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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-21 23:20:46 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-21 23:20:46 +0300 |
commit | e9f57ebcba563e0cd532926cab83c92bb4d79360 (patch) | |
tree | 6cf11baa7851129145cc35f9218583287f41dd64 /fs/overlayfs/super.c | |
parent | 5c89e9ea7ef1feaa147325b2ab47a89a147fb903 (diff) | |
parent | 84889d49335627bc770b32787c1ef9ebad1da232 (diff) | |
download | linux-e9f57ebcba563e0cd532926cab83c92bb4d79360.tar.xz |
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
"This contains several bug fixes and a new mount option
'default_permissions' that allows read-only exported NFS
filesystems to be used as lower layer"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: check dentry positiveness in ovl_cleanup_whiteouts()
ovl: setattr: check permissions before copy-up
ovl: root: copy attr
ovl: move super block magic number to magic.h
ovl: use a minimal buffer in ovl_copy_xattr
ovl: allow zero size xattr
ovl: default permissions
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r-- | fs/overlayfs/super.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index e38ee0fed24a..a4cbdf9824c7 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -9,6 +9,7 @@ #include <linux/fs.h> #include <linux/namei.h> +#include <linux/pagemap.h> #include <linux/xattr.h> #include <linux/security.h> #include <linux/mount.h> @@ -24,12 +25,11 @@ MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); MODULE_DESCRIPTION("Overlay filesystem"); MODULE_LICENSE("GPL"); -#define OVERLAYFS_SUPER_MAGIC 0x794c7630 - struct ovl_config { char *lowerdir; char *upperdir; char *workdir; + bool default_permissions; }; /* private information held for overlayfs's superblock */ @@ -154,6 +154,18 @@ struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper) return realdentry; } +struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode, + bool is_upper) +{ + if (is_upper) { + struct ovl_fs *ofs = inode->i_sb->s_fs_info; + + return ofs->upper_mnt; + } else { + return oe->numlower ? oe->lowerstack[0].mnt : NULL; + } +} + struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) { struct ovl_entry *oe = dentry->d_fsdata; @@ -161,6 +173,13 @@ struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) return oe->cache; } +bool ovl_is_default_permissions(struct inode *inode) +{ + struct ovl_fs *ofs = inode->i_sb->s_fs_info; + + return ofs->config.default_permissions; +} + void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache) { struct ovl_entry *oe = dentry->d_fsdata; @@ -594,6 +613,8 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) seq_show_option(m, "upperdir", ufs->config.upperdir); seq_show_option(m, "workdir", ufs->config.workdir); } + if (ufs->config.default_permissions) + seq_puts(m, ",default_permissions"); return 0; } @@ -618,6 +639,7 @@ enum { OPT_LOWERDIR, OPT_UPPERDIR, OPT_WORKDIR, + OPT_DEFAULT_PERMISSIONS, OPT_ERR, }; @@ -625,6 +647,7 @@ static const match_table_t ovl_tokens = { {OPT_LOWERDIR, "lowerdir=%s"}, {OPT_UPPERDIR, "upperdir=%s"}, {OPT_WORKDIR, "workdir=%s"}, + {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, {OPT_ERR, NULL} }; @@ -685,6 +708,10 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) return -ENOMEM; break; + case OPT_DEFAULT_PERMISSIONS: + config->default_permissions = true; + break; + default: pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p); return -EINVAL; @@ -910,6 +937,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) } sb->s_stack_depth = 0; + sb->s_maxbytes = MAX_LFS_FILESIZE; if (ufs->config.upperdir) { if (!ufs->config.workdir) { pr_err("overlayfs: missing 'workdir'\n"); @@ -1053,6 +1081,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) root_dentry->d_fsdata = oe; + ovl_copyattr(ovl_dentry_real(root_dentry)->d_inode, + root_dentry->d_inode); + sb->s_magic = OVERLAYFS_SUPER_MAGIC; sb->s_op = &ovl_super_operations; sb->s_root = root_dentry; |