From 269e2ccf45ddc662d8373eb887ae6cef96e2ef37 Mon Sep 17 00:00:00 2001 From: Mohammed Rafi KC Date: Wed, 3 May 2017 17:19:57 +0530 Subject: gfapi: fix handling of dot and double dot in path This patch is to handle "." and ".." in file path. Which means this special dentry names will be resolved before sending fops on the path. Change-Id: I5e92f6d1ad1412bf432eb2488e53fb7731edb013 BUG: 1447266 Signed-off-by: Mohammed Rafi KC Reviewed-on: https://review.gluster.org/17177 Smoke: Gluster Build System Reviewed-by: Niels de Vos CentOS-regression: Gluster Build System NetBSD-regression: NetBSD Build System Reviewed-by: Jeff Darcy --- api/src/glfs-resolve.c | 41 ++++++++---------- libglusterfs/src/inode.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++ libglusterfs/src/inode.h | 17 ++++++++ 3 files changed, 144 insertions(+), 24 deletions(-) diff --git a/api/src/glfs-resolve.c b/api/src/glfs-resolve.c index d495cd21413..a2be87f1c1e 100644 --- a/api/src/glfs-resolve.c +++ b/api/src/glfs-resolve.c @@ -25,12 +25,10 @@ #include "syncop.h" #include "call-stub.h" #include "gfapi-messages.h" - +#include "inode.h" #include "glfs-internal.h" #define graphid_str(subvol) (uuid_utoa((unsigned char *)subvol->graph->graph_uuid)) - - int glfs_first_lookup_safe (xlator_t *subvol) { @@ -251,33 +249,26 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, loc.parent = inode_ref (parent); gf_uuid_copy (loc.pargfid, parent->gfid); - /* /.. and /. should point back to / - we lookup using inode and gfid of root - Fill loc.name so that we make use md-cache. - md-cache is not valid for nameless lookups. - */ + /* At this point we should never have '.' or ".." in path */ if (__is_root_gfid (parent->gfid) && - (strcmp (component, "..") == 0)) { - loc.inode = inode_ref (parent); - loc.name = "."; - } else { - if (strcmp (component, ".") == 0) - loc.inode = inode_ref (parent); - else if (strcmp (component, "..") == 0) - loc.inode = inode_parent (parent, 0, 0); - else - loc.inode = inode_grep (parent->table, parent, - component); + (strcmp (component, "/") == 0)) { + if (!force_lookup) { + inode = inode_ref (parent); + } else { + ret = glfs_resolve_base (fs, subvol, parent, &ciatt); + if (!ret) + inode = inode_ref (parent); + } + goto found; } - + loc.inode = inode_grep (parent->table, parent, component); if (loc.inode) { gf_uuid_copy (loc.gfid, loc.inode->gfid); reval = 1; if (!(force_lookup || inode_needs_lookup (loc.inode, THIS))) { inode = inode_ref (loc.inode); - ciatt.ia_type = inode->ia_type; goto found; } } else { @@ -357,8 +348,10 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, } else if (inode == loc.inode) inode_ctx_set (inode, THIS, &ctx_value); found: - if (inode) + if (inode) { + ciatt.ia_type = inode->ia_type; inode_lookup (inode); + } if (iatt) *iatt = ciatt; out: @@ -384,6 +377,7 @@ priv_glfs_resolve_at (struct glfs *fs, xlator_t *subvol, inode_t *at, char *next_component = NULL; int ret = -1; struct iatt ciatt = {0, }; + char dentry_name[PATH_MAX] = {0, }; DECLARE_OLD_THIS; __GLFS_ENTRY_VALIDATE_FS(fs, invalid_fs); @@ -414,9 +408,8 @@ priv_glfs_resolve_at (struct glfs *fs, xlator_t *subvol, inode_t *at, if (parent) inode_unref (parent); - parent = inode; - + glusterfs_normalize_dentry (&parent, &component, dentry_name); inode = glfs_resolve_component (fs, subvol, parent, component, &ciatt, /* force hard lookup on the last diff --git a/libglusterfs/src/inode.c b/libglusterfs/src/inode.c index 3a6464ac5e1..6f3bc535a14 100644 --- a/libglusterfs/src/inode.c +++ b/libglusterfs/src/inode.c @@ -2569,3 +2569,113 @@ inode_ctx_size (inode_t *inode) out: return size; } + +static void +inode_parent_null_check(inode_t **parent, inode_t *inode, char **component) +{ + GF_VALIDATE_OR_GOTO ("inode", inode, out); + GF_VALIDATE_OR_GOTO ("inode", (*component), out); + + if (!