Version 1.9.
read/write to a files_struct
Copyright (C) Andrew Tridgell 1992-1998
+ Copyright (C) Jeremy Allison 2000-2002. - write cache.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "includes.h"
-extern int DEBUGLEVEL;
-
static BOOL setup_write_cache(files_struct *, SMB_OFF_T);
/****************************************************************************
-seek a file. Try to avoid the seek if possible
+ Read from write cache if we can.
****************************************************************************/
-SMB_OFF_T seek_file(files_struct *fsp,SMB_OFF_T pos)
+static BOOL read_from_write_cache(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
{
- SMB_OFF_T offset = 0;
- SMB_OFF_T seek_ret;
-
- if (fsp->print_file && lp_postscript(fsp->conn->service))
- offset = 3;
+ write_cache *wcp = fsp->wcp;
- seek_ret = fsp->conn->vfs_ops.lseek(fsp->fd,pos+offset,SEEK_SET);
+ if(!wcp) {
+ return False;
+ }
- /*
- * We want to maintain the fiction that we can seek
- * on a fifo for file system purposes. This allows
- * people to set up UNIX fifo's that feed data to Windows
- * applications. JRA.
- */
+ if( n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size) {
+ return False;
+ }
- if((seek_ret == -1) && (errno == ESPIPE)) {
- seek_ret = pos+offset;
- errno = 0;
- }
+ memcpy(data, wcp->data + (pos - wcp->offset), n);
- if((seek_ret == -1) || (seek_ret != pos+offset)) {
- DEBUG(0,("seek_file: sys_lseek failed. Error was %s\n", strerror(errno) ));
- fsp->pos = -1;
- return -1;
- }
+ DO_PROFILE_INC(writecache_read_hits);
- fsp->pos = seek_ret - offset;
-
- DEBUG(10,("seek_file: requested pos = %.0f, new pos = %.0f\n",
- (double)(pos+offset), (double)fsp->pos ));
-
- return(fsp->pos);
+ return True;
}
/****************************************************************************
- Read from write cache if we can.
+ Read from a file.
****************************************************************************/
-static unsigned int cache_read_hits;
-
-BOOL read_from_write_cache(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
+ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
{
- write_cache *wcp = fsp->wcp;
-
- if(!wcp)
- return False;
-
- if(n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size)
- return False;
+ ssize_t ret=0,readret;
+
+ /* you can't read from print files */
+ if (fsp->print_file) {
+ return -1;
+ }
+
+ /*
+ * Serve from write cache if we can.
+ */
+
+ if(read_from_write_cache(fsp, data, pos, n)) {
+ fsp->fh->pos = pos + n;
+ fsp->fh->position_information = fsp->fh->pos;
+ return n;
+ }
+
+ flush_write_cache(fsp, READ_FLUSH);
+
+ fsp->fh->pos = pos;
+
+ if (n > 0) {
+#ifdef DMF_FIX
+ int numretries = 3;
+tryagain:
+ readret = SMB_VFS_PREAD(fsp,fsp->fh->fd,data,n,pos);
+
+ if (readret == -1) {
+ if ((errno == EAGAIN) && numretries) {
+ DEBUG(3,("read_file EAGAIN retry in 10 seconds\n"));
+ (void)sleep(10);
+ --numretries;
+ goto tryagain;
+ }
+ return -1;
+ }
+#else /* NO DMF fix. */
+ readret = SMB_VFS_PREAD(fsp,fsp->fh->fd,data,n,pos);
+
+ if (readret == -1) {
+ return -1;
+ }
+#endif
+ if (readret > 0) {
+ ret += readret;
+ }
+ }
- memcpy(data, wcp->data + (pos - wcp->offset), n);
+ DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
+ fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
- cache_read_hits++;
+ fsp->fh->pos += ret;
+ fsp->fh->position_information = fsp->fh->pos;
- return True;
+ return(ret);
}
+/* how many write cache buffers have been allocated */
+static unsigned int allocated_write_caches;
+
/****************************************************************************
-read from a file
+ *Really* write to a file.
****************************************************************************/
-ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
+static ssize_t real_write_file(files_struct *fsp,const char *data, SMB_OFF_T pos, size_t n)
{
- ssize_t ret=0,readret;
-
- /*
- * Serve from write cache if we can.
