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| author | Christian Brauner <brauner@kernel.org> | 2024-10-14 16:31:22 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-10-14 16:31:22 +0200 |
| commit | 58439f6c48a9dc7a12765a6b37a5c43a542ea90f (patch) | |
| tree | 7dc972388902272687e9f4ca69a6298a2d45d917 /fs/fs_parser.c | |
| parent | 8e929cb546ee42c9a61d24fae60605e9e3192354 (diff) | |
| parent | af9199145b1977316b3c752e2124543e320f087f (diff) | |
Merge patch series "ovl: file descriptors based layer setup"
Christian Brauner <brauner@kernel.org> says:
Currently overlayfs only allows specifying layers through path names.
This is inconvenient for users such as systemd that want to assemble an
overlayfs mount purely based on file descriptors.
When porting overlayfs to the new mount api I already mentioned this.
This enables user to specify both:
fsconfig(fd_overlay, FSCONFIG_SET_FD, "upperdir+", NULL, fd_upper);
fsconfig(fd_overlay, FSCONFIG_SET_FD, "workdir+", NULL, fd_work);
fsconfig(fd_overlay, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower1);
fsconfig(fd_overlay, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower2);
in addition to:
fsconfig(fd_overlay, FSCONFIG_SET_STRING, "upperdir+", "/upper", 0);
fsconfig(fd_overlay, FSCONFIG_SET_STRING, "workdir+", "/work", 0);
fsconfig(fd_overlay, FSCONFIG_SET_STRING, "lowerdir+", "/lower1", 0);
fsconfig(fd_overlay, FSCONFIG_SET_STRING, "lowerdir+", "/lower2", 0);
The selftest contain an example for this.
* patches from https://lore.kernel.org/r/20241014-work-overlayfs-v3-0-32b3fed1286e@kernel.org:
selftests: add overlayfs fd mounting selftests
selftests: use shared header
Documentation,ovl: document new file descriptor based layers
ovl: specify layers via file descriptors
fs: add helper to use mount option as path or fd
Link: https://lore.kernel.org/r/20241014-work-overlayfs-v3-0-32b3fed1286e@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/fs_parser.c')
| -rw-r--r-- | fs/fs_parser.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/fs_parser.c b/fs/fs_parser.c index 24727ec34e5a..8f583b814e6e 100644 --- a/fs/fs_parser.c +++ b/fs/fs_parser.c @@ -308,6 +308,26 @@ int fs_param_is_fd(struct p_log *log, const struct fs_parameter_spec *p, } EXPORT_SYMBOL(fs_param_is_fd); +int fs_param_is_file_or_string(struct p_log *log, + const struct fs_parameter_spec *p, + struct fs_parameter *param, + struct fs_parse_result *result) +{ + switch (param->type) { + case fs_value_is_string: + return fs_param_is_string(log, p, param, result); + case fs_value_is_file: + result->uint_32 = param->dirfd; + if (result->uint_32 <= INT_MAX) + return 0; + break; + default: + break; + } + return fs_param_bad_value(log, param); +} +EXPORT_SYMBOL(fs_param_is_file_or_string); + int fs_param_is_uid(struct p_log *log, const struct fs_parameter_spec *p, struct fs_parameter *param, struct fs_parse_result *result) { |