fs: introduce SB_INLINECRYPT

Introduce SB_INLINECRYPT, which is set by filesystems that wish to use
blk-crypto for file content en/decryption. This flag maps to the
'-o inlinecrypt' mount option which multiple filesystems will implement,
and code in fs/crypto/ needs to be able to check for this mount option
in a filesystem-independent way.

Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200702015607.1215430-2-satyat@google.com
Signed-off-by: Eric Biggers <ebiggers@google.com>

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3f881a892ea7469278ef799f44254a8f809ffd3f..b5e07fcdd11df9228bf63cd24042f2dbce705145 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1380,6 +1380,7 @@ extern int send_sigurg(struct fown_struct *fown);
 #define SB_NODIRATIME  2048    /* Do not update directory access times */
 #define SB_SILENT      32768
 #define SB_POSIXACL    (1<<16) /* VFS does not apply the umask */
+#define SB_INLINECRYPT (1<<17) /* Use blk-crypto for encrypted files */
 #define SB_KERNMOUNT   (1<<22) /* this is a kern_mount call */
 #define SB_I_VERSION   (1<<23) /* Update inode I_version field */
 #define SB_LAZYTIME    (1<<25) /* Update the on-disk [acm]times lazily */