Commit 0f831ec8 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: simplify ovl_same_sb() helper 



No code uses the sb returned from this helper, so make it retrun a boolean
and rename it to ovl_same_fs().

The xino mode is irrelevant when all layers are on same fs, so instead of
describing samefs with mode OVL_XINO_OFF, use a new xino_mode state, which
is 0 in the case of samefs, -1 in the case of xino=off and > 0 with xino
enabled.

Create a new helper ovl_same_dev(), to use instead of the common check for
(ovl_same_fs() || xinobits).

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 94375f9d

fs/overlayfs/inode.c

+4 −4
Original line number Diff line number Diff line
@@ -78,7 +78,7 @@ out: 
static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat,

			   struct ovl_layer *lower_layer)

{

	bool samefs = ovl_same_sb(dentry->d_sb);

	bool samefs = ovl_same_fs(dentry->d_sb);

	unsigned int xinobits = ovl_xino_bits(dentry->d_sb);



	if (samefs) {
@@ -146,7 +146,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, 
	struct path realpath;

	const struct cred *old_cred;

	bool is_dir = S_ISDIR(dentry->d_inode->i_mode);

	bool samefs = ovl_same_sb(dentry->d_sb);

	bool samefs = ovl_same_fs(dentry->d_sb);

	struct ovl_layer *lower_layer = NULL;

	int err;

	bool metacopy_blocks = false;
@@ -168,7 +168,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, 
	 * If lower filesystem supports NFS file handles, this also guaranties

	 * persistent st_ino across mount cycle.

	 */

	if (!is_dir || samefs || ovl_xino_bits(dentry->d_sb)) {

	if (!is_dir || ovl_same_dev(dentry->d_sb)) {

		if (!OVL_TYPE_UPPER(type)) {

			lower_layer = ovl_layer_lower(dentry);

		} else if (OVL_TYPE_ORIGIN(type)) {
@@ -586,7 +586,7 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev, 
	 * ovl_new_inode(), ino arg is 0, so i_ino will be updated to real

	 * upper inode i_ino on ovl_inode_init() or ovl_inode_update().

	 */

	if (ovl_same_sb(inode->i_sb) || xinobits) {

	if (ovl_same_dev(inode->i_sb)) {

		inode->i_ino = ino;

		if (xinobits && fsid && !(ino >> (64 - xinobits)))

			inode->i_ino |= (unsigned long)fsid << (64 - xinobits);

fs/overlayfs/overlayfs.h

+13 −4
Original line number Diff line number Diff line
@@ -224,7 +224,6 @@ int ovl_want_write(struct dentry *dentry); 
void ovl_drop_write(struct dentry *dentry);

struct dentry *ovl_workdir(struct dentry *dentry);

const struct cred *ovl_override_creds(struct super_block *sb);

struct super_block *ovl_same_sb(struct super_block *sb);

int ovl_can_decode_fh(struct super_block *sb);

struct dentry *ovl_indexdir(struct super_block *sb);

bool ovl_index_all(struct super_block *sb);
@@ -302,11 +301,21 @@ static inline bool ovl_is_impuredir(struct dentry *dentry) 
	return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);

}



static inline unsigned int ovl_xino_bits(struct super_block *sb)

/* All layers on same fs? */

static inline bool ovl_same_fs(struct super_block *sb)

{

	struct ovl_fs *ofs = sb->s_fs_info;

	return OVL_FS(sb)->xino_mode == 0;

}



	return ofs->xino_bits;

/* All overlay inodes have same st_dev? */

static inline bool ovl_same_dev(struct super_block *sb)

{

	return OVL_FS(sb)->xino_mode >= 0;

}



static inline unsigned int ovl_xino_bits(struct super_block *sb)

{

	return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;

}



static inline int ovl_inode_lock(struct inode *inode)

fs/overlayfs/ovl_entry.h

+7 −2
Original line number Diff line number Diff line
@@ -71,10 +71,15 @@ struct ovl_fs { 
	struct inode *workbasedir_trap;

	struct inode *workdir_trap;

	struct inode *indexdir_trap;

