From 12ff95ff579d0203790aff69632c7ab12ce56140 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Wed, 9 Nov 2011 12:29:51 -0800 Subject: [PATCH] Linux 3.1 compat, kern_path_parent() Prior to Linux 3.1 the kern_path_parent symbol was exported for use by kernel modules. As of Linux 3.1 it is now longer easily available. To handle this case the spl will now dynamically look up address of the missing symbol at module load time. Signed-off-by: Brian Behlendorf Issue #52 --- config/spl-build.m4 | 47 +++++++++++++++++++++++++-- configure | 64 ++++++++++++++++++++++++++++++++++--- include/linux/file_compat.h | 14 +++++--- include/sys/vnode.h | 5 +-- module/spl/spl-generic.c | 9 ++++-- module/spl/spl-vnode.c | 27 ++++++++++++++-- spl_config.h.in | 5 ++- 7 files changed, 152 insertions(+), 19 deletions(-) diff --git a/config/spl-build.m4 b/config/spl-build.m4 index c046db8..f5696b9 100644 --- a/config/spl-build.m4 +++ b/config/spl-build.m4 @@ -80,7 +80,8 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [ SPL_AC_KERNEL_2ARGS_INVALIDATE_INODES SPL_AC_SHRINK_DCACHE_MEMORY SPL_AC_SHRINK_ICACHE_MEMORY - SPL_AC_KERN_PATH_PARENT + SPL_AC_KERN_PATH_PARENT_HEADER + SPL_AC_KERN_PATH_PARENT_SYMBOL SPL_AC_2ARGS_ZLIB_DEFLATE_WORKSPACESIZE SPL_AC_SHRINK_CONTROL_STRUCT ]) @@ -587,6 +588,30 @@ AC_DEFUN([SPL_CHECK_SYMBOL_EXPORT], fi ]) +dnl # +dnl # SPL_CHECK_SYMBOL_HEADER +dnl # check if a symbol prototype is defined in listed headers. +dnl # +AC_DEFUN([SPL_CHECK_SYMBOL_HEADER], [ + AC_MSG_CHECKING([whether symbol $1 exists in header]) + header=0 + for file in $3; do + grep -q "$2" "$LINUX/$file" 2>/dev/null + rc=$? + if test $rc -eq 0; then + header=1 + break; + fi + done + if test $header -eq 0; then + AC_MSG_RESULT([no]) + $5 + else + AC_MSG_RESULT([yes]) + $4 + fi +]) + dnl # dnl # SPL_CHECK_HEADER dnl # check whether header exists and define HAVE_$2_HEADER @@ -1809,11 +1834,27 @@ dnl # and the flags argument has been removed. The only behavior now dnl # offered is that of LOOKUP_PARENT. The spl already always passed dnl # this flag so dropping the flag does not impact us. dnl # -AC_DEFUN([SPL_AC_KERN_PATH_PARENT], [ +AC_DEFUN([SPL_AC_KERN_PATH_PARENT_HEADER], [ + SPL_CHECK_SYMBOL_HEADER( + [kern_path_parent], + [int kern_path_parent(const char \*, struct nameidata \*)], + [include/linux/namei.h], + [AC_DEFINE(HAVE_KERN_PATH_PARENT_HEADER, 1, + [kern_path_parent() is available])], + []) +]) + +dnl # +dnl # 3.1 API compat, +dnl # The kern_path_parent() symbol is no longer exported by the kernel. +dnl # However, it remains the prefered interface and since we still have +dnl # access to the prototype we dynamically lookup the required address. +dnl # +AC_DEFUN([SPL_AC_KERN_PATH_PARENT_SYMBOL], [ SPL_CHECK_SYMBOL_EXPORT( [kern_path_parent], [fs/namei.c], - [AC_DEFINE(HAVE_KERN_PATH_PARENT, 1, + [AC_DEFINE(HAVE_KERN_PATH_PARENT_SYMBOL, 1, [kern_path_parent() is available])], []) ]) diff --git a/configure b/configure index 1369ca0..beeb6d5 100755 --- a/configure +++ b/configure @@ -15684,6 +15684,34 @@ _ACEOF + + { $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent exists in header" >&5 +$as_echo_n "checking whether symbol kern_path_parent exists in header... " >&6; } + header=0 + for file in