diff options
Diffstat (limited to 'source/smbd/fileio.c')
| -rw-r--r-- | source/smbd/fileio.c | 87 |
1 files changed, 86 insertions, 1 deletions
diff --git a/source/smbd/fileio.c b/source/smbd/fileio.c index fd660f40d08..06bce01e78f 100644 --- a/source/smbd/fileio.c +++ b/source/smbd/fileio.c @@ -256,6 +256,18 @@ nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n", if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) { + /* ASCII art.... JRA. + + +--------------+----- + | Cached data | Rest of allocated cache buffer.... + +--------------+----- + + +-------------------+ + | Data to write | + +-------------------+ + + */ + /* * Start of write overlaps or abutts the existing data. */ @@ -305,6 +317,18 @@ nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n", } else if ((pos < wcp->offset) && (pos + n > wcp->offset) && (pos + n <= wcp->offset + wcp->alloc_size)) { + /* ASCII art.... JRA. + + +---------------+ + | Cache buffer | + +---------------+ + + +-------------------+ + | Data to write | + +-------------------+ + + */ + /* * End of write overlaps the existing data. */ @@ -350,6 +374,20 @@ nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n", (pos > wcp->offset + wcp->data_size) && (pos < wcp->offset + wcp->alloc_size) ) { + /* ASCII art.... JRA. + + End of file ---->| + + +---------------+---------------+ + | Cached data | Cache buffer | + +---------------+---------------+ + + +-------------------+ + | Data to write | + +-------------------+ + + */ + /* * Non-contiguous write part of which fits within * the cache buffer and is extending the file @@ -413,7 +451,41 @@ nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n", } else { - /* + /* ASCII art..... JRA. + + Case 1). + + +---------------+---------------+ + | Cached data | Cache buffer | + +---------------+---------------+ + + +-------------------+ + | Data to write | + +-------------------+ + + Case 2). + + +---------------+---------------+ + | Cached data | Cache buffer | + +---------------+---------------+ + + +-------------------+ + | Data to write | + +-------------------+ + + Case 3). + + +---------------+---------------+ + | Cached data | Cache buffer | + +---------------+---------------+ + + +-----------------------------------------------------+ + | Data to write | + +-----------------------------------------------------+ + + */ + + /* * Write is bigger than buffer, or there is no overlap on the * low or high ends. */ @@ -440,6 +512,19 @@ len = %u\n",fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigne } else { ssize_t ret = real_write_file(fsp, data, pos, n); + /* + * If the write overlaps the entire cache, then + * discard the current contents of the cache. + * Fix from Rasmus Borup Hansen rbh@math.ku.dk. + */ + + if ((pos <= wcp->offset) && + (pos + n >= wcp->offset + wcp->data_size) ) { + DEBUG(9,("write_file: discarding overwritten write \ +cache: fd = %d, off=%.0f, size=%u\n", fsp->fd, (double)wcp->offset, (unsigned int)wcp->data_size )); + wcp->data_size = 0; + } + DO_PROFILE_INC(writecache_direct_writes); if (ret == -1) return ret; |