- */
- if(read_from_write_cache(fsp, data, pos, n))
- return n;
-
- flush_write_cache(fsp, READ_FLUSH);
-
- if (seek_file(fsp,pos) == -1) {
- DEBUG(3,("read_file: Failed to seek to %.0f\n",(double)pos));
- return(ret);
- }
-
- if (n > 0) {
- readret = fsp->conn->vfs_ops.read(fsp->fd,data,n);
- if (readret > 0) ret += readret;
- }
+ ssize_t ret;
+
+ if (pos == -1) {
+ ret = vfs_write_data(fsp, data, n);
+ } else {
+ fsp->fh->pos = pos;
+ if (pos && lp_strict_allocate(SNUM(fsp->conn))) {
+ if (vfs_fill_sparse(fsp, pos) == -1) {
+ return -1;
+ }
+ }
+ ret = vfs_pwrite_data(fsp, data, n, pos);
+ }
+
+ DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
+ fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
+
+ if (ret != -1) {
+ fsp->fh->pos += ret;
+
+ /*
+ * It turns out that setting the last write time from a Windows
+ * client stops any subsequent writes from updating the write time.
+ * Doing this after the write gives a race condition here where
+ * a stat may see the changed write time before we reset it here,
+ * but it's cheaper than having to store the write time in shared
+ * memory and look it up using dev/inode across all running smbd's.
+ * The 99% solution will hopefully be good enough in this case. JRA.
+ */
+
+ if (!null_timespec(fsp->pending_modtime)) {
+ set_filetime(fsp->conn, fsp->fsp_name, fsp->pending_modtime);
+
+ /* If we didn't get the "set modtime" call ourselves, we must
+ store the last write time to restore on close. JRA. */
+ if (!fsp->pending_modtime_owner) {
+ fsp->last_write_time = timespec_current();
+ }
+ }
+
+/* Yes - this is correct - writes don't update this. JRA. */
+/* Found by Samba4 tests. */
+#if 0
+ fsp->position_information = fsp->pos;
+#endif
+ }
- return(ret);
+ return ret;
}
-/* Write cache static counters. */
-
-static unsigned int abutted_writes;
-static unsigned int total_writes;
-static unsigned int non_oplock_writes;
-static unsigned int direct_writes;
-static unsigned int init_writes;
-static unsigned int flushed_writes;
-static unsigned int num_perfect_writes;
-static unsigned int flush_reasons[NUM_FLUSH_REASONS];
-
-/* how many write cache buffers have been allocated */
-static unsigned int allocated_write_caches;
-static unsigned int num_write_caches;
-
/****************************************************************************
- *Really* write to a file
+ File size cache change.
+ Updates size on disk but doesn't flush the cache.
****************************************************************************/
-static ssize_t real_write_file(files_struct *fsp,char *data,SMB_OFF_T pos, size_t n)
+static int wcp_file_size_change(files_struct *fsp)
{
- if ((pos != -1) && (seek_file(fsp,pos) == -1))
- return -1;
-
- return write_data(fsp->fd,data,n);
+ int ret;
+ write_cache *wcp = fsp->wcp;
+
+ wcp->file_size = wcp->offset + wcp->data_size;
+ ret = SMB_VFS_FTRUNCATE(fsp, fsp->fh->fd, wcp->file_size);
+ if (ret == -1) {
+ DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f error %s\n",
+ fsp->fsp_name, (double)wcp->file_size, strerror(errno) ));
+ }
+ return ret;
}
/****************************************************************************
-write to a file
+ Write to a file.
****************************************************************************/
-ssize_t write_file(files_struct *fsp, char *data, SMB_OFF_T pos, size_t n)
+ssize_t write_file(files_struct *fsp, const char *data, SMB_OFF_T pos, size_t n)
{
- write_cache *wcp = fsp->wcp;
- ssize_t total_written = 0;
- int write_path = -1;
-
- if (!fsp->can_write) {
- errno = EPERM;
- return(0);
- }
-
- if (!fsp->modified) {
- SMB_STRUCT_STAT st;
- fsp->modified = True;
-
- if (fsp->conn->vfs_ops.fstat(fsp->fd,&st) == 0) {
- int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
- if (MAP_ARCHIVE(fsp->conn) && !IS_DOS_ARCHIVE(dosmode)) {
- file_chmod(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st);
- }
-
- /*
- * If this is the first write and we have an exclusive oplock then setup
- * the write cache.
