + +int generic_block_fiemap(struct inode *inode, + struct fiemap_extent_info *fieinfo, u64 start, + u64 len, get_block_t *get_block) +{ + int ret; + mutex_lock(&inode->i_mutex); + ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block); + mutex_unlock(&inode->i_mutex); + return ret; +} EXPORT_SYMBOL(generic_block_fiemap); #endif /* CONFIG_BLOCK */ |