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Merge 24e16e385f ("ovl: add support for appending lowerdirs one by one") into android-mainline

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Steps on the way to 6.7-rc1

Change-Id: Ie9eacc88192aafcfe21e15720836ee8f2ce06c08
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman
2024-01-10 10:23:03 +00:00
parent 5c16e0ef86 24e16e385f
commit 15bc93eb84
2 changed files with 90 additions and 5 deletions
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Documentation/filesystems/overlayfs.rst
+14 -3
View File
@@ -368,10 +368,11 @@ escaping the colons with a single backslash. For example:
mount -t overlay overlay -olowerdir=/a\:lower\:\:dir /merged
Since kernel version v6.5, directory names containing colons can also
be provided as lower layer using the fsconfig syscall from new mount api:
Since kernel version v6.8, directory names containing colons can also
be configured as lower layer using the "lowerdir+" mount options and the
fsconfig syscall from new mount api. For example:
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", "/a:lower::dir", 0);
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir+", "/a:lower::dir", 0);
In the latter case, colons in lower layer directory names will be escaped
as an octal characters (\072) when displayed in /proc/self/mountinfo.
@@ -440,6 +441,16 @@ Only the data of the files in the "data-only" lower layers may be visible
when a "metacopy" file in one of the lower layers above it, has a "redirect"
to the absolute path of the "lower data" file in the "data-only" lower layer.
Since kernel version v6.8, "data-only" lower layers can also be added using
the "datadir+" mount options and the fsconfig syscall from new mount api.
For example:
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir+", "/l1", 0);
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir+", "/l2", 0);
fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir+", "/l3", 0);
fsconfig(fs_fd, FSCONFIG_SET_STRING, "datadir+", "/do1", 0);
fsconfig(fs_fd, FSCONFIG_SET_STRING, "datadir+", "/do2", 0);
fs-verity support
----------------------
fs/overlayfs/params.c
+76 -2
View File
@@ -50,6 +50,8 @@ MODULE_PARM_DESC(ovl_override_creds_def,
enum ovl_opt {
Opt_lowerdir,
Opt_lowerdir_add,
Opt_datadir_add,
Opt_upperdir,
Opt_workdir,
Opt_default_permissions,
@@ -146,8 +148,11 @@ static int ovl_verity_mode_def(void)
#define fsparam_string_empty(NAME, OPT) \
__fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
const struct fs_parameter_spec ovl_parameter_spec[] = {
fsparam_string_empty("lowerdir", Opt_lowerdir),
fsparam_string("lowerdir+", Opt_lowerdir_add),
fsparam_string("datadir+", Opt_datadir_add),
fsparam_string("upperdir", Opt_upperdir),
fsparam_string("workdir", Opt_workdir),
fsparam_flag("default_permissions", Opt_default_permissions),
@@ -280,12 +285,15 @@ static int ovl_mount_dir(const char *name, struct path *path)
static int ovl_mount_dir_check(struct fs_context *fc, const struct path *path,
enum ovl_opt layer, const char *name, bool upper)
{
struct ovl_fs_context *ctx = fc->fs_private;
if (ovl_dentry_weird(path->dentry))
return invalfc(fc, "filesystem on %s not supported", name);
if (!d_is_dir(path->dentry))
return invalfc(fc, "%s is not a directory", name);
/*
* Check whether upper path is read-only here to report failures
* early. Don't forget to recheck when the superblock is created
@@ -296,16 +304,45 @@ static int ovl_mount_dir_check(struct fs_context *fc, const struct path *path,
