Messages in this thread Patch in this message | | | From | NeilBrown <> | Date | Mon, 31 Oct 2005 17:34:44 +1100 | Subject | [PATCH against 2.6.14] truncate() or ftruncate shouldn't change mtime if size doesn't change. |
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According to Posix and SUS, truncate(2) and ftruncate(2) only update ctime and mtime if the size actually changes. Linux doesn't currently obey this.
There is no need to test the size under i_sem, as loosing any race will not make a noticable different the mtime or ctime.
(According to SUS, truncate and ftruncate 'may' clear setuid/setgid as well, currently we don't. Should we? )
Signed-off-by: Neil Brown <neilb@suse.de>
### Diffstat output ./fs/open.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff ./fs/open.c~current~ ./fs/open.c --- ./fs/open.c~current~ 2005-10-31 16:22:44.000000000 +1100 +++ ./fs/open.c 2005-10-31 16:22:44.000000000 +1100 @@ -260,7 +260,8 @@ static inline long do_sys_truncate(const goto dput_and_out; error = locks_verify_truncate(inode, NULL, length); - if (!error) { + if (!error && + length != i_size_read(dentry->d_inode)) { DQUOT_INIT(inode); error = do_truncate(nd.dentry, length); } @@ -313,7 +314,8 @@ static inline long do_sys_ftruncate(unsi goto out_putf; error = locks_verify_truncate(inode, file, length); - if (!error) + if (!error && + length != i_size_read(dentry->d_inode)) error = do_truncate(dentry, length); out_putf: fput(file); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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