From: Amir Goldstein amir73il@gmail.com
[ Upstream commit c835110b588a750650988ca5000913c3c60d246b ]
Commit beae836e9c61 ("ovl: temporarily disable appending lowedirs") removed the ability to append lowerdirs with syntax lowerdir=":<path>". Remove leftover code and comments that are irrelevant with lowerdir append mode disabled.
Signed-off-by: Amir Goldstein amir73il@gmail.com Stable-dep-of: 2824083db76c ("ovl: Always reject mounting over case-insensitive directories") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/overlayfs/params.c | 95 ++++++++----------------------------------- 1 file changed, 16 insertions(+), 79 deletions(-)
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c index f6ff23fd101c8..0059cc405159e 100644 --- a/fs/overlayfs/params.c +++ b/fs/overlayfs/params.c @@ -346,7 +346,7 @@ static void ovl_parse_param_drop_lowerdir(struct ovl_fs_context *ctx) /* * Parse lowerdir= mount option: * - * (1) lowerdir=/lower1:/lower2:/lower3::/data1::/data2 + * e.g.: lowerdir=/lower1:/lower2:/lower3::/data1::/data2 * Set "/lower1", "/lower2", and "/lower3" as lower layers and * "/data1" and "/data2" as data lower layers. Any existing lower * layers are replaced. @@ -356,9 +356,9 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) int err; struct ovl_fs_context *ctx = fc->fs_private; struct ovl_fs_context_layer *l; - char *dup = NULL, *dup_iter; + char *dup = NULL, *iter; ssize_t nr_lower = 0, nr = 0, nr_data = 0; - bool append = false, data_layer = false; + bool data_layer = false;
/* * Ensure we're backwards compatible with mount(2) @@ -366,10 +366,10 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) */
/* drop all existing lower layers */ - if (!*name) { - ovl_parse_param_drop_lowerdir(ctx); + ovl_parse_param_drop_lowerdir(ctx); + + if (!*name) return 0; - }
if (*name == ':') { pr_err("cannot append lower layer"); @@ -385,36 +385,11 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) if (nr_lower < 0) goto out_err;
- if ((nr_lower > OVL_MAX_STACK) || - (append && (size_add(ctx->nr, nr_lower) > OVL_MAX_STACK))) { + if (nr_lower > OVL_MAX_STACK) { pr_err("too many lower directories, limit is %d\n", OVL_MAX_STACK); goto out_err; }
- if (!append) - ovl_parse_param_drop_lowerdir(ctx); - - /* - * (1) append - * - * We want nr <= nr_lower <= capacity We know nr > 0 and nr <= - * capacity. If nr == 0 this wouldn't be append. If nr + - * nr_lower is <= capacity then nr <= nr_lower <= capacity - * already holds. If nr + nr_lower exceeds capacity, we realloc. - * - * (2) replace - * - * Ensure we're backwards compatible with mount(2) which allows - * "lowerdir=/a:/b:/c,lowerdir=/d:/e:/f" causing the last - * specified lowerdir mount option to win. - * - * We want nr <= nr_lower <= capacity We know either (i) nr == 0 - * or (ii) nr > 0. We also know nr_lower > 0. The capacity - * could've been changed multiple times already so we only know - * nr <= capacity. If nr + nr_lower > capacity we realloc, - * otherwise nr <= nr_lower <= capacity holds already. - */ - nr_lower += ctx->nr; if (nr_lower > ctx->capacity) { err = -ENOMEM; l = krealloc_array(ctx->lower, nr_lower, sizeof(*ctx->lower), @@ -426,41 +401,17 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) ctx->capacity = nr_lower; }
- /* - * (3) By (1) and (2) we know nr <= nr_lower <= capacity. - * (4) If ctx->nr == 0 => replace - * We have verified above that the lowerdir mount option - * isn't an append, i.e., the lowerdir mount option - * doesn't start with ":" or "::". - * (4.1) The lowerdir mount options only contains regular lower - * layers ":". - * => Nothing to verify. - * (4.2) The lowerdir mount options contains regular ":" and - * data "::" layers. - * => We need to verify that data lower layers "::" aren't - * followed by regular ":" lower layers - * (5) If ctx->nr > 0 => append - * We know that there's at least one regular layer - * otherwise we would've failed when parsing the previous - * lowerdir mount option. - * (5.1) The lowerdir mount option is a regular layer ":" append - * => We need to verify that no data layers have been - * specified before. - * (5.2) The lowerdir mount option is a data layer "::" append - * We know that there's at least one regular layer or - * other data layers. => There's nothing to verify. - */ - dup_iter = dup; - for (nr = ctx->nr; nr < nr_lower; nr++) { - l = &ctx->lower[nr]; + iter = dup; + l = ctx->lower; + for (nr = 0; nr < nr_lower; nr++, l++) { memset(l, 0, sizeof(*l));
- err = ovl_mount_dir(dup_iter, &l->path, false); + err = ovl_mount_dir(iter, &l->path, false); if (err) goto out_put;
err = -ENOMEM; - l->name = kstrdup(dup_iter, GFP_KERNEL_ACCOUNT); + l->name = kstrdup(iter, GFP_KERNEL_ACCOUNT); if (!l->name) goto out_put;
@@ -472,8 +423,8 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) break;
err = -EINVAL; - dup_iter = strchr(dup_iter, '\0') + 1; - if (*dup_iter) { + iter = strchr(iter, '\0') + 1; + if (*iter) { /* * This is a regular layer so we require that * there are no data layers. @@ -489,7 +440,7 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc)
/* This is a data lower layer. */ data_layer = true; - dup_iter++; + iter++; } ctx->nr = nr_lower; ctx->nr_data += nr_data; @@ -497,21 +448,7 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) return 0;
out_put: - /* - * We know nr >= ctx->nr < nr_lower. If we failed somewhere - * we want to undo until nr == ctx->nr. This is correct for - * both ctx->nr == 0 and ctx->nr > 0. - */ - for (; nr >= ctx->nr; nr--) { - l = &ctx->lower[nr]; - kfree(l->name); - l->name = NULL; - path_put(&l->path); - - /* don't overflow */ - if (nr == 0) - break; - } + ovl_parse_param_drop_lowerdir(ctx);
out_err: kfree(dup);