| Sage Weil | 0dee3c2 | 2009-10-06 11:31:06 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Some non-inline ceph helpers |
| 3 | */ |
| 4 | #include "types.h" |
| 5 | |
| Sage Weil | 752727a | 2009-10-09 16:38:45 -0700 | [diff] [blame^] | 6 | /* |
| 7 | * return true if @layout appears to be valid |
| 8 | */ |
| 9 | int ceph_file_layout_is_valid(const struct ceph_file_layout *layout) |
| 10 | { |
| 11 | __u32 su = le32_to_cpu(layout->fl_stripe_unit); |
| 12 | __u32 sc = le32_to_cpu(layout->fl_stripe_count); |
| 13 | __u32 os = le32_to_cpu(layout->fl_object_size); |
| 14 | |
| 15 | /* stripe unit, object size must be non-zero, 64k increment */ |
| 16 | if (!su || (su & (CEPH_MIN_STRIPE_UNIT-1))) |
| 17 | return 0; |
| 18 | if (!os || (os & (CEPH_MIN_STRIPE_UNIT-1))) |
| 19 | return 0; |
| 20 | /* object size must be a multiple of stripe unit */ |
| 21 | if (os < su || os % su) |
| 22 | return 0; |
| 23 | /* stripe count must be non-zero */ |
| 24 | if (!sc) |
| 25 | return 0; |
| 26 | return 1; |
| 27 | } |
| 28 | |
| 29 | |
| Sage Weil | 0dee3c2 | 2009-10-06 11:31:06 -0700 | [diff] [blame] | 30 | int ceph_flags_to_mode(int flags) |
| 31 | { |
| 32 | #ifdef O_DIRECTORY /* fixme */ |
| 33 | if ((flags & O_DIRECTORY) == O_DIRECTORY) |
| 34 | return CEPH_FILE_MODE_PIN; |
| 35 | #endif |
| 36 | #ifdef O_LAZY |
| 37 | if (flags & O_LAZY) |
| 38 | return CEPH_FILE_MODE_LAZY; |
| 39 | #endif |
| 40 | if ((flags & O_APPEND) == O_APPEND) |
| 41 | flags |= O_WRONLY; |
| 42 | |
| 43 | flags &= O_ACCMODE; |
| 44 | if ((flags & O_RDWR) == O_RDWR) |
| 45 | return CEPH_FILE_MODE_RDWR; |
| 46 | if ((flags & O_WRONLY) == O_WRONLY) |
| 47 | return CEPH_FILE_MODE_WR; |
| 48 | return CEPH_FILE_MODE_RD; |
| 49 | } |
| 50 | |
| 51 | int ceph_caps_for_mode(int mode) |
| 52 | { |
| 53 | switch (mode) { |
| 54 | case CEPH_FILE_MODE_PIN: |
| 55 | return CEPH_CAP_PIN; |
| 56 | case CEPH_FILE_MODE_RD: |
| 57 | return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED | |
| 58 | CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE; |
| 59 | case CEPH_FILE_MODE_RDWR: |
| 60 | return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED | |
| 61 | CEPH_CAP_FILE_EXCL | |
| 62 | CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE | |
| 63 | CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER | |
| 64 | CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL | |
| 65 | CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL; |
| 66 | case CEPH_FILE_MODE_WR: |
| 67 | return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED | |
| 68 | CEPH_CAP_FILE_EXCL | |
| 69 | CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER | |
| 70 | CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL | |
| 71 | CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL; |
| 72 | } |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | /* Name hashing routines. Initial hash value */ |
| 77 | /* Hash courtesy of the R5 hash in reiserfs modulo sign bits */ |
| 78 | #define ceph_init_name_hash() 0 |
| 79 | |
| 80 | /* partial hash update function. Assume roughly 4 bits per character */ |
| 81 | static unsigned long ceph_partial_name_hash(unsigned long c, |
| 82 | unsigned long prevhash) |
| 83 | { |
| 84 | return (prevhash + (c << 4) + (c >> 4)) * 11; |
| 85 | } |
| 86 | |
| 87 | /* |
| 88 | * Finally: cut down the number of bits to a int value (and try to avoid |
| 89 | * losing bits) |
| 90 | */ |
| 91 | static unsigned long ceph_end_name_hash(unsigned long hash) |
| 92 | { |
| 93 | return hash & 0xffffffff; |
| 94 | } |
| 95 | |
| 96 | /* Compute the hash for a name string. */ |
| 97 | unsigned int ceph_full_name_hash(const char *name, unsigned int len) |
| 98 | { |
| 99 | unsigned long hash = ceph_init_name_hash(); |
| 100 | while (len--) |
| 101 | hash = ceph_partial_name_hash(*name++, hash); |
| 102 | return ceph_end_name_hash(hash); |
| 103 | } |
| 104 | |