From a118084432d642eeccb961c7c8cc61525a941fcb Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 20 May 2016 22:13:45 +0200 Subject: vfs: add d_real_inode() helper Needed by the following fix. Signed-off-by: Miklos Szeredi Cc: --- include/linux/dcache.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/dcache.h') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 7e9422cb5989..ad5d582f9b14 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -576,5 +576,17 @@ static inline struct inode *vfs_select_inode(struct dentry *dentry, return inode; } +/** + * d_real_inode - Return the real inode + * @dentry: The dentry to query + * + * If dentry is on an union/overlay, then return the underlying, real inode. + * Otherwise return d_inode(). + */ +static inline struct inode *d_real_inode(struct dentry *dentry) +{ + return d_backing_inode(d_real(dentry)); +} + #endif /* __LINUX_DCACHE_H */ -- cgit v1.2.3 From f4bcbe792b8f434e32487cff9d9e30ab45a3ce02 Mon Sep 17 00:00:00 2001 From: George Spelvin Date: Fri, 20 May 2016 07:26:00 -0400 Subject: Pull out string hash to ... so they can be used without the rest of The hashlen_* macros will make sense next patch. Signed-off-by: George Spelvin --- include/linux/dcache.h | 27 +-------------------------- 1 file changed, 1 insertion(+), 26 deletions(-) (limited to 'include/linux/dcache.h') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 7e9422cb5989..0f9a977c334f 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -10,6 +10,7 @@ #include #include #include +#include struct path; struct vfsmount; @@ -52,9 +53,6 @@ struct qstr { }; #define QSTR_INIT(n,l) { { { .len = l } }, .name = n } -#define hashlen_hash(hashlen) ((u32) (hashlen)) -#define hashlen_len(hashlen) ((u32)((hashlen) >> 32)) -#define hashlen_create(hash,len) (((u64)(len)<<32)|(u32)(hash)) struct dentry_stat_t { long nr_dentry; @@ -65,29 +63,6 @@ struct dentry_stat_t { }; extern struct dentry_stat_t dentry_stat; -/* Name hashing routines. Initial hash value */ -/* Hash courtesy of the R5 hash in reiserfs modulo sign bits */ -#define init_name_hash() 0 - -/* partial hash update function. Assume roughly 4 bits per character */ -static inline unsigned long -partial_name_hash(unsigned long c, unsigned long prevhash) -{ - return (prevhash + (c << 4) + (c >> 4)) * 11; -} - -/* - * Finally: cut down the number of bits to a int value (and try to avoid - * losing bits) - */ -static inline unsigned long end_name_hash(unsigned long hash) -{ - return (unsigned int) hash; -} - -/* Compute the hash for a name string. */ -extern unsigned int full_name_hash(const unsigned char *, unsigned int); - /* * Try to keep struct dentry aligned on 64 byte cachelines (this will * give reasonable cacheline footprint with larger lines without the -- cgit v1.2.3 From ba65dc5ef16f82fba77869cecf7a7d515f61446b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 10 Jun 2016 11:32:47 -0400 Subject: much milder d_walk() race d_walk() relies upon the tree not getting rearranged under it without rename_lock being touched. And we do grab rename_lock around the places that change the tree topology. Unfortunately, branch reordering is just as bad from d_walk() POV and we have two places that do it without touching rename_lock - one in handling of cursors (for ramfs-style directories) and another in autofs. autofs one is a separate story; this commit deals with the cursors. * mark cursor dentries explicitly at allocation time * make __dentry_kill() leave ->d_child.next pointing to the next non-cursor sibling, making sure that it won't be moved around unnoticed before the parent is relocked on ascend-to-parent path in d_walk(). * make d_walk() skip cursors explicitly; strictly speaking it's not necessary (all callbacks we pass to d_walk() are no-ops on cursors), but it makes analysis easier. Signed-off-by: Al Viro --- include/linux/dcache.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/dcache.h') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 484c8792da82..bcd0c64e3ed8 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -212,6 +212,7 @@ struct dentry_operations { #define DCACHE_OP_REAL 0x08000000 #define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */ +#define DCACHE_DENTRY_CURSOR 0x20000000 extern seqlock_t rename_lock; -- cgit v1.2.3