- */
-
- if ((fsp->oplock_type == EXCLUSIVE_OPLOCK) && !wcp) {
- setup_write_cache(fsp, st.st_size);
- wcp = fsp->wcp;
- }
- }
- }
-
- total_writes++;
- if (!fsp->oplock_type) {
- non_oplock_writes++;
- }
-
- /*
- * If this file is level II oplocked then we need
- * to grab the shared memory lock and inform all
- * other files with a level II lock that they need
- * to flush their read caches. We keep the lock over
- * the shared memory area whilst doing this.
- */
-
- if (LEVEL_II_OPLOCK_TYPE(fsp->oplock_type)) {
- share_mode_entry *share_list = NULL;
- pid_t pid = getpid();
- int token = -1;
- int num_share_modes = 0;
- int i;
-
- if (lock_share_entry_fsp(fsp) == False) {
- DEBUG(0,("write_file: failed to lock share mode entry for file %s.\n", fsp->fsp_name ));
- }
-
- num_share_modes = get_share_modes(fsp->conn, fsp->dev, fsp->inode, &share_list);
-
- for(i = 0; i < num_share_modes; i++) {
- share_mode_entry *share_entry = &share_list[i];
-
- /*
- * As there could have been multiple writes waiting at the lock_share_entry
- * gate we may not be the first to enter. Hence the state of the op_types
- * in the share mode entries may be partly NO_OPLOCK and partly LEVEL_II
- * oplock. It will do no harm to re-send break messages to those smbd's
- * that are still waiting their turn to remove their LEVEL_II state, and
- * also no harm to ignore existing NO_OPLOCK states. JRA.
- */
-
- if (share_entry->op_type == NO_OPLOCK)
- continue;
-
- /* Paranoia .... */
- if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
- DEBUG(0,("write_file: PANIC. share mode entry %d is an exlusive oplock !\n", i ));
- abort();
- }
-
- /*
- * Check if this is a file we have open (including the
- * file we've been called to do write_file on. If so
- * then break it directly without releasing the lock.
- */
-
- if (pid == share_entry->pid) {
- files_struct *new_fsp = file_find_dit(fsp->dev, fsp->inode, &share_entry->time);
-
- /* Paranoia check... */
- if(new_fsp == NULL) {
- DEBUG(0,("write_file: PANIC. share mode entry %d is not a local file !\n", i ));
- abort();
- }
- oplock_break_level2(new_fsp, True, token);
-
- } else {
-
- /*
- * This is a remote file and so we send an asynchronous
- * message.
- */
-
- request_oplock_break(share_entry, fsp->dev, fsp->inode);
- }
- }
-
- free((char *)share_list);
- unlock_share_entry_fsp(fsp);
- }
-
- /* Paranoia check... */
- if (LEVEL_II_OPLOCK_TYPE(fsp->oplock_type)) {
- DEBUG(0,("write_file: PANIC. File %s still has a level II oplock.\n", fsp->fsp_name));
- abort();
- }
-
- if (total_writes % 500 == 0) {
- DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u flushes=%u total=%u \
+ write_cache *wcp = fsp->wcp;
+ ssize_t total_written = 0;
+ int write_path = -1;
+
+ if (fsp->print_file) {
+ fstring sharename;
+ uint32 jobid;
+
+ if (!rap_to_pjobid(fsp->rap_print_jobid, sharename, &jobid)) {
+ DEBUG(3,("write_file: Unable to map RAP jobid %u to jobid.\n",
+ (unsigned int)fsp->rap_print_jobid ));
+ errno = EBADF;
+ return -1;
+ }
+
+ return print_job_write(SNUM(fsp->conn), jobid, data, pos, n);
+ }
+
+ if (!fsp->can_write) {
+ errno = EPERM;
+ return -1;
+ }
+
+ if (!fsp->modified) {
+ SMB_STRUCT_STAT st;
+ fsp->modified = True;
+
+ if (SMB_VFS_FSTAT(fsp,fsp->fh->fd,&st) == 0) {
+ int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
+ if ((lp_store_dos_attributes(SNUM(fsp->conn)) || MAP_ARCHIVE(fsp->conn)) && !IS_DOS_ARCHIVE(dosmode)) {
+ file_set_dosmode(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st, False);
+ }
+
+ /*
+ * If this is the first write and we have an exclusive oplock then setup
+ * the write cache.
