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author | Miklos Szeredi <mszeredi@suse.cz> | 2014-10-24 00:14:37 +0200 |
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committer | Miklos Szeredi <mszeredi@suse.cz> | 2014-10-24 00:14:37 +0200 |
commit | 0d7a855526dd672e114aff2ac22b60fc6f155b08 (patch) | |
tree | 5354ed84bddf7ca55c6cdd3509a71fd8e0bcf63e | |
parent | 787fb6bc9682ec7c05fb5d9561b57100fbc1cc41 (diff) | |
download | linux-0d7a855526dd672e114aff2ac22b60fc6f155b08.tar.gz linux-0d7a855526dd672e114aff2ac22b60fc6f155b08.tar.bz2 linux-0d7a855526dd672e114aff2ac22b60fc6f155b08.zip |
vfs: add RENAME_WHITEOUT
This adds a new RENAME_WHITEOUT flag. This flag makes rename() create a
whiteout of source. The whiteout creation is atomic relative to the
rename.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
-rw-r--r-- | fs/namei.c | 8 | ||||
-rw-r--r-- | include/uapi/linux/fs.h | 1 |
2 files changed, 7 insertions, 2 deletions
diff --git a/fs/namei.c b/fs/namei.c index d20191c0ebf5..42df664e95e5 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4209,12 +4209,16 @@ SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, bool should_retry = false; int error; - if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) return -EINVAL; - if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE)) + if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) && + (flags & RENAME_EXCHANGE)) return -EINVAL; + if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD)) + return -EPERM; + retry: from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags); if (IS_ERR(from)) { diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index ca1a11bb4443..3735fa0a6784 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -37,6 +37,7 @@ #define RENAME_NOREPLACE (1 << 0) /* Don't overwrite target */ #define RENAME_EXCHANGE (1 << 1) /* Exchange source and dest */ +#define RENAME_WHITEOUT (1 << 2) /* Whiteout source */ struct fstrim_range { __u64 start; |