diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ioctl.c | 92 |
1 files changed, 53 insertions, 39 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c index 6c751106c2e..7faefb4da93 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -228,14 +228,23 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg) #ifdef CONFIG_BLOCK -#define blk_to_logical(inode, blk) (blk << (inode)->i_blkbits) -#define logical_to_blk(inode, offset) (offset >> (inode)->i_blkbits); +static inline sector_t logical_to_blk(struct inode *inode, loff_t offset) +{ + return (offset >> inode->i_blkbits); +} + +static inline loff_t blk_to_logical(struct inode *inode, sector_t blk) +{ + return (blk << 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 + * @inode: the inode to map + * @fieinfo: the fiemap info struct that will be passed back to userspace + * @start: where to start mapping in the inode + * @len: how much space to map + * @get_block: the fs's get_block function * * This does FIEMAP for block based inodes. Basically it will just loop * through get_block until we hit the number of extents we want to map, or we @@ -250,58 +259,63 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg) */ int __generic_block_fiemap(struct inode *inode, - struct fiemap_extent_info *fieinfo, u64 start, - u64 len, get_block_t *get_block) + struct fiemap_extent_info *fieinfo, loff_t start, + loff_t len, get_block_t *get_block) { - struct buffer_head tmp; - unsigned long long start_blk; - long long length = 0, map_len = 0; + struct buffer_head map_bh; + sector_t start_blk, last_blk; + loff_t isize = i_size_read(inode); u64 logical = 0, phys = 0, size = 0; u32 flags = FIEMAP_EXTENT_MERGED; - int ret = 0, past_eof = 0, whole_file = 0; + bool past_eof = false, whole_file = false; + int ret = 0; - if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC))) + ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); + if (ret) return ret; - start_blk = logical_to_blk(inode, start); - - length = (long long)min_t(u64, len, i_size_read(inode)); - if (length < len) - whole_file = 1; + /* + * Either the i_mutex or other appropriate locking needs to be held + * since we expect isize to not change at all through the duration of + * this call. + */ + if (len >= isize) { + whole_file = true; + len = isize; + } - map_len = length; + start_blk = logical_to_blk(inode, start); + last_blk = logical_to_blk(inode, start + len - 1); do { /* * we set b_size to the total size we want so it will map as * many contiguous blocks as possible at once */ - memset(&tmp, 0, sizeof(struct buffer_head)); - tmp.b_size = map_len; + memset(&map_bh, 0, sizeof(struct buffer_head)); + map_bh.b_size = len; - ret = get_block(inode, start_blk, &tmp, 0); + ret = get_block(inode, start_blk, &map_bh, 0); if (ret) break; /* HOLE */ - if (!buffer_mapped(&tmp)) { - length -= blk_to_logical(inode, 1); + if (!buffer_mapped(&map_bh)) { start_blk++; /* - * we want to handle the case where there is an + * We want to handle the case where there is an * allocated block at the front of the file, and then * nothing but holes up to the end of the file properly, * to make sure that extent at the front gets properly * marked with FIEMAP_EXTENT_LAST */ if (!past_eof && - blk_to_logical(inode, start_blk) >= - blk_to_logical(inode, 0)+i_size_read(inode)) + blk_to_logical(inode, start_blk) >= isize) past_eof = 1; /* - * first hole after going past the EOF, this is our + * First hole after going past the EOF, this is our * last extent */ if (past_eof && size) { @@ -309,15 +323,18 @@ int __generic_block_fiemap(struct inode *inode, ret = fiemap_fill_next_extent(fieinfo, logical, phys, size, flags); - break; + } else if (size) { + ret = fiemap_fill_next_extent(fieinfo, logical, + phys, size, flags); + size = 0; } /* if we have holes up to/past EOF then we're done */ - if (length <= 0 || past_eof) + if (start_blk > last_blk || past_eof || ret) break; } else { /* - * we have gone over the length of what we wanted to + * We have gone over the length of what we wanted to * map, and it wasn't the entire file, so add the extent * we got last time and exit. * @@ -331,7 +348,7 @@ int __generic_block_fiemap(struct inode *inode, * are good to go, just add the extent to the fieinfo * and break */ - if (length <= 0 && !whole_file) { + if (start_blk > last_blk && !whole_file) { ret = fiemap_fill_next_extent(fieinfo, logical, phys, size, flags); @@ -351,11 +368,10 @@ int __generic_block_fiemap(struct inode *inode, } logical = blk_to_logical(inode, start_blk); - phys = blk_to_logical(inode, tmp.b_blocknr); - size = tmp.b_size; + phys = blk_to_logical(inode, map_bh.b_blocknr); + size = map_bh.b_size; flags = FIEMAP_EXTENT_MERGED; - length -= tmp.b_size; start_blk += logical_to_blk(inode, size); /* @@ -363,15 +379,13 @@ int __generic_block_fiemap(struct inode *inode, * soon as we find a hole that the last extent we found * is marked with FIEMAP_EXTENT_LAST */ - if (!past_eof && - logical+size >= - blk_to_logical(inode, 0)+i_size_read(inode)) - past_eof = 1; + if (!past_eof && logical + size >= isize) + past_eof = true; } cond_resched(); } while (1); - /* if ret is 1 then we just hit the end of the extent array */ + /* If ret is 1 then we just hit the end of the extent array */ if (ret == 1) ret = 0; |