include/linux/namei.h; do + grep -q "int kern_path_parent(const char \*, struct nameidata \*)" "$LINUX/$file" 2>/dev/null + rc=$? + if test $rc -eq 0; then + header=1 + break; + fi + done + if test $header -eq 0; then + { $as_echo "$as_me:$LINENO: result: no" >&5 +$as_echo "no" >&6; } + + else + { $as_echo "$as_me:$LINENO: result: yes" >&5 +$as_echo "yes" >&6; } + +cat >>confdefs.h <<\_ACEOF +#define HAVE_KERN_PATH_PARENT_HEADER 1 +_ACEOF + + fi + + + { $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent is exported" >&5 $as_echo_n "checking whether symbol kern_path_parent is exported... " >&6; } grep -q -E '[[:space:]]kern_path_parent[[:space:]]' \ @@ -15709,7 +15737,7 @@ $as_echo "no" >&6; } $as_echo "yes" >&6; } cat >>confdefs.h <<\_ACEOF -#define HAVE_KERN_PATH_PARENT 1 +#define HAVE_KERN_PATH_PARENT_SYMBOL 1 _ACEOF fi @@ -15718,7 +15746,7 @@ _ACEOF $as_echo "yes" >&6; } cat >>confdefs.h <<\_ACEOF -#define HAVE_KERN_PATH_PARENT 1 +#define HAVE_KERN_PATH_PARENT_SYMBOL 1 _ACEOF fi @@ -19885,6 +19913,34 @@ _ACEOF + + { $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent exists in header" >&5 +$as_echo_n "checking whether symbol kern_path_parent exists in header... " >&6; } + header=0 + for file in include/linux/namei.h; do + grep -q "int kern_path_parent(const char \*, struct nameidata \*)" "$LINUX/$file" 2>/dev/null + rc=$? + if test $rc -eq 0; then + header=1 + break; + fi + done + if test $header -eq 0; then + { $as_echo "$as_me:$LINENO: result: no" >&5 +$as_echo "no" >&6; } + + else + { $as_echo "$as_me:$LINENO: result: yes" >&5 +$as_echo "yes" >&6; } + +cat >>confdefs.h <<\_ACEOF +#define HAVE_KERN_PATH_PARENT_HEADER 1 +_ACEOF + + fi + + + { $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent is exported" >&5 $as_echo_n "checking whether symbol kern_path_parent is exported... " >&6; } grep -q -E '[[:space:]]kern_path_parent[[:space:]]' \ @@ -19910,7 +19966,7 @@ $as_echo "no" >&6; } $as_echo "yes" >&6; } cat >>confdefs.h <<\_ACEOF -#define HAVE_KERN_PATH_PARENT 1 +#define HAVE_KERN_PATH_PARENT_SYMBOL 1 _ACEOF fi @@ -19919,7 +19975,7 @@ _ACEOF $as_echo "yes" >&6; } cat >>confdefs.h <<\_ACEOF -#define HAVE_KERN_PATH_PARENT 1 +#define HAVE_KERN_PATH_PARENT_SYMBOL 1 _ACEOF fi diff --git a/include/linux/file_compat.h b/include/linux/file_compat.h index 97bd763..d5fb2bc 100644 --- a/include/linux/file_compat.h +++ b/include/linux/file_compat.h @@ -67,11 +67,17 @@ spl_filp_open(const char *name, int flags, int mode, int *err) #define spl_inode_unlock(ip) (up(&(ip)->i_sem)) #endif /* HAVE_INODE_I_MUTEX */ -#ifdef HAVE_KERN_PATH_PARENT -#define spl_kern_path_parent(path, nd) kern_path_parent(path, nd) +#ifdef HAVE_KERN_PATH_PARENT_HEADER +# ifndef HAVE_KERN_PATH_PARENT_SYMBOL +typedef int (*kern_path_parent_t)(const char *, struct nameidata *); +extern kern_path_parent_t kern_path_parent_fn; +# define spl_kern_path_parent(path, nd) kern_path_parent_fn(path, nd) +# else +# define spl_kern_path_parent(path, nd) kern_path_parent(path, nd) +# endif /* HAVE_KERN_PATH_PARENT_SYMBOL */ #else -#define spl_kern_path_parent(path, nd) path_lookup(path, LOOKUP_PARENT, nd) -#endif /* HAVE_KERN_PATH_PARENT */ +# define spl_kern_path_parent(path, nd) path_lookup(path, LOOKUP_PARENT, nd) +#endif /* HAVE_KERN_PATH_PARENT_HEADER */ #endif /* SPL_FILE_COMPAT_H */ diff --git a/include/sys/vnode.h b/include/sys/vnode.h index 36605ca..03462bd 100644 --- a/include/sys/vnode.h +++ b/include/sys/vnode.h @@ -189,8 +189,9 @@ extern file_t *vn_getf(int fd); extern void vn_releasef(int fd); extern int vn_set_pwd(const char *filename); -int vn_init(void); -void vn_fini(void); +int spl_vn_init_kallsyms_lookup(void); +int spl_vn_init(void); +void spl_vn_fini(void); #define VOP_CLOSE vn_close #define VOP_SEEK vn_seek diff --git a/module/spl/spl-generic.c b/module/spl/spl-generic.c index 1dedf76..3f042cc 100644 --- a/module/spl/spl-generic.c +++ b/module/spl/spl-generic.c @@ -561,7 +561,7 @@ __init spl_init(void) if ((rc = spl_taskq_init())) SGOTO(out4, rc); - if ((rc = vn_init())) + if ((rc = spl_vn_init())) SGOTO(out5, rc); if ((rc = proc_init())) @@ -594,6 +594,9 @@ __init spl_init(void) if ((rc = spl_kmem_init_kallsyms_lookup())) SGOTO(out10, rc); + if ((rc = spl_vn_init_kallsyms_lookup())) + SGOTO(out10, rc); + printk(KERN_NOTICE "SPL: Loaded module v%s%s, using hostid 0x%08x\n", SPL_META_VERSION, SPL_DEBUG_STR, (unsigned int) spl_hostid); SRETURN(rc); @@ -606,7 +609,7 @@ out8: out7: proc_fini(); out6: - vn_fini(); + spl_vn_fini(); out5: spl_taskq_fini(); out4: @@ -634,7 +637,7 @@ spl_fini(void) tsd_fini(); kstat_fini(); proc_fini(); - vn_fini(); + spl_vn_fini(); spl_taskq_fini(); spl_rw_fini(); spl_mutex_fini(); diff --git a/module/spl/spl-vnode.c b/module/spl/spl-vnode.c index 354e879..cd0fa2c 100644 --- a/module/spl/spl-vnode.c +++ b/module/spl/spl-vnode.c @@ -42,6 +42,13 @@ static spl_kmem_cache_t *vn_file_cache; static DEFINE_SPINLOCK(vn_file_lock); static LIST_HEAD(vn_file_list); +#ifdef HAVE_KERN_PATH_PARENT_HEADER +#ifndef HAVE_KERN_PATH_PARENT_SYMBOL +kern_path_parent_t kern_path_parent_fn = SYMBOL_POISON; +EXPORT_SYMBOL(kern_path_parent_fn); +#endif /* HAVE_KERN_PATH_PARENT_SYMBOL */ +#endif /* HAVE_KERN_PATH_PARENT_HEADER */ + vtype_t vn_mode_to_vtype(mode_t mode) { @@ -789,8 +796,24 @@ vn_file_cache_destructor(void *buf, void *cdrarg) mutex_destroy(&fp->f_lock); } /* vn_file_cache_destructor() */ +int spl_vn_init_kallsyms_lookup(void) +{ +#ifdef HAVE_KERN_PATH_PARENT_HEADER +#ifndef HAVE_KERN_PATH_PARENT_SYMBOL + kern_path_parent_fn = (kern_path_parent_t) + spl_kallsyms_lookup_name("kern_path_parent"); + if (!kern_path_parent_fn) { + printk(KERN_ERR "Error: Unknown symbol kern_path_parent\n"); + return -EFAULT; + } +#endif /* HAVE_KERN_PATH_PARENT_SYMBOL */ +#endif /* HAVE_KERN_PATH_PARENT_HEADER */ + + return (0); +} + int -vn_init(void) +spl_vn_init(void) { SENTRY; vn_cache = kmem_cache_create("spl_vn_cache", @@ -808,7 +831,7 @@ vn_init(void) } /* vn_init() */ void -vn_fini(void) +spl_vn_fini(void) { file_t *fp, *next_fp; int leaked = 0; diff --git a/spl_config.h.in b/spl_config.h.in index 97f0e06..6122059 100644 --- a/spl_config.h.in +++ b/spl_config.h.in @@ -115,7 +115,10 @@ #undef HAVE_KALLSYMS_LOOKUP_NAME /* kern_path_parent() is available */ -#undef HAVE_KERN_PATH_PARENT +#undef HAVE_KERN_PATH_PARENT_HEADER + +/* kern_path_parent() is available */ +#undef HAVE_KERN_PATH_PARENT_SYMBOL /* kmalloc_node() is available */ #undef HAVE_KMALLOC_NODE -- 2.39.2