2.6.29-stable review patch. If anyone has any objections, please let us know.
--
From: Josef Bacik
commit df3935ffd6166fdd00702cf548fb5bb55737758b upstream.
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: Eric Sandeen
Signed-off-by: Josef Bacik
Cc:
Cc:
Cc:
Cc: Steven Whitehouse
Cc: Mark Fasheh
Cc: Joel Becker
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman
---
fs/ioctl.c | 75 -
1 file changed, 55 insertions(+), 20 deletions(-)
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -258,7 +258,7 @@ int __generic_block_fiemap(struct inode
long long length = 0, map_len = 0;
u64 logical = 0, phys = 0, size = 0;
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)))
return ret;
@@ -266,6 +266,9 @@ int __generic_block_fiemap(struct inode
start_blk = logical_to_blk(inode, start);
length = (long long)min_t(u64, len, i_size_read(inode));
+ if (length < len)
+ whole_file = 1;
+
map_len = length;
do {
@@ -282,11 +285,26 @@ int __generic_block_fiemap(struct inode
/* HOLE */
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
* last extent
*/
- if (length <= 0) {
+ if (past_eof && size) {
flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
ret = fiemap_fill_next_extent(fieinfo, logical,
phys, size,
@@ -294,15 +312,37 @@ int __generic_block_fiemap(struct inode
break;
}
- length -= blk_to_logical(inode, 1);
-
/* if we have holes up to/past EOF then we're done */
- if (length <= 0)
+ if (length <= 0 || past_eof)
break;
-
- start_blk++;
} 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,
