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author | Barry Naujok <bnaujok@sgi.com> | 2008-05-21 16:41:01 +1000 |
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committer | Niv Sardi <xaiki@debian.org> | 2008-07-28 16:58:36 +1000 |
commit | 5163f95a08cbf058ae16452c2242c5600fedc32e (patch) | |
tree | 5d6b905f7031144a62fb1fa17ba3106d99268003 /fs/xfs/xfs_dir2_block.c | |
parent | 68f34d5107dbace3d14a1c2f060fc8941894879c (diff) | |
download | linux-5163f95a08cbf058ae16452c2242c5600fedc32e.tar.gz linux-5163f95a08cbf058ae16452c2242c5600fedc32e.tar.bz2 linux-5163f95a08cbf058ae16452c2242c5600fedc32e.zip |
[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 <bnaujok@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Diffstat (limited to 'fs/xfs/xfs_dir2_block.c')
-rw-r--r-- | fs/xfs/xfs_dir2_block.c | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/fs/xfs/xfs_dir2_block.c b/fs/xfs/xfs_dir2_block.c index e8a7aca5fe23..98588491cb0e 100644 --- a/fs/xfs/xfs_dir2_block.c +++ b/fs/xfs/xfs_dir2_block.c @@ -643,6 +643,7 @@ xfs_dir2_block_lookup_int( int mid; /* binary search current idx */ xfs_mount_t *mp; /* filesystem mount point */ xfs_trans_t *tp; /* transaction pointer */ + enum xfs_dacmp cmp; /* comparison result */ dp = args->dp; tp = args->trans; @@ -697,20 +698,31 @@ xfs_dir2_block_lookup_int( dep = (xfs_dir2_data_entry_t *) ((char *)block + xfs_dir2_dataptr_to_off(mp, addr)); /* - * Compare, if it's right give back buffer & entry number. + * Compare name and if it's an exact match, return the index + * and buffer. If it's the first case-insensitive match, store + * the index and buffer and continue looking for an exact match. */ - if (dep->namelen == args->namelen && - dep->name[0] == args->name[0] && - memcmp(dep->name, args->name, args->namelen) == 0) { + cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen); + if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) { + args->cmpresult = cmp; *bpp = bp; *entno = mid; - return 0; + if (cmp == XFS_CMP_EXACT) + return 0; } - } while (++mid < be32_to_cpu(btp->count) && be32_to_cpu(blp[mid].hashval) == hash); + } while (++mid < be32_to_cpu(btp->count) && + be32_to_cpu(blp[mid].hashval) == hash); + + ASSERT(args->oknoent); + /* + * Here, we can only be doing a lookup (not a rename or replace). + * If a case-insensitive match was found earlier, return success. + */ + if (args->cmpresult == XFS_CMP_CASE) + return 0; /* * No match, release the buffer and return ENOENT. */ - ASSERT(args->oknoent); xfs_da_brelse(tp, bp); return XFS_ERROR(ENOENT); } @@ -1033,6 +1045,7 @@ xfs_dir2_sf_to_block( xfs_dir2_sf_t *sfp; /* shortform structure */ __be16 *tagp; /* end of data entry */ xfs_trans_t *tp; /* transaction pointer */ + struct xfs_name name; xfs_dir2_trace_args("sf_to_block", args); dp = args->dp; @@ -1187,8 +1200,10 @@ xfs_dir2_sf_to_block( tagp = xfs_dir2_data_entry_tag_p(dep); *tagp = cpu_to_be16((char *)dep - (char *)block); xfs_dir2_data_log_entry(tp, bp, dep); - blp[2 + i].hashval = cpu_to_be32(xfs_da_hashname( - (char *)sfep->name, sfep->namelen)); + name.name = sfep->name; + name.len = sfep->namelen; + blp[2 + i].hashval = cpu_to_be32(mp->m_dirnameops-> + hashname(&name)); blp[2 + i].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp, (char *)dep - (char *)block)); offset = (int)((char *)(tagp + 1) - (char *)block); |