+ */
+
+ if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
+ setup_write_cache(fsp, st.st_size);
+ wcp = fsp->wcp;
+ }
+ }
+ }
+
+#ifdef WITH_PROFILE
+ DO_PROFILE_INC(writecache_total_writes);
+ if (!fsp->oplock_type) {
+ DO_PROFILE_INC(writecache_non_oplock_writes);
+ }
+#endif
+
+ /*
+ * If this file is level II oplocked then we need
+ * to grab the shared memory lock and inform all
+ * other files with a level II lock that they need
+ * to flush their read caches. We keep the lock over
+ * the shared memory area whilst doing this.
+ */
+
+ release_level_2_oplocks_on_change(fsp);
+
+#ifdef WITH_PROFILE
+ if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
+ DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
- init_writes, abutted_writes, flushed_writes, total_writes, non_oplock_writes,
- allocated_write_caches,
- num_write_caches, direct_writes, num_perfect_writes, cache_read_hits ));
-
- DEBUG(3,("WRITECACHE: SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
- flush_reasons[SEEK_FLUSH],
- flush_reasons[READ_FLUSH],
- flush_reasons[WRITE_FLUSH],
- flush_reasons[READRAW_FLUSH],
- flush_reasons[OPLOCK_RELEASE_FLUSH],
- flush_reasons[CLOSE_FLUSH],
- flush_reasons[SYNC_FLUSH] ));
- }
-
- if(!wcp) {
- direct_writes++;
- return real_write_file(fsp, data, pos, n);
- }
-
- DEBUG(9,("write_file(fd=%d pos=%d size=%d) wofs=%d wsize=%d\n",
- fsp->fd, (int)pos, (int)n, (int)wcp->offset, (int)wcp->data_size));
-
- /*
- * If we have active cache and it isn't contiguous then we flush.
- * NOTE: There is a small problem with running out of disk ....
- */
-
- if (wcp->data_size) {
-
- BOOL cache_flush_needed = False;
-
- if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
+ profile_p->writecache_init_writes,
+ profile_p->writecache_abutted_writes,
+ profile_p->writecache_total_writes,
+ profile_p->writecache_non_oplock_writes,
+ profile_p->writecache_allocated_write_caches,
+ profile_p->writecache_num_write_caches,
+ profile_p->writecache_direct_writes,
+ profile_p->writecache_num_perfect_writes,
+ profile_p->writecache_read_hits ));
+
+ DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
+ profile_p->writecache_flushed_writes[SEEK_FLUSH],
+ profile_p->writecache_flushed_writes[READ_FLUSH],
+ profile_p->writecache_flushed_writes[WRITE_FLUSH],
+ profile_p->writecache_flushed_writes[READRAW_FLUSH],
+ profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
+ profile_p->writecache_flushed_writes[CLOSE_FLUSH],
+ profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
+ }
+#endif
+
+ if(!wcp) {
+ DO_PROFILE_INC(writecache_direct_writes);
+ total_written = real_write_file(fsp, data, pos, n);
+ return total_written;
+ }
+
+ DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f wcp->data_size=%u\n",
+ fsp->fsp_name, fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size));
+
+ fsp->fh->pos = pos + n;
+
+ /*
+ * If we have active cache and it isn't contiguous then we flush.
+ * NOTE: There is a small problem with running out of disk ....
+ */
+
+ if (wcp->data_size) {
+ BOOL cache_flush_needed = False;
+
+ if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
- /*
- * Start of write overlaps or abutts the existing data.
- */
+ /* ASCII art.... JRA.
- size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
+ +--------------+-----
+ | Cached data | Rest of allocated cache buffer....
+ +--------------+-----
- memcpy(wcp->data + (pos - wcp->offset), data, data_used);
+ +-------------------+
+ | Data to write |
+ +-------------------+
- /*
- * Update the current buffer size with the new data.
- */
+ */
- if(pos + data_used > wcp->offset + wcp->data_size)
- wcp->data_size = pos + data_used - wcp->offset;
+ /*
+ * Start of write overlaps or abutts the existing data.
+ */
- /*
- * If we used all the data then
- * return here.
- */
+ size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
- if(n == data_used)
- return n;
- else
- cache_flush_needed = True;
+ memcpy(wcp->data + (pos - wcp->offset), data, data_used);
- /*
- * Move the start of data forward by the amount used,
- * cut down the amount left by the same amount.
