Commit df3935ff authored by Josef Bacik's avatar Josef Bacik Committed by Linus Torvalds

fiemap: fix problem with setting FIEMAP_EXTENT_LAST

Fix a problem where the generic block based fiemap stuff would not
properly set FIEMAP_EXTENT_LAST on the last extent.  I've reworked things
to keep track if we go past the EOF, and mark the last extent properly.
The problem was reported by and tested by Eric Sandeen.
Tested-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatarJosef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: <xfs-masters@oss.sgi.com>
Cc: <linux-btrfs@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <Joel.Becker@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 57adc4d2
...@@ -258,7 +258,7 @@ int __generic_block_fiemap(struct inode *inode, ...@@ -258,7 +258,7 @@ int __generic_block_fiemap(struct inode *inode,
long long length = 0, map_len = 0; long long length = 0, map_len = 0;
u64 logical = 0, phys = 0, size = 0; u64 logical = 0, phys = 0, size = 0;
u32 flags = FIEMAP_EXTENT_MERGED; u32 flags = FIEMAP_EXTENT_MERGED;
int ret = 0; int ret = 0, past_eof = 0, whole_file = 0;
if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC))) if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC)))
return ret; return ret;
...@@ -266,6 +266,9 @@ int __generic_block_fiemap(struct inode *inode, ...@@ -266,6 +266,9 @@ int __generic_block_fiemap(struct inode *inode,
start_blk = logical_to_blk(inode, start); start_blk = logical_to_blk(inode, start);
length = (long long)min_t(u64, len, i_size_read(inode)); length = (long long)min_t(u64, len, i_size_read(inode));
if (length < len)
whole_file = 1;
map_len = length; map_len = length;
do { do {
...@@ -282,11 +285,26 @@ int __generic_block_fiemap(struct inode *inode, ...@@ -282,11 +285,26 @@ int __generic_block_fiemap(struct inode *inode,
/* HOLE */ /* HOLE */
if (!buffer_mapped(&tmp)) { if (!buffer_mapped(&tmp)) {
length -= blk_to_logical(inode, 1);
start_blk++;
/*
* 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))
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 * last extent
*/ */
if (length <= 0) { if (past_eof && size) {
flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST; flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
ret = fiemap_fill_next_extent(fieinfo, logical, ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size, phys, size,
...@@ -294,15 +312,37 @@ int __generic_block_fiemap(struct inode *inode, ...@@ -294,15 +312,37 @@ int __generic_block_fiemap(struct inode *inode,
break; break;
} }
length -= blk_to_logical(inode, 1);
/* if we have holes up to/past EOF then we're done */ /* if we have holes up to/past EOF then we're done */
if (length <= 0) if (length <= 0 || past_eof)
break; break;
start_blk++;
} else { } else {
if (length <= 0 && size) { /*
* 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.
*
* This is for the case where say we want to map all the
* way up to the second to the last block in a file, but
* the last block is a hole, making the second to last
* block FIEMAP_EXTENT_LAST. In this case we want to
* see if there is a hole after the second to last block
* so we can mark it properly. If we found data after
* we exceeded the length we were requesting, then we
* are good to go, just add the extent to the fieinfo
* and break
*/
if (length <= 0 && !whole_file) {
ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size,
flags);
break;
}
/*
* if size != 0 then we know we already have an extent
* to add, so add it.
*/
if (size) {
ret = fiemap_fill_next_extent(fieinfo, logical, ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size, phys, size,
flags); flags);
...@@ -319,19 +359,14 @@ int __generic_block_fiemap(struct inode *inode, ...@@ -319,19 +359,14 @@ int __generic_block_fiemap(struct inode *inode,
start_blk += logical_to_blk(inode, size); start_blk += logical_to_blk(inode, size);
/* /*
* if we are past the EOF we need to loop again to see * If we are past the EOF, then we need to make sure as
* if there is a hole so we can mark this extent as the * soon as we find a hole that the last extent we found
* last one, and if not keep mapping things until we * is marked with FIEMAP_EXTENT_LAST
* find a hole, or we run out of slots in the extent
* array
*/ */
if (length <= 0) if (!past_eof &&
continue; logical+size >=
blk_to_logical(inode, 0)+i_size_read(inode))
ret = fiemap_fill_next_extent(fieinfo, logical, phys, past_eof = 1;
size, flags);
if (ret)
break;
} }
cond_resched(); cond_resched();
} while (1); } while (1);
......
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