From dae2f8ed7992e88c8d62c54e8295ffc8475b4a80 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 30 Apr 2020 07:41:37 -0700 Subject: fs: Lift XFS_IDONTCACHE to the VFS layer DAX effective mode (S_DAX) changes requires inode eviction. XFS has an advisory flag (XFS_IDONTCACHE) to prevent caching of the inode if no other additional references are taken. We lift this flag to the VFS layer and change the behavior slightly by allowing the flag to remain even if multiple references are taken. This will expedite the eviction of inodes to change S_DAX. Cc: Al Viro Reviewed-by: Dave Chinner Reviewed-by: Jan Kara Signed-off-by: Ira Weiny Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- include/linux/fs.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index a87cc5845a02..44bd45af760f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2156,6 +2156,8 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, * * I_CREATING New object's inode in the middle of setting up. * + * I_DONTCACHE Evict inode as soon as it is not used anymore. + * * Q: What is the difference between I_WILL_FREE and I_FREEING? */ #define I_DIRTY_SYNC (1 << 0) @@ -2178,6 +2180,7 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, #define I_WB_SWITCH (1 << 13) #define I_OVL_INUSE (1 << 14) #define I_CREATING (1 << 15) +#define I_DONTCACHE (1 << 16) #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC) #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES) @@ -3049,7 +3052,8 @@ extern int inode_needs_sync(struct inode *inode); extern int generic_delete_inode(struct inode *inode); static inline int generic_drop_inode(struct inode *inode) { - return !inode->i_nlink || inode_unhashed(inode); + return !inode->i_nlink || inode_unhashed(inode) || + (inode->i_state & I_DONTCACHE); } extern struct inode *ilookup5_nowait(struct super_block *sb, -- cgit v1.2.3-59-g8ed1b From 2c567af418e3f9380c2051aada58b4e5a4b5c2ad Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 30 Apr 2020 07:41:37 -0700 Subject: fs: Introduce DCACHE_DONTCACHE DCACHE_DONTCACHE indicates a dentry should not be cached on final dput(). Also add a helper function to mark DCACHE_DONTCACHE on all dentries pointing to a specific inode when that inode is being set I_DONTCACHE. This facilitates dropping dentry references to inodes sooner which require eviction to swap S_DAX mode. Cc: Al Viro Signed-off-by: Ira Weiny Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/dcache.c | 19 +++++++++++++++++++ fs/xfs/xfs_icache.c | 2 +- include/linux/dcache.h | 2 ++ include/linux/fs.h | 1 + 4 files changed, 23 insertions(+), 1 deletion(-) (limited to 'include/linux/fs.h') diff --git a/fs/dcache.c b/fs/dcache.c index b280e07e162b..0d07fb335b78 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -647,6 +647,10 @@ static inline bool retain_dentry(struct dentry *dentry) if (dentry->d_op->d_delete(dentry)) return false; } + + if (unlikely(dentry->d_flags & DCACHE_DONTCACHE)) + return false; + /* retain; LRU fodder */ dentry->d_lockref.count--; if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) @@ -656,6 +660,21 @@ static inline bool retain_dentry(struct dentry *dentry) return true; } +void d_mark_dontcache(struct inode *inode) +{ + struct dentry *de; + + spin_lock(&inode->i_lock); + hlist_for_each_entry(de, &inode->i_dentry, d_u.d_alias) { + spin_lock(&de->d_lock); + de->d_flags |= DCACHE_DONTCACHE; + spin_unlock(&de->d_lock); + } + inode->i_state |= I_DONTCACHE; + spin_unlock(&inode->i_lock); +} +EXPORT_SYMBOL(d_mark_dontcache); + /* * Finish off a dentry we've decided to kill. * dentry->d_lock must be held, returns with it unlocked. diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index fa8554b3308d..d7deab608e2c 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -561,7 +561,7 @@ xfs_iget_cache_miss( */ iflags = XFS_INEW; if (flags & XFS_IGET_DONTCACHE) - VFS_I(ip)->i_state |= I_DONTCACHE; + d_mark_dontcache(VFS_I(ip)); ip->i_udquot = NULL; ip->i_gdquot = NULL; ip->i_pdquot = NULL; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index c1488cc84fd9..a81f0c3cf352 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -177,6 +177,8 @@ struct dentry_operations { #define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */ +#define DCACHE_DONTCACHE 0x00000080 /* Purge from memory on final dput() */ + #define DCACHE_CANT_MOUNT 0x00000100 #define DCACHE_GENOCIDE 0x00000200 #define DCACHE_SHRINK_LIST 0x00000400 diff --git a/include/linux/fs.h b/include/linux/fs.h index 44bd45af760f..7c3e8c0306e0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3055,6 +3055,7 @@ static inline int generic_drop_inode(struct inode *inode) return !inode->i_nlink || inode_unhashed(inode) || (inode->i_state & I_DONTCACHE); } +extern void d_mark_dontcache(struct inode *inode); extern struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), -- cgit v1.2.3-59-g8ed1b