- */
+ /*
+ * Update the current buffer size with the new data.
+ */
- data += data_used;
- pos += data_used;
- n -= data_used;
+ if(pos + data_used > wcp->offset + wcp->data_size) {
+ wcp->data_size = pos + data_used - wcp->offset;
+ }
- abutted_writes++;
- total_written = data_used;
+ /*
+ * Update the file size if changed.
+ */
- write_path = 1;
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
- } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
- (pos + n <= wcp->offset + wcp->alloc_size)) {
+ /*
+ * If we used all the data then
+ * return here.
+ */
- /*
- * End of write overlaps the existing data.
- */
+ if(n == data_used) {
+ return n;
+ } else {
+ cache_flush_needed = True;
+ }
+ /*
+ * Move the start of data forward by the amount used,
+ * cut down the amount left by the same amount.
+ */
- size_t data_used = pos + n - wcp->offset;
+ data += data_used;
+ pos += data_used;
+ n -= data_used;
- memcpy(wcp->data, data + n - data_used, data_used);
+ DO_PROFILE_INC(writecache_abutted_writes);
+ total_written = data_used;
- /*
- * Update the current buffer size with the new data.
- */
+ write_path = 1;
- if(pos + n > wcp->offset + wcp->data_size)
- wcp->data_size = pos + n - wcp->offset;
+ } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
+ (pos + n <= wcp->offset + wcp->alloc_size)) {
- /*
- * We don't need to move the start of data, but we
- * cut down the amount left by the amount used.
- */
+ /* ASCII art.... JRA.
- n -= data_used;
+ +---------------+
+ | Cache buffer |
+ +---------------+
- /*
- * We cannot have used all the data here.
- */
+ +-------------------+
+ | Data to write |
+ +-------------------+
- cache_flush_needed = True;
+ */
- abutted_writes++;
- total_written = data_used;
+ /*
+ * End of write overlaps the existing data.
+ */
- write_path = 2;
+ size_t data_used = pos + n - wcp->offset;
- } else if ( (pos >= wcp->file_size) &&
- (pos > wcp->offset + wcp->data_size) &&
- (pos < wcp->offset + wcp->alloc_size) ) {
+ memcpy(wcp->data, data + n - data_used, data_used);
- /*
- * Non-contiguous write part of which fits within
- * the cache buffer and is extending the file.
- */
+ /*
+ * Update the current buffer size with the new data.
+ */
- size_t data_used;
+ if(pos + n > wcp->offset + wcp->data_size) {
+ wcp->data_size = pos + n - wcp->offset;
+ }
- if(pos + n <= wcp->offset + wcp->alloc_size)
- data_used = n;
- else
- data_used = wcp->offset + wcp->alloc_size - pos;
+ /*
+ * Update the file size if changed.
+ */
- /*
- * Fill in the non-continuous area with zeros.
- */
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
- memset(wcp->data + wcp->data_size, '\0',
- pos - (wcp->offset + wcp->data_size) );
+ /*
+ * We don't need to move the start of data, but we
+ * cut down the amount left by the amount used.
+ */
- memcpy(wcp->data + (pos - wcp->offset), data, data_used);
+ n -= data_used;
- /*
- * Update the current buffer size with the new data.
- */
+ /*
+ * We cannot have used all the data here.
+ */
- if(pos + data_used > wcp->offset + wcp->data_size)
- wcp->data_size = pos + data_used - wcp->offset;
+ cache_flush_needed = True;
- /*
- * Update the known file length.
- */
+ DO_PROFILE_INC(writecache_abutted_writes);
+ total_written = data_used;
- wcp->file_size = wcp->offset + wcp->data_size;
+ write_path = 2;
-#if 0
- if (set_filelen(fsp->fd, wcp->file_size) == -1) {
- DEBUG(0,("write_file: error %s in setting file to length %.0f\n",
- strerror(errno), (double)wcp->file_size ));
- return -1;
- }
-#endif
+ } else if ( (pos >= wcp->file_size) &&
+ (wcp->offset + wcp->data_size == wcp->file_size) &&
+ (pos > wcp->offset + wcp->data_size) &&
+ (pos < wcp->offset + wcp->alloc_size) ) {
+
+ /* ASCII art.... JRA.
+
+ End of file ---->|
- /*
- * If we used all the data then
- * return here.
