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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/coda/cache.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/coda/cache.c')
-rw-r--r-- | fs/coda/cache.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/fs/coda/cache.c b/fs/coda/cache.c new file mode 100644 index 0000000..80072fd --- /dev/null +++ b/fs/coda/cache.c @@ -0,0 +1,120 @@ +/* + * Cache operations for Coda. + * For Linux 2.1: (C) 1997 Carnegie Mellon University + * For Linux 2.3: (C) 2000 Carnegie Mellon University + * + * Carnegie Mellon encourages users of this code to contribute improvements + * to the Coda project http://www.coda.cs.cmu.edu/ <coda@cs.cmu.edu>. + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/stat.h> +#include <linux/errno.h> +#include <asm/uaccess.h> +#include <linux/string.h> +#include <linux/list.h> + +#include <linux/coda.h> +#include <linux/coda_linux.h> +#include <linux/coda_psdev.h> +#include <linux/coda_fs_i.h> +#include <linux/coda_cache.h> + +static atomic_t permission_epoch = ATOMIC_INIT(0); + +/* replace or extend an acl cache hit */ +void coda_cache_enter(struct inode *inode, int mask) +{ + struct coda_inode_info *cii = ITOC(inode); + + cii->c_cached_epoch = atomic_read(&permission_epoch); + if (cii->c_uid != current->fsuid) { + cii->c_uid = current->fsuid; + cii->c_cached_perm = mask; + } else + cii->c_cached_perm |= mask; +} + +/* remove cached acl from an inode */ +void coda_cache_clear_inode(struct inode *inode) +{ + struct coda_inode_info *cii = ITOC(inode); + cii->c_cached_perm = 0; +} + +/* remove all acl caches */ +void coda_cache_clear_all(struct super_block *sb) +{ + struct coda_sb_info *sbi; + + sbi = coda_sbp(sb); + if (!sbi) BUG(); + + atomic_inc(&permission_epoch); +} + + +/* check if the mask has been matched against the acl already */ +int coda_cache_check(struct inode *inode, int mask) +{ + struct coda_inode_info *cii = ITOC(inode); + int hit; + + hit = (mask & cii->c_cached_perm) == mask && + cii->c_uid == current->fsuid && + cii->c_cached_epoch == atomic_read(&permission_epoch); + + return hit; +} + + +/* Purging dentries and children */ +/* The following routines drop dentries which are not + in use and flag dentries which are in use to be + zapped later. + + The flags are detected by: + - coda_dentry_revalidate (for lookups) if the flag is C_PURGE + - coda_dentry_delete: to remove dentry from the cache when d_count + falls to zero + - an inode method coda_revalidate (for attributes) if the + flag is C_VATTR +*/ + +/* this won't do any harm: just flag all children */ +static void coda_flag_children(struct dentry *parent, int flag) +{ + struct list_head *child; + struct dentry *de; + + spin_lock(&dcache_lock); + list_for_each(child, &parent->d_subdirs) + { + de = list_entry(child, struct dentry, d_child); + /* don't know what to do with negative dentries */ + if ( ! de->d_inode ) + continue; + coda_flag_inode(de->d_inode, flag); + } + spin_unlock(&dcache_lock); + return; +} + +void coda_flag_inode_children(struct inode *inode, int flag) +{ + struct dentry *alias_de; + + if ( !inode || !S_ISDIR(inode->i_mode)) + return; + + alias_de = d_find_alias(inode); + if (!alias_de) + return; + coda_flag_children(alias_de, flag); + shrink_dcache_parent(alias_de); + dput(alias_de); +} + |