From 5163f95a08cbf058ae16452c2242c5600fedc32e Mon Sep 17 00:00:00 2001 From: Barry Naujok Date: Wed, 21 May 2008 16:41:01 +1000 Subject: [XFS] Name operation vector for hash and compare Adds two pieces of functionality for the basis of case-insensitive support in XFS: 1. A comparison result enumerated type: xfs_dacmp. It represents an exact match, case-insensitive match or no match at all. This patch only implements different and exact results. 2. xfs_nameops vector for specifying how to perform the hash generation of filenames and comparision methods. In this patch the hash vector points to the existing xfs_da_hashname function and the comparison method does a length compare, and if the same, does a memcmp and return the xfs_dacmp result. All filename functions that use the hash (create, lookup remove, rename, etc) now use the xfs_nameops.hashname function and all directory lookup functions also use the xfs_nameops.compname function. The lookup functions also handle case-insensitive results even though the default comparison function cannot return that. And important aspect of the lookup functions is that an exact match always has precedence over a case-insensitive. So while a case-insensitive match is found, we have to keep looking just in case there is an exact match. In the meantime, the info for the first case-insensitive match is retained if no exact match is found. SGI-PV: 981519 SGI-Modid: xfs-linux-melb:xfs-kern:31205a Signed-off-by: Barry Naujok Signed-off-by: Christoph Hellwig --- fs/xfs/xfs_da_btree.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'fs/xfs/xfs_da_btree.h') diff --git a/fs/xfs/xfs_da_btree.h b/fs/xfs/xfs_da_btree.h index 7facf86..e64c692 100644 --- a/fs/xfs/xfs_da_btree.h +++ b/fs/xfs/xfs_da_btree.h @@ -99,6 +99,15 @@ typedef struct xfs_da_node_entry xfs_da_node_entry_t; *========================================================================*/ /* + * Search comparison results + */ +enum xfs_dacmp { + XFS_CMP_DIFFERENT, /* names are completely different */ + XFS_CMP_EXACT, /* names are exactly the same */ + XFS_CMP_CASE /* names are same but differ in case */ +}; + +/* * Structure to ease passing around component names. */ typedef struct xfs_da_args { @@ -127,6 +136,7 @@ typedef struct xfs_da_args { unsigned char rename; /* T/F: this is an atomic rename op */ unsigned char addname; /* T/F: this is an add operation */ unsigned char oknoent; /* T/F: ok to return ENOENT, else die */ + enum xfs_dacmp cmpresult; /* name compare result for lookups */ } xfs_da_args_t; /* @@ -201,6 +211,14 @@ typedef struct xfs_da_state { (uint)(XFS_DA_LOGOFF(BASE, ADDR)), \ (uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1) +/* + * Name ops for directory and/or attr name operations + */ +struct xfs_nameops { + xfs_dahash_t (*hashname)(struct xfs_name *); + enum xfs_dacmp (*compname)(struct xfs_da_args *, const char *, int); +}; + #ifdef __KERNEL__ /*======================================================================== @@ -249,6 +267,10 @@ int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno, xfs_dabuf_t *dead_buf); uint xfs_da_hashname(const uchar_t *name_string, int name_length); +enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args, + const char *name, int len); + + xfs_da_state_t *xfs_da_state_alloc(void); void xfs_da_state_free(xfs_da_state_t *state); -- cgit v1.1