On Wed 08-01-14 23:10:15, Miklos Szeredi wrote:
> From: Miklos Szeredi <mszer...@suse.cz>
>
> Implement RENAME_EXCHANGE flag in renameat2 syscall.
Yes, this is much better than last time. Thanks for the work. You can add
Reviewed-by: Jan Kara <j...@suse.cz>
One nitpick below...
> Signed-off-by: Miklos Szeredi <mszer...@suse.cz>
> ---
> fs/ext4/namei.c | 121
> ++++++++++++++++++++++++++++++++++++++++----------------
> 1 file changed, 87 insertions(+), 34 deletions(-)
>
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 7147d08a43a2..e4513ba7ed99 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -3005,6 +3005,8 @@ struct ext4_renament {
> struct inode *dir;
> struct dentry *dentry;
> struct inode *inode;
> + bool is_dir;
> + int dir_nlink_delta;
>
> /* entry for "dentry" */
> struct buffer_head *bh;
> @@ -3136,6 +3138,14 @@ static void ext4_rename_delete(handle_t *handle,
> struct ext4_renament *ent)
> }
> }
>
> +static void ext4_update_dir_count(handle_t *handle, struct ext4_renament
> *ent)
> +{
> + if (ent->dir_nlink_delta == -1)
> + ext4_dec_count(handle, ent->dir);
> + else if (ent->dir_nlink_delta == 1)
> + ext4_inc_count(handle, ent->dir);
> +}
> +
> /*
> * Anybody can rename anything with this: the permission checks are left to
> the
> * higher-level routines.
> @@ -3161,7 +3171,7 @@ static int ext4_rename(struct inode *old_dir, struct
> dentry *old_dentry,
> };
> int retval;
>
> - if (flags & ~RENAME_NOREPLACE)
> + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
> return -EOPNOTSUPP;
>
> dquot_initialize(old.dir);
> @@ -3169,10 +3179,11 @@ static int ext4_rename(struct inode *old_dir, struct
> dentry *old_dentry,
>
> /* Initialize quotas before so that eventual writes go
> * in separate transaction */
> - if (new.inode)
> + if (!(flags & RENAME_EXCHANGE) && new.inode)
> dquot_initialize(new.inode);
>
> - old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
> + old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
> + &old.de, &old.inlined);
> /*
> * Check for inode number is _not_ due to possible IO errors.
> * We might rmdir the source, keep it as pwd of some process
> @@ -3185,18 +3196,22 @@ static int ext4_rename(struct inode *old_dir, struct
> dentry *old_dentry,
>
> new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
> &new.de, &new.inlined);
> - if (new.bh) {
> - if (!new.inode) {
> - brelse(new.bh);
> - new.bh = NULL;
> + if (!(flags & RENAME_EXCHANGE)) {
> + if (new.bh) {
> + if (!new.inode) {
> + brelse(new.bh);
> + new.bh = NULL;
> + }
> }
> + if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
> + ext4_alloc_da_blocks(old.inode);
> + } else if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) {
> + goto end_rename;
> }
I think this deserves a comment that RENAME_EXCHANGE expects both source
and target to exist... I'm always pondering about this condition before I
realize that.
Honza
--
Jan Kara <j...@suse.cz>
SUSE Labs, CR
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