	/* Inode numbers in all layers do not use the high xino_bits */

	unsigned int xino_bits;

	/* -1: disabled, 0: same fs, 1..32: number of unused ino bits */

	int xino_mode;

};



static inline struct ovl_fs *OVL_FS(struct super_block *sb)

{

	return (struct ovl_fs *)sb->s_fs_info;

}



/* private information held for every overlayfs dentry */

struct ovl_entry {

	union {

fs/overlayfs/readdir.c

+2 −2
Original line number Diff line number Diff line
@@ -469,7 +469,7 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) 
	int xinobits = ovl_xino_bits(dir->d_sb);

	int err = 0;



	if (!ovl_same_sb(dir->d_sb) && !xinobits)

	if (!ovl_same_dev(dir->d_sb))

		goto out;



	if (p->name[0] == '.') {
@@ -744,7 +744,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) 
		 * entries.

		 */

		if (ovl_xino_bits(dentry->d_sb) ||

		    (ovl_same_sb(dentry->d_sb) &&

		    (ovl_same_fs(dentry->d_sb) &&

		     (ovl_is_impure_dir(file) ||

		      OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {

			return ovl_iterate_real(file, ctx);

fs/overlayfs/super.c

+11 −10
Original line number Diff line number Diff line
@@ -358,7 +358,7 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) 
	if (ofs->config.nfs_export != ovl_nfs_export_def)

		seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ?

						"on" : "off");

	if (ofs->config.xino != ovl_xino_def())

	if (ofs->config.xino != ovl_xino_def() && !ovl_same_fs(sb))

		seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]);

	if (ofs->config.metacopy != ovl_metacopy_def)

		seq_printf(m, ",metacopy=%s",
@@ -811,7 +811,7 @@ static int ovl_lower_dir(const char *name, struct path *path, 


	/* Check if lower fs has 32bit inode numbers */

	if (fh_type != FILEID_INO32_GEN)

		ofs->xino_bits = 0;

		ofs->xino_mode = -1;



	return 0;
@@ -1142,7 +1142,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, 


	/* Check if upper fs has 32bit inode numbers */

	if (fh_type != FILEID_INO32_GEN)

		ofs->xino_bits = 0;

		ofs->xino_mode = -1;



	/* NFS export of r/w mount depends on index */

	if (ofs->config.nfs_export && !ofs->config.index) {
@@ -1395,21 +1395,22 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs, 
	 * inode number.

	 */

	if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_mnt)) {

		ofs->xino_bits = 0;

		ofs->config.xino = OVL_XINO_OFF;

	} else if (ofs->config.xino == OVL_XINO_ON && !ofs->xino_bits) {

		if (ofs->config.xino == OVL_XINO_ON)

			pr_info("\"xino=on\" is useless with all layers on same fs, ignore.\n");

		ofs->xino_mode = 0;

	} else if (ofs->config.xino == OVL_XINO_ON && ofs->xino_mode < 0) {

		/*

		 * This is a roundup of number of bits needed for numlowerfs+1

		 * (i.e. ilog2(numlowerfs+1 - 1) + 1). fsid 0 is reserved for

		 * upper fs even with non upper overlay.

		 */

		BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31);

		ofs->xino_bits = ilog2(ofs->numlowerfs) + 1;

		ofs->xino_mode = ilog2(ofs->numlowerfs) + 1;

	}



	if (ofs->xino_bits) {

	if (ofs->xino_mode > 0) {

		pr_info("\"xino\" feature enabled using %d upper inode bits.\n",

			ofs->xino_bits);

			ofs->xino_mode);

	}



	err = 0;
@@ -1610,7 +1611,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	sb->s_maxbytes = MAX_LFS_FILESIZE;

	/* Assume underlaying fs uses 32bit inodes unless proven otherwise */

	if (ofs->config.xino != OVL_XINO_OFF)

		ofs->xino_bits = BITS_PER_LONG - 32;

		ofs->xino_mode = BITS_PER_LONG - 32;



	/* alloc/destroy_inode needed for setting up traps in inode cache */

	sb->s_op = &ovl_super_operations;

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