- */
+ +---------------+---------------+
+ | Cached data | Cache buffer |
+ +---------------+---------------+
- if(n == data_used)
- return n;
- else
- cache_flush_needed = True;
+ +-------------------+
+ | Data to write |
+ +-------------------+
- /*
- * Move the start of data forward by the amount used,
- * cut down the amount left by the same amount.
- */
+ */
- data += data_used;
- pos += data_used;
- n -= data_used;
+ /*
+ * Non-contiguous write part of which fits within
+ * the cache buffer and is extending the file
+ * and the cache contents reflect the current
+ * data up to the current end of the file.
+ */
- abutted_writes++;
- total_written = data_used;
+ size_t data_used;
- write_path = 3;
+ if(pos + n <= wcp->offset + wcp->alloc_size) {
+ data_used = n;
+ } else {
+ data_used = wcp->offset + wcp->alloc_size - pos;
+ }
- } else {
+ /*
+ * Fill in the non-continuous area with zeros.
+ */
- /*
- * Write is bigger than buffer, or there is no overlap on the
- * low or high ends.
- */
+ memset(wcp->data + wcp->data_size, '\0',
+ pos - (wcp->offset + wcp->data_size) );
- DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
-len = %u\n",fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
+ memcpy(wcp->data + (pos - wcp->offset), data, data_used);
- /*
- * Update the file size if needed.
- */
+ /*
+ * Update the current buffer size with the new data.
+ */
- if(pos + n > wcp->file_size)
- wcp->file_size = pos + n;
+ if(pos + data_used > wcp->offset + wcp->data_size) {
+ wcp->data_size = pos + data_used - wcp->offset;
+ }
- /*
- * If write would fit in the cache, and is larger than
- * the data already in the cache, flush the cache and
- * preferentially copy the data new data into it. Otherwise
- * just write the data directly.
- */
+ /*
+ * Update the file size if changed.
+ */
- if ( n <= wcp->alloc_size && n > wcp->data_size) {
- cache_flush_needed = True;
- } else {
- direct_writes++;
- return real_write_file(fsp, data, pos, n);
- }
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
- write_path = 4;
+ /*
+ * If we used all the data then
+ * return here.
+ */
- }
+ if(n == data_used) {
+ return n;
+ } else {
+ cache_flush_needed = True;
+ }
- if(wcp->data_size > wcp->file_size)
- wcp->file_size = wcp->data_size;
+ /*
+ * Move the start of data forward by the amount used,
+ * cut down the amount left by the same amount.
+ */
- if (cache_flush_needed) {
- flushed_writes++;
+ data += data_used;
+ pos += data_used;
+ n -= data_used;
- DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
+ DO_PROFILE_INC(writecache_abutted_writes);
+ total_written = data_used;
+
+ write_path = 3;
+
+ } else if ( (pos >= wcp->file_size) &&
+ (n == 1) &&
+ (pos < wcp->offset + 2*wcp->alloc_size) &&
+ (wcp->file_size == wcp->offset + wcp->data_size)) {
+
+ /*
+ +---------------+
+ | Cached data |
+ +---------------+
+
+ +--------+
+ | 1 Byte |
+ +--------+
+
+ MS-Office seems to do this a lot to determine if there's enough
+ space on the filesystem to write a new file.
+ */
+
+ SMB_BIG_UINT new_start = wcp->offset + wcp->data_size;
+
+ flush_write_cache(fsp, WRITE_FLUSH);
+ wcp->offset = new_start;
+ wcp->data_size = pos - new_start + 1;
+ memset(wcp->data, '\0', wcp->data_size);
+ memcpy(wcp->data + wcp->data_size-1, data, 1);
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+
+ return 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.
+ */
+
+ DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
+len = %u\n",fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
+
+ /*
+ * If write would fit in the cache, and is larger than
+ * the data already in the cache, flush the cache and
+ * preferentially copy the data new data into it. Otherwise
+ * just write the data directly.
+ */
+
+ if ( n <= wcp->alloc_size && n > wcp->data_size) {
+ cache_flush_needed = True;
+ } 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->fh->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
+ wcp->data_size = 0;
+ }
+
+ DO_PROFILE_INC(writecache_direct_writes);
+ if (ret == -1) {
+ return ret;
+ }
+
+ if (pos + ret > wcp->file_size) {
+ wcp->file_size = pos + ret;
+ }
+
+ return ret;
+ }
+
+ write_path = 4;
+
+ }
+
+ if (cache_flush_needed) {
+ DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
- write_path, fsp->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
- (double)wcp->offset, (unsigned int)wcp->data_size ));
-
- flush_write_cache(fsp, WRITE_FLUSH);
- }
- }
-
- /*
- * If the write request is bigger than the cache
- * size, write it all out.
