From d31a1825450062b85282b4afed1c840fd306d012 Mon Sep 17 00:00:00 2001 From: Carlos Maiolino Date: Wed, 24 Dec 2014 08:51:42 +1100 Subject: [PATCH] xfs: Add support to RENAME_EXCHANGE flag Adds a new function named xfs_cross_rename(), responsible for handling requests from sys_renameat2() using RENAME_EXCHANGE flag. Signed-off-by: Carlos Maiolino Reviewed-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_inode.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++- fs/xfs/xfs_inode.h | 2 +- fs/xfs/xfs_iops.c | 12 +++-- 3 files changed, 142 insertions(+), 6 deletions(-) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 41f804e..9916aef 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -2656,6 +2656,124 @@ xfs_sort_for_rename( } /* + * xfs_cross_rename() + * + * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall + */ +STATIC int +xfs_cross_rename( + struct xfs_trans *tp, + struct xfs_inode *dp1, + struct xfs_name *name1, + struct xfs_inode *ip1, + struct xfs_inode *dp2, + struct xfs_name *name2, + struct xfs_inode *ip2, + struct xfs_bmap_free *free_list, + xfs_fsblock_t *first_block, + int spaceres) +{ + int error = 0; + int ip1_flags = 0; + int ip2_flags = 0; + int dp2_flags = 0; + + /* Swap inode number for dirent in first parent */ + error = xfs_dir_replace(tp, dp1, name1, + ip2->i_ino, + first_block, free_list, spaceres); + if (error) + goto out; + + /* Swap inode number for dirent in second parent */ + error = xfs_dir_replace(tp, dp2, name2, + ip1->i_ino, + first_block, free_list, spaceres); + if (error) + goto out; + + /* + * If we're renaming one or more directories across different parents, + * update the respective ".." entries (and link counts) to match the new + * parents. + */ + if (dp1 != dp2) { + dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG; + + if (S_ISDIR(ip2->i_d.di_mode)) { + error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot, + dp1->i_ino, first_block, + free_list, spaceres); + if (error) + goto out; + + /* transfer ip2 ".." reference to dp1 */ + if (!S_ISDIR(ip1->i_d.di_mode)) { + error = xfs_droplink(tp, dp2); + if (error) + goto out; + error = xfs_bumplink(tp, dp1); + if (error) + goto out; + } + + /* + * Although ip1 isn't changed here, userspace needs + * to be warned about the change, so that applications + * relying on it (like backup ones), will properly + * notify the change + */ + ip1_flags |= XFS_ICHGTIME_CHG; + ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG; + } + + if (S_ISDIR(ip1->i_d.di_mode)) { + error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot, + dp2->i_ino, first_block, + free_list, spaceres); + if (error) + goto out; + + /* transfer ip1 ".." reference to dp2 */ + if (!S_ISDIR(ip2->i_d.di_mode)) { + error = xfs_droplink(tp, dp1); + if (error) + goto out; + error = xfs_bumplink(tp, dp2); + if (error) + goto out; + } + + /* + * Although ip2 isn't changed here, userspace needs + * to be warned about the change, so that applications + * relying on it (like backup ones), will properly + * notify the change + */ + ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG; + ip2_flags |= XFS_ICHGTIME_CHG; + } + } + + if (ip1_flags) { + xfs_trans_ichgtime(tp, ip1, ip1_flags); + xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE); + } + if (ip2_flags) { + xfs_trans_ichgtime(tp, ip2, ip2_flags); + xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE); + } + if (dp2_flags) { + xfs_trans_ichgtime(tp, dp2, dp2_flags); + xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE); + } + xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); + xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE); +out: + return error; +} + +/* * xfs_rename */ int @@ -2665,7 +2783,8 @@ xfs_rename( xfs_inode_t *src_ip, xfs_inode_t *target_dp, struct xfs_name *target_name, - xfs_inode_t *target_ip) + xfs_inode_t *target_ip, + unsigned int flags) { xfs_trans_t *tp = NULL; xfs_mount_t *mp = src_dp->i_mount; @@ -2743,6 +2862,18 @@ xfs_rename( } /* + * Handle RENAME_EXCHANGE flags + */ + if (flags & RENAME_EXCHANGE) { + error = xfs_cross_rename(tp, src_dp, src_name, src_ip, + target_dp, target_name, target_ip, + &free_list, &first_block, spaceres); + if (error) + goto abort_return; + goto finish_rename; + } + + /* * Set up the target. */ if (target_ip == NULL) { @@ -2881,6 +3012,7 @@ xfs_rename( if (new_parent) xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE); +finish_rename: /* * If this is a synchronous mount, make sure that the * rename transaction goes to disk before returning to diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 4ed2ba9..f772296 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -338,7 +338,7 @@ int xfs_link(struct xfs_inode *tdp, struct xfs_inode *sip, int xfs_rename(struct xfs_inode *src_dp, struct xfs_name *src_name, struct xfs_inode *src_ip, struct xfs_inode *target_dp, struct xfs_name *target_name, - struct xfs_inode *target_ip); + struct xfs_inode *target_ip, unsigned int flags); void xfs_ilock(xfs_inode_t *, uint); int xfs_ilock_nowait(xfs_inode_t *, uint); diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index abb838a..ce80eeb 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -384,19 +384,23 @@ xfs_vn_rename( unsigned int flags) { struct inode *new_inode = ndentry->d_inode; + int omode = 0; struct xfs_name oname; struct xfs_name nname; - /* XFS does not support RENAME_EXCHANGE yet */ - if (flags & ~RENAME_NOREPLACE) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) return -EINVAL; - xfs_dentry_to_name(&oname, odentry, 0); + /* if we are exchanging files, we need to set i_mode of both files */ + if (flags & RENAME_EXCHANGE) + omode = ndentry->d_inode->i_mode; + + xfs_dentry_to_name(&oname, odentry, omode); xfs_dentry_to_name(&nname, ndentry, odentry->d_inode->i_mode); return xfs_rename(XFS_I(odir), &oname, XFS_I(odentry->d_inode), XFS_I(ndir), &nname, - new_inode ? XFS_I(new_inode) : NULL); + new_inode ? XFS_I(new_inode) : NULL, flags); } /* -- 2.7.4