| Support the MS_NOSYMFOLLOW mount flag. Added to Chrome OS in 5.4 and sent |
| upstream as: |
| |
| https://lore.kernel.org/linux-fsdevel/20200304173446.122990-1-zwisler@google.com/ |
| |
| See b/152074038 for background. |
| |
| diff --git a/libmount/src/context_mount.c b/libmount/src/context_mount.c |
| index 088d1328e..5cce46556 100644 |
| --- a/libmount/src/context_mount.c |
| +++ b/libmount/src/context_mount.c |
| @@ -422,6 +422,8 @@ static int generate_helper_optstr(struct libmnt_context *cxt, char **optstr) |
| mnt_optstr_append_option(optstr, "suid", NULL); |
| if (!(cxt->mountflags & MS_NODEV)) |
| mnt_optstr_append_option(optstr, "dev", NULL); |
| + if (!(cxt->mountflags & MS_NOSYMFOLLOW)) |
| + mnt_optstr_append_option(optstr, "symfollow", NULL); |
| } |
| |
| |
| diff --git a/libmount/src/libmount.h.in b/libmount/src/libmount.h.in |
| index 321c0540b..e6710ae01 100644 |
| --- a/libmount/src/libmount.h.in |
| +++ b/libmount/src/libmount.h.in |
| @@ -941,6 +941,9 @@ extern int mnt_context_set_syscall_status(struct libmnt_context *cxt, int status |
| #ifndef MS_DIRSYNC |
| #define MS_DIRSYNC 128 /* Directory modifications are synchronous */ |
| #endif |
| +#ifndef MS_NOSYMFOLLOW |
| +#define MS_NOSYMFOLLOW 256 /* Don't follow symlinks */ |
| +#endif |
| #ifndef MS_NOATIME |
| #define MS_NOATIME 0x400 /* 1024: Do not update access times. */ |
| #endif |
| diff --git a/libmount/src/optmap.c b/libmount/src/optmap.c |
| index abd81bc8e..731771327 100644 |
| --- a/libmount/src/optmap.c |
| +++ b/libmount/src/optmap.c |
| @@ -131,6 +131,10 @@ static const struct libmnt_optmap linux_flags_map[] = |
| { "rslave", MS_SLAVE | MS_REC, MNT_NOHLPS | MNT_NOMTAB }, |
| { "shared", MS_SHARED, MNT_NOHLPS | MNT_NOMTAB }, /* Shared */ |
| { "rshared", MS_SHARED | MS_REC, MNT_NOHLPS | MNT_NOMTAB }, |
| +#endif |
| +#ifdef MS_NOSYMFOLLOW |
| + { "symfollow", MS_NOSYMFOLLOW, MNT_INVERT }, /* Don't follow symlinks */ |
| + { "nosymfollow", MS_NOSYMFOLLOW }, |
| #endif |
| { NULL, 0, 0 } |
| }; |