return invalfc(fc, "filesystem on %s not supported as upperdir", name);
if (__mnt_is_readonly(path->mnt))
return invalfc(fc, "filesystem on %s is read-only", name);
} else {
if (ctx->lowerdir_all && layer != Opt_lowerdir)
return invalfc(fc, "lowerdir+ and datadir+ cannot follow lowerdir");
if (ctx->nr_data && layer == Opt_lowerdir_add)
return invalfc(fc, "regular lower layers cannot follow data layers");
if (ctx->nr == OVL_MAX_STACK)
return invalfc(fc, "too many lower directories, limit is %d",
OVL_MAX_STACK);
}
return 0;
}
static int ovl_ctx_realloc_lower(struct fs_context *fc)
{
struct ovl_fs_context *ctx = fc->fs_private;
struct ovl_fs_context_layer *l;
size_t nr;
if (ctx->nr < ctx->capacity)
return 0;
nr = min_t(size_t, max(4096 / sizeof(*l), ctx->capacity * 2),
OVL_MAX_STACK);
l = krealloc_array(ctx->lower, nr, sizeof(*l), GFP_KERNEL_ACCOUNT);
if (!l)
return -ENOMEM;
ctx->lower = l;
ctx->capacity = nr;
return 0;
}
static void ovl_add_layer(struct fs_context *fc, enum ovl_opt layer,
struct path *path, char **pname)
{
struct ovl_fs *ofs = fc->s_fs_info;
struct ovl_config *config = &ofs->config;
struct ovl_fs_context *ctx = fc->fs_private;
struct ovl_fs_context_layer *l;
switch (layer) {
case Opt_workdir:
@@ -316,6 +353,16 @@ static void ovl_add_layer(struct fs_context *fc, enum ovl_opt layer,
swap(config->upperdir, *pname);
swap(ctx->upper, *path);
break;
case Opt_datadir_add:
ctx->nr_data++;
fallthrough;
case Opt_lowerdir_add:
WARN_ON(ctx->nr >= ctx->capacity);
l = &ctx->lower[ctx->nr++];
memset(l, 0, sizeof(*l));
swap(l->name, *pname);
swap(l->path, *path);
break;
default:
WARN_ON(1);
}
@@ -332,7 +379,10 @@ static int ovl_parse_layer(struct fs_context *fc, struct fs_parameter *param,
if (!name)
return -ENOMEM;
err = ovl_mount_dir(name, &path);
if (upper)
err = ovl_mount_dir(name, &path);
else
err = ovl_mount_dir_noesc(name, &path);
if (err)
goto out_free;
@@ -340,6 +390,12 @@ static int ovl_parse_layer(struct fs_context *fc, struct fs_parameter *param,
if (err)
goto out_put;
if (!upper) {
err = ovl_ctx_realloc_lower(fc);
if (err)
goto out_put;
}
/* Store the user provided path string in ctx to show in mountinfo */
ovl_add_layer(fc, layer, &path, &name);
@@ -526,6 +582,8 @@ static int ovl_parse_param(struct fs_context *fc, struct fs_parameter *param)
case Opt_lowerdir:
err = ovl_parse_param_lowerdir(param->string, fc);
break;
case Opt_lowerdir_add:
case Opt_datadir_add:
case Opt_upperdir:
case Opt_workdir:
err = ovl_parse_layer(fc, param, opt);
@@ -904,13 +962,29 @@ int ovl_show_options(struct seq_file *m, struct dentry *dentry)
{
struct super_block *sb = dentry->d_sb;
struct ovl_fs *ofs = OVL_FS(sb);
size_t nr, nr_merged_lower, nr_lower = 0;
char **lowerdirs = ofs->config.lowerdirs;
/*
* lowerdirs[0] holds the colon separated list that user provided
* with lowerdir mount option.
* lowerdirs[1..numlayer] hold the lowerdir paths that were added
* using the lowerdir+ and datadir+ mount options.
* For now, we do not allow mixing the legacy lowerdir mount option
* with the new lowerdir+ and datadir+ mount options.
*/
seq_show_option(m, "lowerdir", lowerdirs[0]);
if (lowerdirs[0]) {
seq_show_option(m, "lowerdir", lowerdirs[0]);
} else {
nr_lower = ofs->numlayer;
nr_merged_lower = nr_lower - ofs->numdatalayer;
}
for (nr = 1; nr < nr_lower; nr++) {
if (nr < nr_merged_lower)
seq_show_option(m, "lowerdir+", lowerdirs[nr]);
else
seq_show_option(m, "datadir+", lowerdirs[nr]);
}
if (ofs->config.upperdir) {
seq_show_option(m, "upperdir", ofs->config.upperdir);
seq_show_option(m, "workdir", ofs->config.workdir);