From 2d902671ce1cd98cdc88d78c481889a1b2996101 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 30 Jun 2016 08:53:27 +0200 Subject: vfs: merge .d_select_inode() into .d_real() The two methods essentially do the same: find the real dentry/inode belonging to an overlay dentry. The difference is in the usage: vfs_open() uses ->d_select_inode() and expects the function to perform copy-up if necessary based on the open flags argument. file_dentry() uses ->d_real() passing in the overlay dentry as well as the underlying inode. vfs_rename() uses ->d_select_inode() but passes zero flags. ->d_real() with a zero inode would have worked just as well here. This patch merges the functionality of ->d_select_inode() into ->d_real() by adding an 'open_flags' argument to the latter. [Al Viro] Make the signature of d_real() match that of ->d_real() again. And constify the inode argument, while we are at it. Signed-off-by: Miklos Szeredi --- fs/overlayfs/inode.c | 31 ++++++++++--------------------- fs/overlayfs/overlayfs.h | 2 +- fs/overlayfs/super.c | 20 ++++++++++++++------ 3 files changed, 25 insertions(+), 28 deletions(-) (limited to 'fs/overlayfs') diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 1dbeab6cf96e..e08cd94d7b26 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -325,36 +325,25 @@ static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type, return true; } -struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags) +int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags) { - int err; + int err = 0; struct path realpath; enum ovl_path_type type; - if (d_is_dir(dentry)) - return d_backing_inode(dentry); - type = ovl_path_real(dentry, &realpath); if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) { err = ovl_want_write(dentry); - if (err) - return ERR_PTR(err); - - if (file_flags & O_TRUNC) - err = ovl_copy_up_truncate(dentry); - else - err = ovl_copy_up(dentry); - ovl_drop_write(dentry); - if (err) - return ERR_PTR(err); - - ovl_path_upper(dentry, &realpath); + if (!err) { + if (file_flags & O_TRUNC) + err = ovl_copy_up_truncate(dentry); + else + err = ovl_copy_up(dentry); + ovl_drop_write(dentry); + } } - if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE) - return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags); - - return d_backing_inode(realpath.dentry); + return err; } static const struct inode_operations ovl_file_inode_operations = { diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 4bd9b5ba8f42..6b9fd25c5ad4 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -179,7 +179,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode, const char *name, void *value, size_t size); ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); int ovl_removexattr(struct dentry *dentry, const char *name); -struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags); +int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, struct ovl_entry *oe); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index ce02f46029da..035c176edf00 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -304,7 +304,9 @@ static void ovl_dentry_release(struct dentry *dentry) } } -static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode) +static struct dentry *ovl_d_real(struct dentry *dentry, + const struct inode *inode, + unsigned int open_flags) { struct dentry *real; @@ -314,6 +316,16 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode) goto bug; } + if (d_is_negative(dentry)) + return dentry; + + if (open_flags) { + int err = ovl_open_maybe_copy_up(dentry, open_flags); + + if (err) + return ERR_PTR(err); + } + real = ovl_dentry_upper(dentry); if (real && (!inode || inode == d_inode(real))) return real; @@ -326,9 +338,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode) return real; /* Handle recursion */ - if (real->d_flags & DCACHE_OP_REAL) - return real->d_op->d_real(real, inode); - + return d_real(real, inode, open_flags); bug: WARN(1, "ovl_d_real(%pd4, %s:%lu\n): real dentry not found\n", dentry, inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0); @@ -378,13 +388,11 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) static const struct dentry_operations ovl_dentry_operations = { .d_release = ovl_dentry_release, - .d_select_inode = ovl_d_select_inode, .d_real = ovl_d_real, }; static const struct dentry_operations ovl_reval_dentry_operations = { .d_release = ovl_dentry_release, - .d_select_inode = ovl_d_select_inode, .d_real = ovl_d_real, .d_revalidate = ovl_dentry_revalidate, .d_weak_revalidate = ovl_dentry_weak_revalidate, -- cgit v1.2.3