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author | Theodore Ts'o <tytso@mit.edu> | 2014-09-01 14:34:09 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2014-09-01 14:34:09 -0400 |
commit | 705912ca95f4bbdbb3be753e46bf30d6be15a5e8 (patch) | |
tree | 39b983f9ac9964104cf1475e31631b6dd554c728 /fs/ext4/move_extent.c | |
parent | bd30d702fc320085f178d22866b32fdc4736c991 (diff) | |
download | linux-stable-705912ca95f4bbdbb3be753e46bf30d6be15a5e8.tar.gz linux-stable-705912ca95f4bbdbb3be753e46bf30d6be15a5e8.tar.bz2 linux-stable-705912ca95f4bbdbb3be753e46bf30d6be15a5e8.zip |
ext4: teach ext4_ext_find_extent() to free path on error
Right now, there are a places where it is all to easy to leak memory
on an error path, via a usage like this:
struct ext4_ext_path *path = NULL
while (...) {
...
path = ext4_ext_find_extent(inode, block, path, 0);
if (IS_ERR(path)) {
/* oops, if path was non-NULL before the call to
ext4_ext_find_extent, we've leaked it! :-( */
...
return PTR_ERR(path);
}
...
}
Unfortunately, there some code paths where we are doing the following
instead:
path = ext4_ext_find_extent(inode, block, orig_path, 0);
and where it's important that we _not_ free orig_path in the case
where ext4_ext_find_extent() returns an error.
So change the function signature of ext4_ext_find_extent() so that it
takes a struct ext4_ext_path ** for its third argument, and by
default, on an error, it will free the struct ext4_ext_path, and then
zero out the struct ext4_ext_path * pointer. In order to avoid
causing problems, we add a flag EXT4_EX_NOFREE_ON_ERR which causes
ext4_ext_find_extent() to use the original behavior of forcing the
caller to deal with freeing the original path pointer on the error
case.
The goal is to get rid of EXT4_EX_NOFREE_ON_ERR entirely, but this
allows for a gentle transition and makes the patches easier to verify.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/move_extent.c')
-rw-r--r-- | fs/ext4/move_extent.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index c8f895b410f6..5e2465a8e4ce 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -37,7 +37,7 @@ get_ext_path(struct inode *inode, ext4_lblk_t lblock, int ret = 0; struct ext4_ext_path *path; - path = ext4_ext_find_extent(inode, lblock, *orig_path, EXT4_EX_NOCACHE); + path = ext4_ext_find_extent(inode, lblock, orig_path, EXT4_EX_NOCACHE); if (IS_ERR(path)) ret = PTR_ERR(path); else if (path[ext_depth(inode)].p_ext == NULL) |