From df1a085af1f652a02238168c4f2b730c8c90dd4a Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 29 Jan 2015 12:02:28 +0000 Subject: VFS: Add a fallthrough flag for marking virtual dentries Add a DCACHE_FALLTHRU flag to indicate that, in a layered filesystem, this is a virtual dentry that covers another one in a lower layer that should be used instead. This may be recorded on medium if directory integration is stored there. The flag can be set with d_set_fallthru() and tested with d_is_fallthru(). Original-author: Valerie Aurora Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/dcache.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'fs/dcache.c') diff --git a/fs/dcache.c b/fs/dcache.c index dc400fd29f4..e33a0934efd 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1659,6 +1659,22 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) } EXPORT_SYMBOL(d_set_d_op); + +/* + * d_set_fallthru - Mark a dentry as falling through to a lower layer + * @dentry - The dentry to mark + * + * Mark a dentry as falling through to the lower layer (as set with + * d_pin_lower()). This flag may be recorded on the medium. + */ +void d_set_fallthru(struct dentry *dentry) +{ + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_FALLTHRU; + spin_unlock(&dentry->d_lock); +} +EXPORT_SYMBOL(d_set_fallthru); + static unsigned d_flags_for_inode(struct inode *inode) { unsigned add_flags = DCACHE_FILE_TYPE; @@ -1691,7 +1707,8 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode) unsigned add_flags = d_flags_for_inode(inode); spin_lock(&dentry->d_lock); - __d_set_type(dentry, add_flags); + dentry->d_flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU); + dentry->d_flags |= add_flags; if (inode) hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); dentry->d_inode = inode; -- cgit v1.2.3-70-g09d2 From 44bdb5e5f6382ba88f7678d6f535f879324522ae Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 29 Jan 2015 12:02:29 +0000 Subject: VFS: Split DCACHE_FILE_TYPE into regular and special types Split DCACHE_FILE_TYPE into DCACHE_REGULAR_TYPE (dentries representing regular files) and DCACHE_SPECIAL_TYPE (representing blockdev, chardev, FIFO and socket files). d_is_reg() and d_is_special() are added to detect these subtypes and d_is_file() is left as the union of the two. This allows a number of places that use S_ISREG(dentry->d_inode->i_mode) to use d_is_reg(dentry) instead. Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/dcache.c | 18 +++++++++++++----- include/linux/dcache.h | 17 ++++++++++++++--- 2 files changed, 27 insertions(+), 8 deletions(-) (limited to 'fs/dcache.c') diff --git a/fs/dcache.c b/fs/dcache.c index e33a0934efd..c71e3732e53 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1677,7 +1677,7 @@ EXPORT_SYMBOL(d_set_fallthru); static unsigned d_flags_for_inode(struct inode *inode) { - unsigned add_flags = DCACHE_FILE_TYPE; + unsigned add_flags = DCACHE_REGULAR_TYPE; if (!inode) return DCACHE_MISS_TYPE; @@ -1690,13 +1690,21 @@ static unsigned d_flags_for_inode(struct inode *inode) else inode->i_opflags |= IOP_LOOKUP; } - } else if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) { - if (unlikely(inode->i_op->follow_link)) + goto type_determined; + } + + if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) { + if (unlikely(inode->i_op->follow_link)) { add_flags = DCACHE_SYMLINK_TYPE; - else - inode->i_opflags |= IOP_NOFOLLOW; + goto type_determined; + } + inode->i_opflags |= IOP_NOFOLLOW; } + if (unlikely(!S_ISREG(inode->i_mode))) + add_flags = DCACHE_SPECIAL_TYPE; + +type_determined: if (unlikely(IS_AUTOMOUNT(inode))) add_flags |= DCACHE_NEED_AUTOMOUNT; return add_flags; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 728f5d31b5e..d8358799c59 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -219,8 +219,9 @@ struct dentry_operations { #define DCACHE_WHITEOUT_TYPE 0x00100000 /* Whiteout dentry (stop pathwalk) */ #define DCACHE_DIRECTORY_TYPE 0x00200000 /* Normal directory */ #define DCACHE_AUTODIR_TYPE 0x00300000 /* Lookupless directory (presumed automount) */ -#define DCACHE_SYMLINK_TYPE 0x00400000 /* Symlink (or fallthru to such) */ -#define DCACHE_FILE_TYPE 0x00500000 /* Other file type (or fallthru to such) */ +#define DCACHE_REGULAR_TYPE 0x00400000 /* Regular file type (or fallthru to such) */ +#define DCACHE_SPECIAL_TYPE 0x00500000 /* Other file type (or fallthru to such) */ +#define DCACHE_SYMLINK_TYPE 0x00600000 /* Symlink (or fallthru to such) */ #define DCACHE_MAY_FREE 0x00800000 #define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */ @@ -455,9 +456,19 @@ static inline bool d_is_symlink(const struct dentry *dentry) return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE; } +static inline bool d_is_reg(const struct dentry *dentry) +{ + return __d_entry_type(dentry) == DCACHE_REGULAR_TYPE; +} + +static inline bool d_is_special(const struct dentry *dentry) +{ + return __d_entry_type(dentry) == DCACHE_SPECIAL_TYPE; +} + static inline bool d_is_file(const struct dentry *dentry) { - return __d_entry_type(dentry) == DCACHE_FILE_TYPE; + return d_is_reg(dentry) || d_is_special(dentry); } static inline bool d_is_negative(const struct dentry *dentry) -- cgit v1.2.3-70-g09d2