- */
-
- if (n > wcp->alloc_size ) {
- if(real_write_file(fsp, data, pos, n) == -1)
- return -1;
- direct_writes++;
- return total_written + n;
- }
-
- /*
- * If there's any data left, cache it.
- */
-
- if (n) {
- if (wcp->data_size) {
- abutted_writes++;
- DEBUG(9,("abutted write (%u)\n", abutted_writes));
- } else {
- init_writes++;
- }
- memcpy(wcp->data+wcp->data_size, data, n);
- if (wcp->data_size == 0) {
- wcp->offset = pos;
- num_write_caches++;
- }
- wcp->data_size += n;
- DEBUG(9,("cache return %u\n", (unsigned int)n));
- total_written += n;
- return total_written; /* .... that's a write :) */
- }
+ write_path, fsp->fh->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
+ (double)wcp->offset, (unsigned int)wcp->data_size ));
+
+ flush_write_cache(fsp, WRITE_FLUSH);
+ }
+ }
+
+ /*
+ * If the write request is bigger than the cache
+ * size, write it all out.
+ */
+
+ if (n > wcp->alloc_size ) {
+ ssize_t ret = real_write_file(fsp, data, pos, n);
+ if (ret == -1) {
+ return -1;
+ }
+
+ if (pos + ret > wcp->file_size) {
+ wcp->file_size = pos + n;
+ }
+
+ DO_PROFILE_INC(writecache_direct_writes);
+ return total_written + n;
+ }
+
+ /*
+ * If there's any data left, cache it.
+ */
+
+ if (n) {
+#ifdef WITH_PROFILE
+ if (wcp->data_size) {
+ DO_PROFILE_INC(writecache_abutted_writes);
+ } else {
+ DO_PROFILE_INC(writecache_init_writes);
+ }
+#endif
+ memcpy(wcp->data+wcp->data_size, data, n);
+ if (wcp->data_size == 0) {
+ wcp->offset = pos;
+ DO_PROFILE_INC(writecache_num_write_caches);
+ }
+ wcp->data_size += n;
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+ DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
+ (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
+
+ total_written += n;
+ return total_written; /* .... that's a write :) */
+ }
- return total_written;
+ return total_written;
}
/****************************************************************************
void delete_write_cache(files_struct *fsp)
{
- write_cache *wcp;
+ write_cache *wcp;
- if(!fsp)
- return;
+ if(!fsp) {
+ return;
+ }
- if(!(wcp = fsp->wcp))
- return;
+ if(!(wcp = fsp->wcp)) {
+ return;
+ }
- allocated_write_caches--;
+ DO_PROFILE_DEC(writecache_allocated_write_caches);
+ allocated_write_caches--;
- SMB_ASSERT(wcp->data_size == 0);
+ SMB_ASSERT(wcp->data_size == 0);
- free(wcp->data);
- free(wcp);
+ SAFE_FREE(wcp->data);
+ SAFE_FREE(fsp->wcp);
- fsp->wcp = NULL;
+ DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
}
/****************************************************************************
static BOOL setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
{
- ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
- write_cache *wcp;
-
- if (allocated_write_caches >= MAX_WRITE_CACHES) return False;
-
- if(alloc_size == 0 || fsp->wcp)
- return False;
-
- if((wcp = (write_cache *)malloc(sizeof(write_cache))) == NULL) {
- DEBUG(0,("setup_write_cache: malloc fail.\n"));
- return False;
- }
-
- wcp->file_size = file_size;
- wcp->offset = 0;
- wcp->alloc_size = alloc_size;
- wcp->data_size = 0;
- if((wcp->data = malloc(wcp->alloc_size)) == NULL) {
- DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
- (unsigned int)wcp->alloc_size ));
- free(wcp);
- return False;
- }
-
- fsp->wcp = wcp;
- allocated_write_caches++;
-
- return True;
+ ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
+ write_cache *wcp;
+
+ if (allocated_write_caches >= MAX_WRITE_CACHES) {
+ return False;
+ }
+
+ if(alloc_size == 0 || fsp->wcp) {
+ return False;
+ }
+
+ if((wcp = SMB_MALLOC_P(write_cache)) == NULL) {
+ DEBUG(0,("setup_write_cache: malloc fail.\n"));