(*parent) && __is_root_gfid (inode->gfid)) { + *parent = inode_ref (inode); + *component = "/"; + } +out: + return; +} + +/* + * This function changes component name and parent inode + * if the component name is either "." or ".." + * + * @Paramas: + * Parent : Parent inode of current dentry + * component : component name that we need to test + * dentry_name : Address for memory if need to change component. + * The caller has to preallocate this memory with + * PATH_MAX as the size. + * + * We return the updated parent inode and component in the + * respective structures. + * + * Basic Idea of the function: + * + * Example 1 : + * Path /out_dir/dir/in_dir/. + * In put values : + * parent = in_dir + * component : "." + * + * Out put values: + * parent : dir + * component : "in_dir" + * + * Example 2 : + * Path /out_dir/dir/in_dir/.. + * In put values : + * parent = in_dir + * component : ".." + * + * Out put values: + * parent : output_dir + * component : "dir" + */ +void +glusterfs_normalize_dentry (inode_t **parent, char **component, + char *dentry_name) +{ + inode_t *temp_inode = NULL; + dentry_t *dentry = NULL; + + GF_VALIDATE_OR_GOTO ("inode", (*parent), out); + GF_VALIDATE_OR_GOTO ("inode", (*component), out); + GF_VALIDATE_OR_GOTO ("inode", (dentry_name), out); + + /* After this point, there should not be "." or ".." + * in the path. Dot and double dots are replaced with + * appropriate base name and parent inode. + */ + + /* During the resolving, if it goes beyond the mount point + * we do lookup on the mount itself like "/.. " will be + * converted as "/" + */ + if (strcmp (*component, ".") == 0) { + temp_inode = *parent; + *parent = inode_parent (*parent, 0, 0); + inode_parent_null_check (parent, temp_inode, component); + pthread_mutex_lock (&temp_inode->table->lock); + { + dentry = __dentry_search_arbit (temp_inode); + if (dentry) { + snprintf (dentry_name, PATH_MAX, "%s", + dentry->name); + *component = dentry_name; + } + } + pthread_mutex_unlock (&temp_inode->table->lock); + inode_unref (temp_inode); + } else if (strcmp (*component, "..") == 0) { + temp_inode = *parent; + *parent = inode_parent (*parent, 0, 0); + inode_parent_null_check (parent, temp_inode, component); + inode_unref (temp_inode); + + temp_inode = *parent; + *parent = inode_parent (*parent, 0, 0); + inode_parent_null_check (parent, temp_inode, component); + pthread_mutex_lock (&temp_inode->table->lock); + { + dentry = __dentry_search_arbit (temp_inode); + if (dentry) { + snprintf (dentry_name, PATH_MAX, "%s", + dentry->name); + *component = dentry_name; + } + } + pthread_mutex_unlock (&temp_inode->table->lock); + inode_unref (temp_inode); + } +out: + return; +} diff --git a/libglusterfs/src/inode.h b/libglusterfs/src/inode.h index cdc2095a0e8..253196378a8 100644 --- a/libglusterfs/src/inode.h +++ b/libglusterfs/src/inode.h @@ -286,4 +286,21 @@ inode_has_dentry (inode_t *inode); size_t inode_ctx_size (inode_t *inode); +/* + * This function is used to change the dentry from a path + * if it contains any "." or ".." . + * + * It replaces "." and ".." to proper bname after resolving + * and will change the component accordingly. + * + * This fucntion also replaces the parent inode based on the + * bname. + * + * We should give a allocated memory as a third argument to store + * the component in case if we are modifying it. + */ + +void +glusterfs_normalize_dentry (inode_t **parent, char **component, + char *dentry_name); #endif /* _INODE_H */ -- cgit