+ return False;
+ }
+
+ wcp->file_size = file_size;
+ wcp->offset = 0;
+ wcp->alloc_size = alloc_size;
+ wcp->data_size = 0;
+ if((wcp->data = (char *)SMB_MALLOC(wcp->alloc_size)) == NULL) {
+ DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
+ (unsigned int)wcp->alloc_size ));
+ SAFE_FREE(wcp);
+ return False;
+ }
+
+ memset(wcp->data, '\0', wcp->alloc_size );
+
+ fsp->wcp = wcp;
+ DO_PROFILE_INC(writecache_allocated_write_caches);
+ allocated_write_caches++;
+
+ DEBUG(10,("setup_write_cache: File %s allocated write cache size %lu\n",
+ fsp->fsp_name, (unsigned long)wcp->alloc_size ));
+
+ return True;
}
/****************************************************************************
void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
{
- if(fsp->wcp) {
- flush_write_cache(fsp, SIZECHANGE_FLUSH);
- fsp->wcp->file_size = file_size;
- }
+ if(fsp->wcp) {
+ /* The cache *must* have been flushed before we do this. */
+ if (fsp->wcp->data_size != 0) {
+ pstring msg;
+ slprintf(msg, sizeof(msg)-1, "set_filelen_write_cache: size change \
+on file %s with write cache size = %lu\n", fsp->fsp_name, (unsigned long)fsp->wcp->data_size );
+ smb_panic(msg);
+ }
+ fsp->wcp->file_size = file_size;
+ }
}
/*******************************************************************
ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
{
- write_cache *wcp = fsp->wcp;
- size_t data_size;
+ write_cache *wcp = fsp->wcp;
+ size_t data_size;
+ ssize_t ret;
+
+ if(!wcp || !wcp->data_size) {
+ return 0;
+ }
+
+ data_size = wcp->data_size;
+ wcp->data_size = 0;
- if(!wcp || !wcp->data_size)
- return 0;
+ DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
- data_size = wcp->data_size;
- wcp->data_size = 0;
+ DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
+ fsp->fh->fd, (double)wcp->offset, (unsigned int)data_size));
- num_write_caches--;
+#ifdef WITH_PROFILE
+ if(data_size == wcp->alloc_size) {
+ DO_PROFILE_INC(writecache_num_perfect_writes);
+ }
+#endif
- flush_reasons[(int)reason]++;
+ ret = real_write_file(fsp, wcp->data, wcp->offset, data_size);
- DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
- fsp->fd, (double)wcp->offset, (unsigned int)data_size));
+ /*
+ * Ensure file size if kept up to date if write extends file.
+ */
- if(data_size == wcp->alloc_size)
- num_perfect_writes++;
+ if ((ret != -1) && (wcp->offset + ret > wcp->file_size)) {
+ wcp->file_size = wcp->offset + ret;
+ }
- return real_write_file(fsp, wcp->data, wcp->offset, data_size);
+ return ret;
}
/*******************************************************************
sync a file
********************************************************************/
-void sys_fsync_file(connection_struct *conn, files_struct *fsp)
+void sync_file(connection_struct *conn, files_struct *fsp, BOOL write_through)
+{
+ if (fsp->fh->fd == -1)
+ return;
+
+ if (lp_strict_sync(SNUM(conn)) &&
+ (lp_syncalways(SNUM(conn)) || write_through)) {
+ flush_write_cache(fsp, SYNC_FLUSH);
+ SMB_VFS_FSYNC(fsp,fsp->fh->fd);
+ }
+}
+
+/************************************************************
+ Perform a stat whether a valid fd or not.
+************************************************************/
+
+int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
{
- if(lp_strict_sync(SNUM(conn)) && fsp->fd != -1) {
- flush_write_cache(fsp, SYNC_FLUSH);
- conn->vfs_ops.fsync(fsp->fd);
- }
+ if (fsp->fh->fd == -1) {
+ return SMB_VFS_STAT(fsp->conn, fsp->fsp_name, pst);
+ } else {
+ return SMB_VFS_FSTAT(fsp,fsp->fh->fd, pst);
+ }
}
git.samba.org / sfrench / samba-autobuild / .git / blobdiff